NC1009: Metabolic Relationships in Supply of Nutrients for Lactating Cows (NC-185)

(Multistate Research Project)

Status: Inactive/Terminating

Project Menu

SAES-422 Reports

Annual/Termination Reports:

[12/23/2002] [11/17/2003] [08/08/2005] [12/16/2005] [12/15/2006] [01/23/2008]

Date of Annual Report: 12/23/2002

Report Information

Annual Meeting Dates: 10/21/2002 - 10/22/2002
Period the Report Covers: 01/01/2002 - 12/01/2002

Participants

Participants Attachment:

Attachment

Brief Summary of Minutes

Twenty-eight scientists participated in the annual meeting of the NC-1009 (formerly NC-185) Technical Committee in Salt Lake City on October 21 and 22, 2002. Henry Tyrrell, CSREES representative, updated the group with relevant national agricultural issues and policies. Steve Slack, administrative advisor, explained the administrative details that must be completed for continuation of a successful regional project. Each attending scientist reported on current activities as related to each of the three objectives. Scientific contributions of individual stations are summarized in the 2002 Annual Report. Information generated in the project is useful for (1) predicting lactation performances, (2) formulating diets for more efficient milk production, and (3) minimizing negative impact on the environment.

Accomplishments

Objective 1 To quantify properties of feeds that determine the availability of nutrients critical to milk production. Major findings under Objective 1 during 2002 include: Increasing post-ruminal fermentation of highly available fiber was postulated to increase the proportion of manure N in feces and decrease that in urine. Abomasal infusion of pectin tended to increase the proportion of fecal N (presumably bacterial N), which potentially could decrease ammonia N volatilization from dairy waste and decrease the negative impact on air quality (WI). Alfalfa silage and corn silage vary considerably in protein and rumen-degraded protein concentrations and might require different grain and protein supplementation strategies to convert the dietary protein more efficiently into milk protein and reduce urinary N excretion (USDA-DFRC). An intermediate protein concentration in the diet (16.5%) was most efficient, regardless of forage source. Because N can volatilize but P does not, the ratio of N:P before and after manure storage is a good indicator of N loss. Liquid slurry storage seemed the most efficient system for conserving N in manure, but 12 to 27% of N excreted still was lost into the atmosphere. In other research at USDA-DFRC, increasing dietary P from 0.38 to 0.48% or from 0.37 to 0.57% had no effect on reproductive measurements. Although the duration of estrus decreased with increasing milk production, the widespread notion in the field that increasing P concentration can increase ‘strength of heat‘ (duration of estrus) was disproven. Phosphorous availabilities of several feed ingredients were determined to be slightly higher than NRC (2001) values, further documenting that P does not need to be increased as a safety factor in dairy rations. Mechanically delinted cottonseeds were found to be of similar feeding value to that of whole linted cottonseeds, providing increased flexibility for use of whole cottonseeds in dairy rations. The bioavailability of two commercial rumen-protected methionine products or the isopropyl ester of 2-hydroxy-4-methylthio butanoic acid (HMBi) was examined at NH. After balancing diets to be limiting in methionine and assuming a bioavailability of 80% for Smartamine M, HMBi was estimated to have bioavailability of 34 to 42%. Methionine bioavailability was estimated to be 50% and that of Mepron to be 40%. Bioavailability of unprotected lysine was virtually 0 and certainly much lower than the value of 20% that is sometimes used in the field. To elucidate the role of low pH in fiber digestibility in high-producing dairy cattle fed high-grain rations, three concentrations of sucrose were added to in vitro batch cultures of rumen microbes (FL). Microbial yield increased rapidly, plateaued, and started decreasing. Bacteria stored more dextran ("microbial glycogen") with increasing sucrose. Increasing the pH of the medium prevented sucrose-mediated declines in fiber digestibility. Patulin, a mycotoxin that can contaminate fermented feeds, linearly decreased microbial N flow, and all concentrations of patulin decreased acid-detergent fiber digestibility in continuous culture of rumen microbes (MN and FL). Source of dietary fat had minor effects on microbial N flow or digestibility. A novel legume, Illinois bundleflower (Desmanthus illinoensis) was shown to have potential to be useful for grazing ruminants. As an estimation of the importance of microbial populations in protein nutrition of dairy cattle, solid-associated bacteria had lower crude protein percentage than did liquid-associated bacteria, but both fractions have high (91.6 to 96.6%) true intestinal digestibility of protein. Scientists at OH described an improved procedure to isolate ruminal protozoa without biasing distribution of protozoal genera relative to the starting ruminal fluid and to decrease contamination by bacteria. This procedure is necessary to be used as a standard preparation to quantify protozoal N by real-time polymerase chain reaction. Such work is necessary to improve prediction of microbial N flow to the duodenum by models. They also demonstrated that analysis of bacterial community structure by ribosome intergenic spacer region analysis has potential utility to document changes in populations of ruminal bacteria and to prioritize further studies to assess those changes. Scientists at PA in cooperation with others at IN and AL showed that prepartal dietary monensin altered ruminal production rates of volatile fatty acids, although dry matter intake had a greater overall effect on production of those acids. A continuous culture system was used to simulate effects of concentrate supplementation to cows on pasture (PA). Concentrate supplementation decreased pH in the fermenters but did not affect fiber digestibility at the same intake of pasture. Diets to lactating cows were top-dressed with five sources of (DHA). Supplementation of diets with docosahexaenoic acid (DHA) increased liver DHA concentration, regardless of ruminal protection, but also depressed dry matter intake (IN). These results still might be useful to improve the healthfulness of milk for humans. Other studies at IN used DNA microarray technology to identify genes that responded to physiological changes, especially genes regulating glucose synthesis and urea cycle activity in the liver. Gene transcript variants of pyruvate carboxylase seem important in the cow‘s adaptability from the dry period to the much higher metabolic demands of lactation. Feed restriction or force-feeding through rumen cannula of feed for dry cows did not improve but tended to decrease feed intake and milk production post-partum. Although consumption of pasture increased conjugated linoleic acid (CLA) concentration in milk compared with feeding of conserved forages, supplementation of extruded soybeans (rich in linoleic acid, the precursor to CLA) did not increase milk CLA further (UT). When fed the same diets, Brown Swiss produced milk with higher CLA concentrations than did Holsteins or Jerseys. Aryshires and Holsteins had higher CLA concentrations than did Guernseys and Jerseys. Research at KS indicated that 4 X milking during the first 30 days of lactation improved milk yield but not after cows were switched to 2 X milking on day 31 of lactation. Early postpartal estradiol cypionate therapy increased pregnancy rates but decreased milk yields when cows were milked 4 X daily unless treated with BST. Substitution of digestible fiber for a portion of dietary starch improves dry matter intake during the first 90 days of lactation and milk yield after 90 days in milk. Soyhull substitution for corn increased ruminal fiber digestibility and decreased digestibility of nonstructural carbohydrate (IL). Concomitantly, milk fat percentage increased. Flow of nitrogenous components to the small intestine was unaffected by treatment. Soyhulls could contribute satisfactorily up to 30% of the diet before limiting energy for milk production. Objective 2 To quantify metabolic interactions among nutrients that alter synthesis of milk. Major findings under Objective 2 during 2002 include: Sunflower and canola seeds are readily available oilseeds with potential to increase the concentration of CLA in milk (ND). Both sources increased concentrations of CLA and one of its metabolic precursors, vaccenic acid, in milk. Feed-grade urea that was coated with a polymer to slow its breakdown to ammonia in the rumen was not effective at decreasing N excretion in dairy waste. A mixture of fungal fibrolytic enzymes supplemented to dairy diets have potential to improve dry matter digestibility and influence milk production (VT). Faster growth decreases feed and total costs of dairy heifer raising but also seems to decrease milk production capabilities of those heifers in subsequent lactation (MI). On the basis of studies with intramammary infusion of hormones, insulin-like growth factor I seems to increase, but leptin seems to decrease the proliferation of mammary parenchymal epithelial cells in prepubertal heifers. Feeding calves to gain about 700 grams/day from two to eight weeks of age enhanced mammary development. However, feeding for faster growth after weaning but before puberty increased deposition of mammary adipose tissue. These results from MI demonstrate that we can adapt this knowledge to lessen the nutritional impairment of mammogenesis by managing heifer body condition. Studies at AL and PA indicate that feeding monensin prepartally had no effect on postpartal plasma amino acid concentrations. Accumulation of lipid in the liver decreases feed intake and is often a precursor event to ketosis and other metabolic problems occurring after calving (SD). Rumen-protection of fructose improved the carbohydrate status of dairy cows, preventing the onset of fatty liver and ketosis. Feeding whey (a by-product of cheese-making) containing lactose might increase significantly the amount of butyric acid produced by ruminal microbes, thereby increasing the surface area of rumen papillae for absorption of volatile fatty acids from the rumen. Glycerol, which is a derivative of soy-diesel production, seemed to prevent ketosis in cows during early lactation. To study the disparity in the amount of amino acids that disappear from the small intestine and the net absorption measured by catheterization of the venous blood vessels, intestinal mucosa cells were incubated with radiolabeled glucose, glutamate, or glutamine (MD and USDA-BARC). Results to date indicate that glucose/glutamine and glutamine/glutamate seem to be interchangeable as oxidative substrates in the mucosal cells. Feeding increasing amounts of calcium salts of trans long-chain fatty acids linearly decreased dry matter intake and milk fat percentage (MD). Calcium salts of CLA decreased milk fat percentage by 24% compared with the control. The amount of CLA reaching the duodenum is relatively low compared with the amount produced by intestinal desaturase from trans monounsaturated precursors. Subcutaneously injected glucagon has been used to treat (starting on day 8 for 14 days of lactation) and to prevent (starting on day 1) fatty liver disease in dairy cows. Blood metabolites demonstrate the usefulness of glucagon administration to treat cows older than 3.5 years but not those younger than that age. These changes occur without compromising lactation performance or reproductive fertility. It also increased blood glucose concentration linearly and decreased plasma. Fatty liver development seems associated with inflammatory response (IA). Objective 3 To use these quantitative relationships to challenge and refine computer-based nutrition systems for dairy cattle. Major findings under Objective 3 during 2002 include: Separation and quantification of milk proteins by electrophoresis is being used for the development of a mammary submodel of milk synthesis at DE. Scientists at CA demonstrated how to use SAS to stimulate metabolic data. They demonstrated the importance of making sure that a final solution produced from software is indeed the best solution (iteration reaches a "global" minimal sum of squares) rather than a "local" (i.e., not unique) solution. The California cow model "Molly" was challenged with serum amino acid data and corresponding model inputs derived from experimentation by WA scientists. The model simulated the use of amino acids for muscle and milk protein synthesis and responded as expected to an increase in methionine supply by sparing muscle tissue while supplying adequate amounts for milk production. Research at Purina Mills Inc. is focused on development of a new model to predict VFA concentration in the rumen.

Publications

Refereed publications of NC-1009 (formerly NC-185) Committee members during 2002 Abu-Ghazaleh, A.A., D.J. Schingoethe, A.R. Hippen, and L.A. Whitlock. 2002. Feeding fish meal and extruded soybeans enhances the conjugated linoleic acid (CLA) content of milk. J. Dairy Sci. 85:624-631. Agca, C., R.B. Greenfield, J.R. Hartwell, and S.S. Donkin. 2002. Cloning of bovine liver cytosolic and mitochondrial phosphoenolpyruvate carboxykinase and characterization during the transition to lactation. Physiol. Genom. (Accepted). Auchtung, T.L., D.J. Baer, R.A. Erdman, S.M. Barao, and G.E. Dahl. 2002. Relation of growth hormone response to growth hormone-releasing hormone to estimation of milk production via deuterium oxide dilution in beef cattle. J. Anim. Sci. 80:1270-1274. Bargo, F., L.D. Muller, G.A. Varga, J.E. Delahoy, and T.W. Cassidy. Ruminal digestion and fermentation of high producing dairy cows with three different feeding systems combining pasture and total mixed rations. J. Dairy Sci. 85:2964-2973. Bargo, F., G.A. Varga, L.D. Muller, and E.S. Kolver. 2002. Digestion of pasture only and pasture plus concentrate diets during continuous culture fermentation. J. Dairy Sci. (In press). Bequette, B.J., C.E. Kyle, L.A. Crompton, S.E. Anderson, and M.D. Hanigan. 2002. Endocrine and substrate regulation of protein metabolism in lactating goats. J. Dairy Sci. (In press). Bequette, B.J., C.E. Kyle, L.A. Crompton, A. G. Calder, and M.D. Hanigan. 2002. Protein metabolism in lactating goats subjected to the insulin clamp. J. Dairy Sci. 85:1546-1555. Bobe, G., R.N. Sonon, B.J. Ametaj, J.W. Young, and D.C. Beitz. 2003. Metabolic responses of lactating dairy cows to single and multiple injections of glucagon. J. Dairy Sci. (Accepted). DeFrain, J.M., J.E. Shirley, E.C. Titgemeyer, A.F. Park, and R.T. Ethington. 2002. Impact of feeding a raw soybean hull-condensed corn steep liquor pellet on induced subacute ruminal acidosis in lactating cows. J. Dairy Sci. 85:2000-2008. DeFrain, J.M., J.E. Shirley, E.C. Titgemeyer, A.F. Park, and R.T. Ethington. 2002. A pelleted combination of raw soyhulls and condensed corn steep liquor for lactating dairy cows. J. Dairy Sci. (Accepted). DeFrain, J.M., J.E. Shirley, K.C. Behnke, E.C. Tiggemeyer, and R.T. Ethington. 2002. Development and evaluation of a pelleted feedstuff containing condensed corn steep liquor and raw soybean hulls for dairy cattle diets. J. Feed Sci. Technol. (Accepted). Dhiman, T.R., M.S. Zaman, R.R. Gimenez, J.L. Walters, and R. Treacher. 2002. Efficacy of cellulase and xylanase enzyme application on forage prior to feeding for dairy cows. Anim. Feed Sci. Technol. 101:114-125. Dhiman, T.R., M.S. Zaman, I.S. MacQueen, and R.L. Boman. 2002. Influence of corn processing and frequency of feeding on cow performance. J. Dairy Sci. 85:217-226. Firkins, J.L., D.I. Harvatine, J.T. Sylvester, and M.L. Eastridge. 2002. Lactation performance by dairy cows fed wet brewers grains or whole cottonseed to replace forage. J. Dairy Sci. 85:2662-2668. Galo, E., S.M. Emmanuele, C.J. Sniffen, J.H. White, and J.R. Knapp. 2003. Evaluation of slow-release urea product on nitrogen balance in lactating Holsteins. J. Dairy Sci. (Accepted). Guan, X., B.J. Bequette, A.G. Calder, P.K. Ku, K.N. Ames, and N.L. Trottier. 2002. Amino acid availability affects amino acid trans-membrane transport of amino acids and protein metabolism in the porcine mammary gland. J. Nutr. 132:1224-1234. Hall, M.B. and C. Jerejk. 2001. Differences in yields of microbial crude protein from in vitro fermentation of carbohydrates. J. Dairy Sci. 84:2486-2493. Hanigan, M.D., B.J. Bequette, L.A. Crompton, J. France. 2001. Modelling mammary amino acid metabolism. Livest. Prod. Sci. 70:63-78. Hanigan, M.D., L.A. Crompton, B.J. Bequette, J.A.N. Mills, and J. France. 2002. Modelling mammary amino acid metabolism in the lactating cow: Pattern and sensitivity analyses and an independent challenge. J. Theor. Biol. 217:311-330. Harvatine, D.I., J.L. Firkins, and M.L. Eastridge. 2002. Whole linted cottonseed as a forage substitute fed with ground or steam-flaked corn: Digestibility and performance. J. Dairy Sci. 85:1976-1987. Harvatine, D.I., J.E. Winkler, M. Devant-Guille, J.L. Firkins, N.R. St-Pierre, B.S. Oldick, and M.L. Eastridge. 2002. Whole linted cottonseed as a forage substitute: Fiber effectiveness and digestion kinetics. J. Dairy Sci. 85:1988-1999. Hughes, C.L. and T.R. Dhiman. 2002. Dietary compounds in relation to dietary diversity and human health. J. Medicinal Food 5:51-68. Mabjeesh, S.J., Kyle, C.E., MacRae, J.C., and Bequette, B.J. 2002. Vascular sources of amino acids for milk protein synthesis in goats at two stages of lactation. J. Dairy Sci. 85:919-929. Ordway, R.S., V. Ishler, and G.A. Varga. 2002. Effect of sucrose supplementation on dry matter intake, milk (yield) and blood metabolites of periparturient Holstein dairy cows. J. Dairy Sci. 85:879-888. Park, A.F., J.E. Shirley, E.C. Titgemeyer, M.J. Meyer, M.J. VanBaale, and M.J. VandeHaar. 2002. Effect of protein level in prepartum diets on metabolism and performance of dairy cows. J. Dairy Sci. 85:1815-1828. Perkins, K.H., M.J. VandeHaar, J.L. Burton, J.S. Liesman, R.J. Erskine, and T.H. Elsasser. 2002. Clinical responses to intramammary endotoxin infusion in dairy cows subjected to feed restriction. J. Dairy Sci. 85:1724-1731. Piperova, L.S., J. Sampugna, B.B. Teter, K.F. Kalscheur, M.P. Yurawecz, Y. Ku, K.M. Morehouse, and R.A. Erdman. 2002. Duodenal and milk trans octadecenoic acid and conjugated linoleic acid (CLA) isomers indicate that postabsorptive synthesis is the predominant source of cis-9-containing CLA in lactating dairy cows. J. Nutr. 132:1235-1241. Schroeder, J.W., W.L. Keller, and C.S. Park. 2002. Glucose restriction and refeeding regimen alters proliferation and differentiation of HC11 mammary cells. In Vitro Cell Dev. Biol. Anim. 38:135-136. Schroeder, J.W. 2002. Optimizing the level of wet corn gluten feed in the diet of lactating dairy cows. J. Dairy Sci. 84:1669-1678. Schwab, C.G., T.P. Tylutki, R.S. Ordway, C. Sheaffer, and M.D. Stern. 2003. New concepts and developments in forage and feedstuff analysis and applications to ruminant nutrition: Characterization of proteins in feeds. J. Dairy Sci. (Accepted). Silva, L.F.P., M.J. VandeHaar, B.K. Whitlock, R.P. Radcliff, and H.A. Tucker. 2002. Short communication: Relationship of body growth to mammary development in dairy heifers. J. Dairy Sci. 85:(In press). Silva, L.F.P., M.J. VandeHaar, M.S. Weber-Nielsen, and G.W. Smith. 2002. Evidence for a local effect of leptin on bovine mammary gland. J. Dairy Sci. 85:(In press). Tapia, M.O., M.D. Stern, R.L. Koski, A. Bach, and M.J. Murphy. 2002. Effects of patulin on microbial fermentation in continuous culture fermenters. Anim. Feed Sci. Technol. 97:239-246. Tyler, P.A. and K.A. Cummins. 2002. Effect of dietary ascorbyl-2-phosphate on immune function of dairy heifers following transport to a rearing facility. J. Dairy Sci. (In press). Whitlock, B.K., M.J. VandeHaar, and H.A. Tucker. 2002. Effect of dietary protein on prepubertal mammary development in rapidly growing dairy heifers. J. Dairy Sci. 85:1516-1525. Book chapters and reviews during 2002 Bequette, B.J. 2003. Amino acid metabolism in animals: An overview. In Amino Acids in Animal Nutrition [J.P.F. D‘Mello, editor] Wallingford: CABI Publishing. Bequette, B.J., H. Lapierre, and M.D. Hanigan. 2003. Amino acid uptake by the mammary gland of lactating ruminants. In Amino Acids in Animal Nutrition [J.P.F. D‘Mello, editor] Wallingford: CABI Publishing. Non-refereed publications during 2002 Bateman, H.G. II and J.H. Clark. 2002. The use of computer models to predict passage of crude protein and amino acids to the small intestine of lactating cows. Illinois Dairy Report. Pp. 57-59. Bequette, B.J. 2002. Amino acid metabolism in dairy cows. 49th Maryland Nutr. Conf. Feed Mfgrs. Blevins, C.A., J.J. Aberle, J.E. Shirley, B.A. Hensley, S.M. Tiffany, and J.S. Stevenson. 2002. Milking frequency, estradiol cypionate, and bST alters milk yield and reproductive outcomes in dairy cows. KSU Dairy Day Report of Progress 898:11. Burgos, M.V., J.E. Shirley, and E.C. Titgemeyer. 2002. Comparative study of three expeller process soybean meals in diets for lactating dairy cows. KSU Dairy Day Report of Progress 898:8. Donkin, S.S. 2002. Rumen-protected choline: Potential for improving health and production in dairy cows. Tri-State Dairy Nutr. Conf. Proc. Pp. 55-66. Eicher, S.D., K.A. McMunn, H.M. Hammon, and S.S. Donkin. 2002. Toll-like receptors and acute phase cytokine gene expression in dexamethasone and growth hormone treated calves. Submitted to Cytokines and Interferons 2002, the Joint Meeting of The International Society for Interferon and Cytokine Research, The Society for Leukocyte Biology, The International Cytokine Society, and The European Cytokine Society, Turin, Italy. Ferdinand, E.E., J.E. Shirley, E.C. Titgemeyer, J.M. DeFrain, A.F. Park, D.E. Johnson, and R.T. Ethington. 2002. Diet digestibility and rumen traits in response to feeding wet corn gluten feed and a pellet consisting of raw soybean hull-corn steep liquor. KSU Dairy Day Report of Progress 898:6. Ferdinand, E.E., J.E. Shirley, E.C. Titgemeyer, J.M. DeFrain, A.F. Park, D.E. Johnson, and R.T. Ethington. 2002. Complete lactation performance of cows fed wet corn gluten feed and pellet consisting of raw soybean hulls and corn steep liquor. KSU Dairy Day Report of Progress 898:7. Hall, M.B. 2002. Working with sugars (and molasses). Proc. 13th Annu. Florida Ruminant Nutr. Symp., Gainesville, FL. Pp. 149-161. Hall, M.B. 2002. Starch: Analysis, availability and feeding. Proc. Cornell Nutr. Conf., Syracuse, NY. Hall, M.B. 2002. Working with non-NDF carbohydrates with manure evaluation and environmental considerations. Mid-South Ruminant Nutr. Conf., Dallas, TX. Hammond, A., J.E. Shirley, M.V. Scheffel, E.C. Titgemeyer, and J.S. Stevenson. 2002. Performance of dairy heifers fed high forage diets supplemented with bambermycins, lasalocid, or monensin. KSU Dairy Day Report of Progress 898:10. Klopfenstein, T., R. Angel, G.L. Cromwell, G.E. Erickson, D.G. Fox, C. Parsons, L.D. Satter, and A.L. Sutton. 2002. Animal diet modification to decrease the potential for nitrogen and phosphorus pollution. CAST Issue Paper. Number 21. Ames, IA. Miller, W.F., J.E. Shirley, E.C. Titgemeyer, M.J. Brouk, and M.V. Scheffel. 2002. Comparative value of full-fat corn germ, whole cottonseed, and tallow as energy sources for lactating dairy cows. KSU Dairy Day Report of Progress 898:9. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, J.M. DeFrain, E.E. Ferdinand, N. Wallace, T.G. Nagaraja, and D.E. Johnson. 2002. Changes in ruminal microbial populations in transition dairy cows. KSU Dairy Day Report of Progress 898:5. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, J.M. DeFrain, E.E. Ferdinand, and D.E. Johnson. 2002. Metabolic changes during the transition period. KSU Dairy Day Report of Progress 898:3. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, J.M. DeFrain, E.E. Ferdinand, T.G. Nagaraja, and D.E. Johnson. 2002. Characteristic changes of ruminal fermentation in transition dairy cows. KSU Dairy Day Report of Progress 898:4. Schwab, C.G. 2002. Ruminally protected amino acids. In: Ency. Dairy Sci. H. Roginski, J.W. Fuquay, and P.F. Fox (eds). Underwood, J.P., J.K. Drackley, and J.H. Clark. 2002. Performance by Holstien cows fed different amounts and sources of supplemental protein prepartum and postpartum. Illinois Dairy Report. Pp. 60-61. Varga, G.A. and M. Pickett. 2002. Strategies for feeding the transition cow. Southwest Nutr. Conf., Houston, TX. Varga, G.A. 2002. Dry cow feeding management: New strategies. NE Bovine Pract. Conf., Syracuse, NY. Varga, G.A. 2002. Energy levels in transition diets-enough but not too much. Amer. Assoc. Bovine Pract., Madison, WI. Varga, G.A. 2002. Protein balance. Renaissance Technical Conf., Bucknell University. Published abstracts during 2002 Abu-Ghazaleh, A.A., D.J. Schingoethe, A.R. Hippen, K.F. Kalscheur, and L.A. Whitlock. 2002. Milk fatty acid profiles of cows fed fish oil with fat sources that differed in fatty acid profiles. J. Dairy Sci. 85 (Suppl. 1):316. Adams, S.E., C.J. Snifen, J.H. White, and J.R. Knapp. 2002. Effects of a fibrolytic enzyme supplement on digestion and nutrient utilization by dairy cows fed alfalfa hay and greass silage-based rations. J. Dairy Sci. 85:105. Agca, C. and S.S. Donkin. 2002. Differential expression of pyruvate carboxylase 5‘UTR variants during transition to lactation. J. Dairy Sci. (Suppl. 1):302. Aguerre, M.J., S. Marcot, H. Henselmeyer, and L.D. Satter. 2002. Availability of phosphorus in dairy feeds. J. Dairy Sci. 85(Suppl. 1):187. Ametaj, B.N., G. Bobe, J.W. Young, and D.C. Beitz. 2002. Chronic glucagon administration and lipoprotein composition in periparturient dairy cows. J. Dairy Sci. 85:1351-1352. Ametaj, B.N., B.J. Bradford, G. Bobe, Y. Lu, R. Nafikov, R.N. Sonon, J.W. Young, and D.C. Beitz. 2002. Acute phase response indicates inflammatory conditions may play a role in the pathogenesis fatty liver in dairy cows. J. Dairy Sci. 85(Suppl. 1):189. Bargo, F., G.A. Varga, L.D. Muller, and E.S. Kolver. 2002. Digestion of pasture only and pasture plus concentrate diets during continuous culture fermentation. J. Dairy Sci. 85(Suppl. 1):62. Blevins, C.A., J.J. Aberle, J.E. Shirley, B.A. Hensley, S.M. Tiffany, and J.S. Stevenson. 2002. Effect of milking frequency (MF), estradiol cypionate, and bST on milk yield and reproductive outcomes in dairy cows. J. Dairy Sci. 85(Suppl. 1):98. Bobe, G., B.N. Ametaj, Y. Lu, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on liver carbohydrates in lactating dairy cows. FASEB J. 16:A618. Bobe, G., B.N. Ametaj, R. Sonon, Y. Lu, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on liver lipid composition in lactating dairy cows. FASEB J. 16:A635. Bobe, G., B.N. Ametaj, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on milk yield and composition in lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):64. Bobe, G., B.N. Ametaj, R. Nafikov, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on plasma parameters in lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):65. Bobe, G., B.N. Ametaj, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on the health of lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):190. Bobe, G., B.N. Ametaj, D.C. Beitz, and J.W. Young. 2002. Effect of 14-day subcutaneous injections of several dosages of glucagon on reproductive success in lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):190. Bobe, G., B.N. Ametaj, Y. Lu, D.C. Betiz, and J.W. Young. 2002. Metabolic responses of lactating dairy cows to 14-day subcutaneous infusions of several dosages of glucagon. J. Dairy Sci. 85(Suppl. 1):275. Bobe, G., B.N. Ametaj, R.N. Sonon, D.C. Beitz, and J.W. Young. 2002. Effect of time and day of injection on plasma B-hydroxybutyrate, NEFA, and urea N during 14-day subcutaneous injections of several dosages of glucagon in dairy cows. J. Dairy Sci. 85(Suppl. 1):350. Bobe, G., B.N. Ametaj, R.N. Sonon, D.C. Beitz, and J.W. Young. 2002. Effect of time and day of injection on plasma glucose and insulin during 14-day subcutaneous injections of several dosages of glucagon in dairy cows. J. Dairy Sci. 85(Suppl. 1):350. Brown, E.G., M.J. VandeHaar, K.M. Daniels, J.S. Liesman, L.T. Chapin, and M.S. Weber-Nielsen. 2002. Increasing energy and protein intake of Holstein heifer calves increases mammary development. J. Anim. Sci. 80(Suppl. 1):80. Brown, E.G., M.J. VandeHaar, K.M. Daniels, J.S. Liesman, L.T. Chapin, and M.S. Weber-Nielsen. 2002. Effect of increasing energy and protein intake of Holstein heifer calves on growth. Proc. Midwest ASAS/ADSA meeting. Caperoon, K.A., M.D. Stern, C.C. Sheaffer, G.I. Crawford, and R.L.K. Hulbert. 2002. Evaluation of Illinois bundleflower as a grazing source for ruminants using dual flow continuous culture fermenters. J. Dairy Sci. 85(Suppl. 1):63. Capuco, A.V., S.E. Ellis, S.A. Hale, E. Long, R.A. Erdman, X. Zhao, and M.J. Paape. 2002. Lactation persistency: Insights from mammary cell proliferative studies. J. Dairy Sci. 85(Suppl. 1):2. Carlson, D.B., M.S. Laubach, W.L. Keller, J.W. Schroeder, J.H. Herbein, and C.S. Park. 2002. Effect of sunflower seed inclusion on conjugated linoleic acid concentrations in milk fat of Holstein cows. J. Dairy Sci. 85(Suppl. 1):196. Carlson, D.B., M.S. Laubach, D.E. Schimek, W.L. Keller, J.W. Schroeder, and C.S. Park. 2002. Body condition replenishment during the dry period and its effects on metabolic status and lactation of dairy cows. J. Dairy Sci. 85(Suppl. 1):276. Crawford, G.I., M.D. Stern, R.L.K. Hulbert, K.A. Caperoon, and B.L. Miller. 2002. Effect of fat source on microbial fermentation in continuous culture of rumen contents. J. Dairy Sci. 85(Suppl. 1):142. Crowder, S.A., J.E. Garrett, and S.S. Donkin. 2002. Effects of feeding encapsulated and unprotected docosahexaenoic acid on feed intake, milk production, milk composition, and fatty acid profile in dairy cows. J. Dairy Sci. 80(Suppl. 1):317. Davis, L.E., J.L. Liesman, M.S. VandeHaar, and M.S. Weber-Nielsen. 2002. Mitogenic effects of parenchymal tissue extracts from different regions within the heifer mammary gland. J. Anim. Sci. 80(Suppl. 1):80. Dhiman, T.R., M.S. Zaman, L. Kilmer, and D. Gilbert. 2002. Breed of dairy cow has influence on conjugated linoleic acid (CLA) content of milk. J. Dairy Sci. 85(Suppl. 1):315. Dhiman, T.R. 2002. Influence of soybean meal processing techniques on milk yield response of dairy cows. J. Dairy Sci. 85(Suppl. 1):245. Dominguez, D.D., V.R. Moriera, and L.D. Satter. 2002. Effect of feeding brown midrib-3 corn silage or conventional corn silage cut at either 23 or 71 cm on milk yield and milk composition. J. Dairy Sci. 85(Suppl. 1):385. Ferdinand, E.E., J.E. Shirley, E.C. Titgemeyer, J.M. DeFrain, and A.F. Park. 2002. Effect of feeding wet corn gluten feed and a raw soybean hull-corn steep liquor pellet on the performance of lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):69. Ferdinand, E.E., J.E. Shirley, E.C. Titgemeyer, J.M. DeFrain, and A.F. Park. 2002. The effect of feeding wet corn gluten feed and a raw soybean hull-corn steep liquor pellet on digestibility and rumen parameters. J. Dairy Sci. 85(Suppl. 1):70. Firkins, J.L., D.I. Harvatine, J.T. Sylvester, and M.L. Eastridge. 2002. Lactation performance by dairy cows fed wet brewers grains or whole cottonseed to replace forage. Proc. Midwest ASAS/ADSA meeting. Pp. 67-68. Galo, E., S.M. Emanuele, C.J. Sniffen, J.H. White, and J.R. Knapp. 2002. Effects of a slow-release urea product on nitrogen metabolism in lactating Holstein dairy cattle. J. Dairy Sci. 85(Suppl. 1):73. Hale, S.A., A.V. Capuco, and R.A. Erdman. 2002. Potential mechanisms for increased milk yield due to increased milking frequency during lactation. J. Dairy Sci. 85(Suppl. 1):22. Hall, M.B. 2002. Characterizating carbohydrates in feeds. J. Dairy Sci. 85(Suppl. 1):146. Hall, M.B. 2002. Challenges with non-fiber carbohydrate methods. J. Dairy Sci. 85(Suppl. 1):167. Hall, M.B. 2002. Seeking solutions for complex fiber analysis. Pittsburgh Conf., New Orleans, LA, Abstr. 696. Hall, M.B. and P.J. Weimer. 2002. Nutrient yields from in vitro fermentations of sucrose and neutral detergent fiber by mixed ruminal microorganisms. J. Dairy Sci. 85(Suppl. 1):183. Hill, B.E., S.L. Hankins, J.F. Kearney, J.D. Arseneau, D.T. Kelly, S.S. Donkin, B.T. Richert, and A.L. Sutton. 2002. Effects of feeding low phytic acid corn and phytase on phosphorus balance in lactating dairy cows. J. Dairy Sci. J. Dairy Sci. (Suppl. 1):44. Holtshausen, L. and M.B. Hall. 2002. Effect of medium pH on microbial crude protein yield, pH, and neutral detergent fiber digestion from fermentation of neutral detergent fiber and sucrose in vitro. J. Dairy Sci. 85(Suppl. 1):182. Ipharraguerre, I.R., Z. Shabi, J.H. Clark, and D.E. Freeman. 2002. Site of digestion when soyhulls replace corn in diets of dairy cows. J. Dairy Sci. 85(Suppl. 1):397. Ipharraguerre, I.R., R.S. Younker, J.H. Clark, E.P. Stanisewski, and G.F. Hartnell. 2002. Performance of lactating dairy cows fed glyphosate-tolerant corn (Event NK603). J. Dairy Sci. 85(Suppl. 1):358. Karnati, S.K.R., J.T. Sylvester, Z. Yu, B.A. Dehority, and J.L. Firkins. 2002. Amplification of protozoal 18S rDNA sequences from protozoa-enriched rumen samples from cows using a protozoal specific primer. Proc. Midwest ASAS/ADSA meeting. P. 69. Khanal, R.C., T.R. Dhiman, D.J. McMahon, and R.L. Boman. 2002. Influence of diet on conjugated linoleic acid content of milk, cheese, and blood serum. J. Dairy Sci. 85(Suppl. 1):142. Leonardi, C., F. Giannico, and L.E. Armentano. 2002. Effect of water addition on selective consumption (sorting) of dry diets by dairy cattle. J. Dairy Sci. 85 (Suppl. 1):62. Lopez, H., F.D. Karitz, V.R. Moriera, M.C. Wiltbank, and L.D. Satter. 2002. Effect of dietary phosphorus concentration on reproductive performance of lactating dairy cows. J. Dairy Sci. 85(Suppl. 1):364. Markantonatos, X., G.A. Varga, T. Cassidy, R. McGuffey, L. Richardson, and R. Tucker. 2002. Volatile fatty acid production rates of Holstein dairy cows provided monensin during the transition period. J. Dairy Sci. 85(Suppl. 1):105. McLaughlin, A.M., N.L. Whitehouse, E.D. Robblee, R.S. Ordway, C.G. Schwab, P.S. Erickson, and D.E. Putnam. 2002. Evaluation of ruminally unprotected lysine as a source of metabolizable lysine for high producing cows. J. Dairy Sci. 85 (Suppl. 1):23. Moallem, U., B. Teter, L. Piperova, J. Sampugna, and R.A. Erdman. 2002. Calcium salts of conjugated linoleic acid were more effective than calcium salts of trans fatty acids in reducing milk fat in lactating cows. J. Dairy Sci. 85(Suppl. 1):316. Nafikov, R.A., B.N. Ametaj, G. Bobe, J.W. Young, and D.C. Beitz. 2002. Prevention of fatty liver in transition dairy cows by glucagon. J. Dairy Sci. 85(Suppl. 1):21. Noftsger, S., J. Firkins, and N.R. St-Pierre. 2002. Effects of 2-hydroxy-4-(methylthio) butanoic acid (HMB) and dl-methionine on microbial growth, VFA production, and nutrient digestion in continuous culture. J. Dairy Sci. 85(Suppl. 1):240. Oliver, C., M.L. Bauer, J.W. Schroeder, W.L. Keller, C.S. Park. 2002. Dietary nucleotides enhance calf immune function. FASEB J. 16:A985. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, J.M. DeFrain, E.E. Ferdinand, N. Wallace, and T.G. Nagaraja. 2002. Characterization of microbial adaptation in dairy cows with changes in diet and lactational state. J. Dairy Sci. 85(Suppl. 1):404. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, J.M. DeFrain, and E.E. Ferdinand. 2002. Metabolic adaptations in dairy cows to changes in diet and lactational status. J. Dairy Sci. 85(Suppl. 1):186. Park, A.F., J.E. Shirley, E.C. Titgemeyer, R.C. Cochran, T.A. Wickersham, J.M. DeFrain, E.E. Ferdinand, A.K. Hammond, and D.G. Schmidt. 2002. Evaluation of markers used to predict digestibility in typical dairy diets. J. Dairy Sci. 85(Suppl. 1):1352. Qiu, X., M.L. Eastridge, J.L. Firkins, K.E. Griswold, and G.A. Apgar. 2002. Effects of DMI, addition of buffer, and source of fat on duodenal flow and milk concentration of conjugated linoleic acid and trans-C18:1 in dairy cows. J. Dairy Sci. 85(Suppl. 1):313. Raman, P., S.S. Donkin, and M.E. Spurlock. 2002. Comparative effect of leptin on hepatic gluconeogenesis in rat hepatocytes vs. porcine hepatocytes. Proc. 84th Annu. meeting The Endocrine Society, P. 587. Santos, H.H.B., S. Lardoux, V.R. Moriera, and L.D. Satter. 2002. Effect of dietary protein content and alfalfa-corn silage ratios on nitrogen excretion and milk production of late lactation cows. J. Dairy Sci. 85(Suppl. 1):244. Schwab, C.G., T.P. Tylutki, R.S. Ordway, C. Sheaffer, and M.D. Stern. 2002. New concepts and developments in forage and feedstuff analysis and applications to ruminant nutrition: Characterization of proteins in feeds. J. Dairy Sci. 85(Suppl. 1):146. Silva, L.F.P., M.J. VandeHaar, and M.S. Weber-Nielsen. Intramammary infusion of IGF-I increases BrdU-labeling in mammary epithelial cells of prepubertal heifers. J. Anim. Sci. 80 (Suppl. 1):20. Silva, L.F.P., M.J. VandeHaar, M.S. Weber-Nielsen, and B.E. Etchebarne. Leptin reduces proliferation of a bovine mammary epithelial cell line (MAC-T). J. Anim. Sci. 80(Suppl. 1):338. Sylvester, J.T., S.K.R. Karnati, Z. Yu, C.J. Newbold, B.A. Dehority, M. Morrison, and J.L. Firkins. 2002. Advancements in the quantification of protozoal nitrogen flow to the duodenum using molecular-based analyses. J. Dairy Sci. 85(Suppl. 1):182. Townsend, J.R., D.E. Moody, and S.S. Donkin. 2002. Evaluation of the use of a human cDNA microarray to profile hepatic gene expression in transition dairy cows. J. Dairy Sci. 85(Suppl. 1):195. VandeHaar, M.J., L.F.P. Silva, B.E. Etchebarne, and M.S. Weber-Nielsen. 2002. Potential role for leptin in mammary development of heifers. J. Anim. Sci. 80(Suppl. 1):80. Weimer, P.J. and M.B. Hall. 2002. Gas production kinetics and fermentation end product formation from neutral detergent fiber and sucrose by mixed ruminal microorganisms. J. Dairy Sci. 85(Suppl. 1):361. Theses and Dissertations Adams, S.E. 2002. Effects of a fibrolytic enzyme supplement on nutrient digestion and utlization by dairy cattle fed alfalfa hay and grass silage-based rations. M.S. Thesis, Univ. of Vermont. Bobe, G. 2002. Metabolic responses of lactating dairy cows to exogenous glucagon. Dissertation, Iowa State Univ. Danahey, K.A. 2002. Calcium chloride fertilization of cool season grasses for dry cow forages. M.S. Thesis, Univ. of Vermont. Ferdinand, E.E. 2002. Response of lactating dairy cows to diets containing wet corn gluten feed or a raw soybean hull-corn steep liquor pellet. M.S. Thesis, Kansas State Univ. Galo, E. 2002. Effects of Optigen 1200 on nitrogen utilization in dairy cattle and whole farm nutrient balance. M.S. Thesis, Univ. of Vermont. Kuha, K.K. 2002. Chemical composition and small intestinal protein digestibility of various rumen microbial fractions. Sci. in Agr. Undergraduate Thesis, Univ. of Minnesota. Tapia, M.O. 2002. Patulin toxicity in sheep. Dissertation, Univ. of Minnesota.

Impact Statements

Developed methods for protozoal contribution to absorbed nutrients.
Demonstrated that N to P ratio in manure estimates N loss via manure.
NRC recommendations for N and P were supported.
Soyhulls can replace part of dietary corn.
Oil seeds and pasture increase conjugated linoleic acid and thus healthfulness of milk.
Glucagon will prevent and treat fatty liver in periparturient cows.
Molly computer program estimates use of metabolic paths for milk synthesis.

Date of Annual Report: 11/17/2003

Report Information

Annual Meeting Dates: 10/20/2003 - 10/21/2003
Period the Report Covers: 01/01/2003 - 12/01/2003

Participants

Armentano, Louis - University of Wisconsin;
Beitz, Don - Iowa State University;
Bequette, Brian - University of Maryland;
Cummins, Keith - Auburn University;
Dhiman, Tilak - Utah State University;
Donkin, Shawn - Purdue University;
Fadel, James - University of California;
Firkins, Jeffrey - Ohio State University;
Hanigan, Mark - Purina Mills, St. Louis;
Hippen, Arnold - South Dakota State University;
Knapp, Joanne - University of Vermont;
McGuffey, Ken Elanco, Inc. - guest;
McNamara, John - Washington State University;
Reynolds, Chris Ohio State University;
Schingoethe, David South Dakota State University;
Shirley, John - Kansas State University;
Slack, Steven - Administrative Advisor, Ohio State University;
Stern, Marshall - University of Minnesota;
Tyrrell, Henry - National Program Leader, USDA/CSREES, Washington DC;
VandeHaar, Michael - Michigan State University;
Varga, Gabriella - Pennsylvania State University

Brief Summary of Minutes

Minutes Attachment:

Attachment

Accomplishments

Objective 1 To quantify properties of feeds that determine the availability of nutrients critical to milk production. FL researchers showed that the accumulation of feed sugars into microbial storage polysaccharide is rapid and extensive. Thus, rates of sugar disappearance should be greater than the rate of appearance of fermentative end-products. Starch provided a more even availability of carbohydrate supply to support microbial protein synthesis than sucrose (table sugar) or citrus pulp, probably explaining the increased milk protein percentage. Increasing dietary concentration of lactose (sugar byproduct from milk processing) linearly increased dry matter intake (DMI) but had minor effects on other production variables except by linearly reducing milk-urea nitrogen (SD), which probably resulted from more efficient capture of dietary nitrogen. MN researchers reported that feeding a liquid by-product from monosodium glutamate production greatly elevated ammonia concentration in continuous culture fermenters, so the soybean meal control increased total amino acid (AA) flow from the fermenters. Ammonia will only be used to support microbial protein synthesis when it is synchronized with carbohydrate availability. NH documented rapid degradation of free lysine and a commercial source of a methionine derivative, but data confirmed a moderate degradability of an isopropyl ester of the methionine derivative. This work will help nutritionists provide feed AA escaping the rumen to complement the microbial protein AA. In order to improve the predictive accuracy of microbial AA flow to the duodenum, OH researchers documented significant progress toward development of a molecular-based technique to quantify protozoal protein. Fibrolytic enzymes and administration of malic acid to increase microbial activity did not affect milk production (IL). Insertion of a gene into corn to impart glyphosphate tolerance was shown not to affect the nutritional value of corn grain or silage (IL). Addition of long alfalfa hay or dry rolled corn into total mixed rations for recently calved cows had no significant impact on milk production characteristics (KS). Any potential benefit might depend on the degree of sorting of the total mixed rations. Some cows more actively sorted against the consumption of long hay particles, and this sorting was greater for cows in free-stall vs. tie-stall housing (WI). Still, there were no significant correlations between sorting characteristics and measurements of milk production or composition. The role of fatty acid intermediates in the rumen microbial biohydrogenation process (conversion of unsaturated fatty acids into saturated fatty acids) is being actively researched. AL, ND, UT, and SD researchers reported progress toward quantifying how fat from distillers grains, soybeans, and canola seeds influences the amount of trans fatty acids and conjugated linoleic acid (CLA, an intermediate of biohydrogenation that is a very potent anticancer agent) reaching the cows small intestine. Determining optimal processing and inclusion rates of these fat sources will help increase CLA concentration in milk fat without significantly depressing fat synthesis in the mammary gland. Addition of calcium oxide to extruded soybeans decreased biohydrogenation, as evidenced by increased concentration of linoleic acid in milk fat (UT). However, feeding calcium salts of CLA decreased DMI by cows and increased non-esterified fatty acid (NEFA) concentration in blood. Objective 2 To quantify metabolic interactions among nutrients that alter synthesis of milk. Increasing lactose concentration in the diet significantly affected the profile of volatile fatty acids, which could predispose the cow to a greater risk of developing ketosis (SD). Acetate and butyrate are ketogenic (promotes production of ketone bodies), but propionate is glucogenic (glucose production in the liver); increasing microbial production of propionate should reduce the risk of ketosis. When commercially prepared propionate was supplemented as either a salt with calcium or with chromium, both increased the rate of fatty acid synthesis from biopsied adipose tissue (WA). However, the chromium salt increased milk production, perhaps by affecting metabolism of the mammary gland. SD researchers, in collaboration with IA, showed that supplementation of glycerol (which is glucogenic) tended to decrease DMI but delayed onset and degree of mobilization of NEFA from adipose tissue. In contrast, partial substitution of fibrous byproducts for forage increased DMI and decreased concentration of NEFA in blood (PA). Although increased nutrient intake prepartum has been associated with increased DMI postpartum and thereby decreased need for tissue mobilization, IN researchers reported that force-feeding through rumen cannulas pre-calving tended to decrease DMI post-calving. Decreased NEFA concentration should be associated with decreased risk for development of ketosis. Although feeding glycerol was not as effective at decreasing risk of ketosis as oral drenching or administration with an esophageal tube (SD), feeding dry propylene glycol was effective (PA). Daily injection of the slow-release glucagon for a 2-week regimen, which promotes glucose production in the liver, appears to significantly reduce the risk of development of ketosis (IA and SD). Several researchers are using a mix of in vitro and in vivo techniques to quantify fluxes of nutrients and important metabolites that influence the supply of nutrients to the mammary gland compared with other competing tissues. Rumen epithelial cells metabolized a small amount of glucose in comparison with volatile fatty acids, lactate, and AA (MD). Duodenal mucosal cells had significant metabolic activity for metabolism of AA to Krebs cycle intermediates. These cells also appeared to have urea cycle activity, whereas rumen epithelial cells had limited ability to produce urea. They showed that about half of the glucose available from intestinal absorption or gluconeogenesis (glucose production) was used by the gastrointestinal tract in sheep. Based on a compilation of data from studies with cattle catheterized in various blood vessels, the liver appears to remove lactate from the blood when cows are in negative energy balance but releases lactate when they are in positive energy balance (OH). In such cases, lactate might be a precursor for fatty acid synthesis in the adipose tissue. VT researchers developed an immortalized cell line of bovine enterocytes (cells from the small intestine that can continue in culture without requiring fresh tissue). The gene expression and function of several AA transporters was documented. Data supported the conclusion that transport activity likely is controlled through cell signaling pathways that are responsive to typical metabolic hormones. Dairy cows selected for high milk production have the ability to partition nutrients toward the mammary gland rather than to adipose tissue. Based on DNA microarray techniques, the quantitative expression of hundreds of genes was compared for MN dairy cattle selected for high milk production vs. those not selected (5500 kg/d milk production differential). Prolactin receptor in the liver had significantly greater expression in the first two weeks of lactation for the high genetic merit cattle (VT working with MN). There was no difference between the ratio of two predominant receptor types, so they concluded that the receptors must be very sensitive to changes in blood prolactin concentration. Also, AL is evaluating protein turnover in recently calved cows. Mammary gland development is influenced by dietary factors during in key stages of heifer growth. Based on DNA microarray analyses of mammary gland biopsies, the hormone leptin was shown to counter-regulate insulin-like growth factor 1s ability to stimulate mammary cell growth through the expression of numerous genes (MI). Such data justified further in vivo studies to characterize the regulation of mammary development in heifers. Using similar approaches, IN researchers, in collaboration with PA and IA, documented changes in gene expression during the period immediately preceding and after calving. These findings stimulated subsequent studies to evaluate how lactation-regulating hormones impact the activity of targeted enzymes. In particular, they evaluated the expression of genes coding for the synthesis of pyruvate carboxylase and phosphoenol pyruvate carboxykinase, which are rate-limiting for gluconeogenesis in the liver. Increased glucose availability should increase lactose production in the mammary gland and therefore milk volume. MD researchers are studying the contribution of lactose synthesis from precursors other than blood glucose. Objective 3 To use these quantitative relationships to challenge and refine computer-based nutrition systems for dairy cattle. AL, CA, OH, PA, and VT researchers are deriving data that will help improve the parameterization of the mechanistic dairy cow metabolism model, Molly. The industry representative from Purina Mills developed a sub-component of Molly to describe the net AA removal by the portal-drained viscera for subsequent field use. The lower bound for true digestibility of protein was determined to be 80%, but more research is needed to derive coefficients for essential AA. With prediction errors ranging from 4 to 9%, the current system now allows Molly to correct for metabolic losses in AA that are absorbed from the small intestine but not available for milk protein synthesis. WA simulated increasing the energetic cost of metabolism by the portal-drained viscera in Molly (the version without the Purina correction). Increasing this energetic cost by up to 45% prevented the over-prediction of fat deposition compared with actual data. Recent in vivo data from OH are supporting the energetic cost of these tissues.

Publications

Refereed Articles of NC-1009 Committee Members AbuGhazaleh, A. A., D. J. Schingoethe, A. R. Hippen, K. F. Kalscheur, and L. A. Whitlock. 2002. Fatty acid profiles of milk and rumen digesta from cows fed fish oil, extruded soybeans, or their blend. J. Dairy Sci. 85:2266-2276. AbuGhazaleh, A. A., D. J. Schingoethe, L. A. Whitlock, A. R. Hippen, and K. F. Kalscheur. 2003. Milk conjugated linoleic acid from cows fed fish oil with fat sources that differed in fatty acid profiles. J. Dairy Sci. 86:944-953. Agca, C., C. A. Bidwell, and S. S. Donkin. 2003. Cloning of bovine pyruvate carboxylase and 5' untranslated region. Anim. Biotechnol. (Accepted). Ametaj, B.N., G. Bobe, Y. Lu, J.W. Young, and D.C. Beitz. Effect of sample preparation, length of time, and sample size on quantification of total lipids from bovine liver. J. Agr. Food Chem. 51:2105-2110. Bargo, F., L. D. Muller, G. A. Varga, J. E. Delahoy, and T. W. Cassidy. 2003. Ruminal digestion and fermentation of high producing dairy cows with three different feeding systems combining pasture and total mixed rations. J. Dairy Sci. 85:2964-2973. Beitz, D.C. Use of glucagon to prevent and treat fatty liver in transition dairy cows. Four-State Applied Nutrition and Management Proc., MWPS-4SD16, pp. 163-167. Bobe, G., B.H. Ametaj, J.W. Young, and D.C. Beitz. 2003. Effects of exogenous glucagon on lipids in lipoproteins and liver of lactating dairy cows. J. Dairy Sci. 86:2895-2903. Bobe, G., B.N. Ametaj, J.W. Young, and D.C. Beitz. 2003. Potential treatment of fatty liver with 14-day subcutaneous injections of glucagon. J. Dairy Sci. 86:3138-3147. Bobe, G., R.N. Sonon, B.N. Ametaj, M.W. Young, and D.C. Beitz. 2003. Metabolic responses of lactating cows to single and multiple subcutaneous injections of glucagon. J. Dairy Sci. 86:2072-2081. Britt, J. S., R. C. Thomas, N. C. Speer, and M. B.Hall. 2003. Efficiency of converting nutrient dry matter to milk in Holstein herds. J. Dairy Sci. (Accepted). DeFrain, J. M., J. E. Shirley, K. C. Behnke, E. C. Titgemeyer, and R. T. Ethington. 2002. Development and evaluation of a pelleted feedstuff containing condensed corn steep liquor and raw soybean hulls for dairy cattle diets. Anim. Feed Sci. Technol. 107:75-86. Dhiman, T. R., H. R. Bingham, and H. D. Radloff. 2003. Production response of lactating cows fed dried versus wet brewers grain in diets with similar dry matter content. J. Dairy Sci. 86:2914-2921. Dhiman, T. R., M. S. Zaman, R. R. Gimenez, J. L. Walters, and R. Treacher. 2002. Efficacy of cellulase and xylanase enzyme application on forage prior to feeding for dairy cows. Anim. Feed Sci. Technol. 101:114-125. Donkin, S. S, J. C. Velez, A. K. Totten, E. P. Stanisiewski, and G. F. Hartnell. 2003. Effects of feeding silage and grain from glyphosate-tolerant or insect-protected corn hybrids on feed intake, ruminal digestion, and milk production in dairy cattle. J. Dairy Sci. 86:1780-1788. Eicher, S. D., K. A. McMunn, H. M. Hammon, and S. S. Donkin. 2003. Toll-like receptors and acute phase cytokine gene expression in dexamethasone and growth hormone treated calves. J. Interferon Cytokine Res. (In Press). Galo, E., S. M. Emmanuele, C. J. Sniffen, J. H. White, and J. R. Knapp. 2003. Evaluation of a slow-release urea product on nitrogen balance in lactating Holsteins. J. Dairy Sci. 86:2154-2162. Griswold, K. E., G. A. Apgar, J. Bouton, and J. L. Firkins. 2003. Effect of urea supplementation and ruminal degradable protein concentration on microbial growth, digestibility and fermentation in continuous culture. J. Anim. Sci. 81:329-336. Grum, D. E., J. K. Drackley, and J. H. Clark. 2002. Fatty acid metabolism in liver of dairy cows fed supplemental fat and nicotinic acid during an entire lactation. J. Dairy Sci. 85:3026-3034. Hale, S. A., A. V. Capuco, and R. A. Erdman. 2003. Milk yield and mammary growth effects due to increased milking frequency during early lactation. J. Dairy Sci. 86:2061-2071. Hall, M. B. 2003. Challenges with nonfiber carbohydrate methods. J. Anim. Sci. (Accepted). Hammon, H. M., Y. Zbinden, H. Sauerwein, B. H. Breier, J. W. Blum, and S. S. Donkin. 2003. The response of the hepatic insulin-like growth factor system to growth hormone and dexamethasone in calves. Endocrinology (Accepted). Hanigan, M. D., L. A. Crompton, C. K. Reynolds, D. Wray-Cahen, M. A. Lomax, and J. France. An integrative model of amino acid metabolism in the liver of the lactating dairy cow. J. Theor. Biol. (Accepted). Ipharraguerre, I.R., and J.H. Clark. 2003. Soyhulls as an alternative feed for lactating dairy cows: A review. J. Dairy Sci. 85:1052-1073. Ipharraguerre, I.R., and J.H. Clark. 2003. Usefulness of ionophores for lactating dairy cows: A review. Anim. Feed Sci. Technol. 106:39-57. Ipharraguerre, I. R., R. R. Ipharraguerre, and J. H. Clark. 2002. Performance of lactating dairy cows fed varying amounts of soyhulls as a replacement for corn grain. J. Dairy Sci. 85:2905-2912. Ipharraguerre, I. R., Z. Shabi, J. H. Clark, and D. E. Freeman. 2002. Ruminal fermentation and nutrient digestion by dairy cows fed varying amounts of soyhulls as a replacement for corn grain. J. Dairy Sci. 85:2890-1904. Ipharraguerre, I. R., R. S. Younker, J. H. Clark, E. P. Stanisiewski, and G. F. Hartnell. 2003. Performance of lactating dairy cows fed corn as whole plant silage and grain produced from a glyphosate-tolerant hybrid (Event NK603). J. Dairy Sci. 86:1734-1741. Karnati, S. K. R., Z. Yu, J. T. Sylvester, B. A. Dehority, M. Morrison, and J. L. Firkins. 2003. Technical Note: Specific PCR amplification of protozoal 18S rDNA sequences from DNA extracted from rumen samples of cows. J. Anim. Sci. 81:812-815. Leonardi, C., and L. E. Armentano. 2003. Effect of quantity, quality and length of alfalfa hay on selective consumption by dairy cows. J. Dairy Sci. 86:557-564. McNamara, J. P. 2003. Research, improvement and application of mechanistic, biochemical, dynamic models of metabolism in lactating dairy cattle. Anim. Feed Sci. Technol. (In Press). Meyer, M. J., J. F. Smith, J. P. Harner, III, J. E. Shirley, E. C. Titgemeyer, and M. J. Brouk. 2002. Performance of lactating dairy cattle in three different cooling systems. Amer. Soc. of Agr Eng. 18(Suppl. 3):341-345. Noftsger, S. M., N. R. St-Pierre, S. K. R. Karnati, and J. L. Firkins. 2003. Effects of 2-Hydroxy-4-(methylthio) Butanoic Acid (HMB) on Microbial Growth in Continuous Culture. J. Dairy Sci. 86:2629-2636. Oba, M., R. L. Baldwin, IV, and B. J. Bequette. 2003. Oxidation of glucose, glutamate, and glutamine by isolated ovine enterocytes in vitro is decreased by presence of other metabolic fuels. J. Anim. Sci. (In Press). Phillips, G. J., T. L. Citron, J. S. Sage, K. A. Cummins, M. J. Cecava, and J. P. McNamara. 2003. Adaptations in body muscle and fat in transition dairy cattle fed differing amounts of protein and methionine hydroxy analog. J. Dairy Science 86:1354-1369. Phillips, G. J., T. L Citron, J. S. Sage, K. A. Cummins, M. J. Cecava, and J. M. McNamara. 2003. Adaptations in body muscle and fat in transition dairy cattle fed different amounts of protein and methionine hydroxy analog. J. Dairy Sci. 86:2586. Raman, P., S. S. Donkin, and M. E. Spurlock. 2003. Regulation of hepatic glucose metabolism by leptin in pig and rat primary hepatocyte cultures. Am. J. Physiol. Regul. Integr. Comp. Physiol. (In Press). Rosendo, O., M. B. Hall, C. Staples, and D. Bates. 2003. Effect de diferentes polisacaridos solubles neutron-detergent en la cinetica de digestion in vitro de la fibra neutron-detergente forrajera y en la sintesis de proteina microbiana (The effect of different neutral detergent-soluble polysaccharides on digestive kinetics in vitro of neutral detergent forage fiber and the synthesis of microbial protein). Revista Cientifica 13:18-27. Ruppert, L. D., J. K. Drackley, D. R. Bremmer, and J. H. Clark. 2003. Effects of tallow in diets based on corn silage or alfalfa silage on digestion and nutrient use by lactating dairy cows. J. Dairy Sci. 86:593-609. Schroeder, J. W. 2003. Optimizing the level of wet corn gluten feed in the diet of lactating dairy cows. J. Dairy Sci. 86:844-851. Schwab, C. G., T. P. Tylutki, R. S. Ordway, C. Sheaffer, and M. D. Stern. 2003. Characterization of proteins in feeds. J. Dairy Sci. (In Press). Silva, L. F. P., M. J. VandeHaar, M. S. Weber-Nielsen, and G. W. Smith. 2002. Evidence for a local effect of leptin on bovine mammary gland. J. Dairy Sci. 85:3277-3286. Silva, L. F. P., M. J. VandeHaar, B. K. Whitlock, R. P. Radcliff, and H. A. Tucker. 2002. Short communication: relationship of body growth to mammary development in dairy heifers. J. Dairy Sci. 85:2600-2602. Suchyta, S. P., S. Sipkovsky, R. G. Halgren, R. Kruska, M. Elftman, M. Weber-Nielson, M. J. Vandehaar, and P. M. Coussens. 2003. Bovine mammary gene expression profiling using a cDNA microarray enhanced for mammary specific transcripts. Physiological Genomics (in press). Tyler, P. A., and K.A. Cummins. 2003. Effect of dietary acsorbyl-2-phosphate on immune function of dairy heifers following transport to a rearing facility. J. Dairy Sci. 86:622. Velez, J. C. and S. S. Donkin. 2003. Bovine Somatotropin Increases Hepatic Phosphoenolpyruvate Carboxykinase mRNA in Lactating Dairy Cows. J. Dairy Sci. (Accepted). Vicini, J. L., H. G. Bateman, M. K. Bhat, J. H. Clark, R. A. Erdman, R. H. Phipps, M. E. Van Amburgh, G. F. Hartnell, R. L. Hintz, and D. L. Hard. 2003. Effect of feeding supplemental fibrolytic enzymes or soluble sugars with malic acid on milk production. J. Dairy Sci. 86:576-585. Wang, L., J. A. Story, K. K. Buhman, D. E. Moody and S. S. Donkin. 2003. Effects of psyllium on gene expression in rat liver: a microarray approach. FASEB J. 17:B522. Whitlock, L. A., D. J. Schingoethe, A. R. Hippen, K. F. Kalscheur, and A. A. Abu-Ghazaleh. 2003. Milk production and composition from cows fed high oil or conventional corn at two forage concentrations. J. Dairy Sci. 86:2428-2437. Ziemer, C. J., R. Sharp, M. D. Stern, M. A. Cotter, T. R. Whitehead, and D. A. Stahl. 2002. Persistence and functional impact of a microbial inoculant on native microbial community structure, nutrient digestion and fermentation characteristics in a rumen model. Syst. Appl. Microbiol. 24:416-422. Non-Refereed Publications AbuGhazaleh, A. A., D. J. Schingoethe, A. R. Hippen, and K. F. Kalscheur. 2003. Conjugated linoleic acid in milk, plasma, and ruminal contents of cows fed fish oil and fat sources that differed in saturation of 18-carbon fatty acids. Proc. 25th National Sunflower Association Research Forum, Fargo, ND. Burkitt, E. L., J. E. Shirley, W. F. Miller, M.V. Scheffel, and E.C. Titgemeyer. 2003. Effect of two new teat dip preparations on teat condition, somatic cell count, and incidence of mastitis under natural exposure. KSU Dairy Day Report of Progress. Anderson, V., R. Harrold, D. Lanblom, G. Lardy, B. Schatz, and J.W. Schroeder. 2003. A guide to feeding field peas to livestock: nutrient content and feeding recommendations for beef, dairy, sheep, swine and poultry. NDSU Extension Service Circ. AS-1224. Donkin, S. S., and H. M. Hammon. 2003. Hepatic gluconeogenesis in developing ruminants. D.G. Burrin and H.J. Mersmann (ed.). In Biology of Metabolism in Growing Animals. Elsevier, Amsterdam. (In press). El-Kadi, S. W., N. E. Sunny, S. L. Owens, and B. J. Bequette. 2003. Glucose metabolism by the gastrointestinal tract of sheep as affected by protein supply. Pages 401-404 in Proc. 9th Intl. Symp. Protein Energy Metab. Nutr. Firkins, J. L. 2003. Feeding by-products high in concentration of fiber to ruminants. Pages 85-102 in M.L. Eastridge (ed.) Proceedings of the 3rd National Symposium on Alternative Feeds for Livestock and Poultry. Kansas City, MO. Hall, M. B. 2003. Evaluacion de la repuesta del animal frente a la formulacion de una dieta mejorada (Evaluation of animal response for improved diet formulation). Pages 114-117 in Proc. XXXI Jornadas Uruguayas de Buiatria, Paysandu, Uruguay. Hall, M. B. 2003. Feeding and reading your cows: carbohydrates and manure in ration evaluation. Pages 9-15 in Proc. Tri-State Northwest Dairy Shortcourse, Pasco, WA. Hall, M. B. 2003. Formulacion de raciones de lecheria con carbohidratos para produccion y sanidad (Formulation of diets for dairy cows with carbohydrates for production and health). Pages 109-113 in Proc. XXXI Jornadas Uruguayas de Buiatria, Paysandu, Uruguay. Hall, M. B. 2003. Formulating for carbohydrates: from the ration to evaluation. Pages in 137-146 Proc. California Animal Nutrition Conference, Fresno, CA. Hall, M. B. 2003. Making sense of nonfibre carbohydrates in dairy rations. Pages 81-89 in Proc. 24th Western Nutrition Conference, Winnipeg, Manitoba, Canada. . Hall, M. B. 2003. Nonfiber carbohydrates in forages. Pages 53-58 in Proc. 4-State Forage Conference (MWPS-4SD15), Baraboo, WI. Hall, M. B. 2003. What you feed versus what you get: feed efficiency as an evaluation tool. Pages 24-30 in Proc. 14th Annual Florida Ruminant Nutrition Symposium, Gainesville, FL. Hall, M. B. 2003. Working with non-fiber carbohydrates in high producing dairy rations. Paper C in Proc. Colorado Dairy Nutrition Conference, Greeley, CO. Ipharraguerre, I. R., Z. Shabi, J. H. Clark, and D. E. Freeman. 2003. Use of soyhulls as an energy source for lactating dairy cows. Pages 9-12 in Illinois Dairy Report. Ipharraguerre, I. R., R. S. Younker, J. H. Clark, E. P. Stanisiewski, and G. F. Hartnell. 2003. Roundup-tolerant corn for dairy cows. Pages 13-15 in Illinois Dairy Report. Ishler, V. and G. A. Varga. 2003. Excess nitrogen affects both air and water quality. Hoards Dairyman, April 10th, p 282. Marx G.D., and J.W. Schroeder. Grow your own protein: Field peas for dairy animals. Proc. Minnesota Dairy Days, January 1-18, 2002. College of Ag., Food and Env. Sci. Univ. of Minn., St. Paul, MN. McNamara, J. P. 2003. A brief history, present research and future of metabolic models of farm animals. Pages 99-112 in Progress in Research on Energy and Protein Metabolism. EAAP Publication No.109. Miller, W. F., J. E. Shirley, E. C. Titgemeyer, A. F. Park, M.V. Burgos, A. K. Hammond, and M.V. Scheffel. 2003. Comparison of Three Fresh Cow Feeding Programs. KSU Dairy Day Report of Progress. Schwab, C. G. 2003. The latest on amino acid feeding. Pages 27-42 in Proc. Southwest Nutrition and Management Conf. Dallas, TX. Schwab, C. G., and R. S. Ordway. 2003. Methionine supplementation options. Pages 93-98 in Proc. Four-State Applied Nutrition and Management Conf. Baraboo, WI. Schwab, C. G., R. S. Ordway, and N. L. Whitehouse. 2003. Amino acid balancing in the context of MP and RUP requirements. Pages 25-34 in Proc. Four-State Applied Nutrition and Management Conf. Baraboo, WI. Schroeder, J.W. 2003. Distillers grains for dairy cattle. NDSU Extension Service Circular AS-1241. Schroeder, J.W. 2003. Field peas in dairy cattle diets. Pages 11-16 in Feeding Field Peas to Livestock. NDSU Extension Service Bull. EB-76. Shirley, J. E. 2003. Transition Cow Nutrition and Management. KSU Dairy Day Report of Progress. Stevenson, J. F, and J. E. Shirley. 2003. Increasing milking frequency in fresh cows: milk characteristics and reproductive performance. KSU Dairy Day Report of Progress. VandeHaar, M. J. 2003. Stewardship: The measure of a good farmer. Mich. Dairy Review 8(4):1-3. VandeHaar, M. J., and L. F. P. Silva. 2002. Optimal growth of dairy replacements. Pages 1-12 in Proc. CA Chapter of Am. Reg. Prof. Animal Scientists Cont. Educ. Conf., Coalinga, CA. Varga, G. A. 2003. Do we need two close up dry cow groups? Adv. Dairy Tech. 15:331-346. Varga, G. A. 2003. Feeding various carbohydrate sources to dairy cattle and effects on performance and health. University of Uppsala, Sweden. Swedish Dairy Nutrition and Feeding Conference, Kalmar, Sweden. Varga, G. A. 2003. Nutrition and management determine dairy cow productivity. Feedstuffs, March 10, pp 10-13. Varga, G. A. 2003. Practical ration evaluation: Things to look for if your nutritionist is doing a good job. Adv. Dairy Technol. 15:215-226. Varga, G. A. 2003. Soluble carbohydrates for lactating dairy cattle. Page 59-74 in Proc. 2003 Tri-State Dairy Nutrition Conference. Fort Wayne, IN. Varga, G. A., R. Ordway, M. Pickett and V. Ishler. 2003. Cows did well on a one-group dry cow feeding program. Hoards Dairyman, January 10th, p. 25. Scientific Abstracts AbuGhazaleh, A. A., D. J. Schingoethe, A. R. Hippen, and K. F. Kalscheur. 2003. Conjugated linoleic acid and transvaccenic acid content of milk from cows fed fish meal and extruded soybeans for an extended period of time. J. Dairy Sci. 86(Suppl. 1): 218. AbuGhazaleh, A., D. Schingoethe, A. Hippen, and K. Kalscheur. 2003. Rumen, plasma, and milk conjugated linoleic acid and transvaccenic acid response to fish oil supplementation of diets differing in fatty acid profile. ADSA Midwest Section, p. 71. Arieli, A., J. E. Vallimont, S. S, Donkin, and G. A. Varga. 2003. Effects of growth hormone on adipose tissue lipogenesis in transition cows. Eur. Assoc. Anim. Prod. September, Germany. Burhans, W.S., A.W. Bell, R. Nadeau and J. R. Knapp. 2003. Factors associated with transition cow ketosis incidence in selected New England herds. J. Dairy Sci. 86:247. Chichlowski, M., J. W. Schroeder, C. S. Park, W. L. Keller, and D. E. Schimek. 2003. Effect of ground canola on milk fat composition and milk yield of lactating dairy cattle. J. Dairy Sci. 86(Suppl. 1):339. Crawford, G. I., M. D. Stern, R. L. K. Hulbert and P. A. Summer. 2003. Effects of a liquid byproduct N source on fermentation by ruminal microbes in continuous culture fermenters. Conference on Gastrointestinal Function. p. 33. Cummins, K. A., and D. R. Mulvaney. 2003. Leucine metabolism in skeletal muscle of lactating dairy cows. J. Dairy Sci. 86(Suppl. 1):225. Daniels, K. J., J. R. Townsend, S. S. Donkin, S. D. Eicher, A. G. Fahey and M. M. Schutz. 2003. The effect of prepartum milking on the health and well being of first calf heifers. J. Anim. Sci. 81(Suppl 2):49. Daniels K. J., J. R. Townsend, S. S. Donkin, E. A. Pajor, A. G. Fahey, and M. M. Schutz. 2003. Behaviors of transition dairy cows and heifers. J. Dairy Sci. 86(Suppl 1):352. DeFrain, J. M., A. R. Hippen, K. F. Kalscheur, and P. W. Jardon. 2003. Feeding glycerol to transition dairy cows: Effects on dry matter intake, milk production, and blood metabolites. J. Dairy Science 86(Suppl. 1):104. DeFrain, J.M., A. R. Hippen, K. F. Kalscheur, and D. J. Schingoethe. 2003. Lactose in dairy cow diets increases ruminal butyrate proportions resulting in an increase plasma ß-hydroxybutyrate in late lactation. J. Dairy Sci. 86:(Suppl. 1):104. Dhiman, T. R., M. S. Zaman, and N. D. Luchini. 2003. Response of pre-partum and early lactation dairy cows to dietary inclusion of ruminally inert conjugated linoleic acid. J. Dairy Sci. 86(Suppl. 1):275. Etchebarne, B. E., L. F. P. Silva, G. J. M. Rosa, P. M. Coussens, M. S. Weber Nielsen, and M. J. VandeHaar. 2003. IGF-I infusion alters the gene expression profile of prepubertal bovine mammary parenchyma. J. Dairy Sci. 86(Suppl. 1):165. Etchebarne, B. E., L. F. P. Silva, G. J. M. Rosa, P. M. Coussens, M. S. Weber Nielsen, and M. J. VandeHaar. 2003. Leptin intramammary infusion alters the gene expression profile of prepubertal bovine mammary parenchyma. J. Dairy Sci. 86(Suppl. 1):166. Etchebarne, B. E., and M. J. VandeHaar. 2003. IGF binding protein-2 reduces the mitogenic effect of IGF-I, but not des-IGF-I, in MAC-T bovine mammary epithelial cells. J. Dairy Sci. 86(Suppl. 1):308. Forrest, J. W., R. M. Akers, R. E. Pearson, E. G. Brown, M. J. VandeHaar, and M. S. Weber Nielsen. 2003. Effects of varying energy intakes on estrogen receptor, cell proliferation, and tissue composition in mammary tissue of pre-pubertal heifers. J. Dairy Sci. 86(Suppl. 1):118. Forrest, J. W., R. M. Akers, R. E. Pearson, E. G. Brown, M. J. VandeHaar, and M. S. Weber Nielsen. 2003. Effects of varying energy intakes on the deposition of type IV collagen (Col IV) and fibronectin (FN) in the mammary tissue of pre-pubertal heifers. J. Dairy Sci. 86(Suppl. 1):300. Hammon, H. M., J. W. Blum, and S. S. Donkin. 2003. Effects of dexamethasone (DEXA) and growth hormone (ST) on glucose production in calves. J. Dairy Sci. 86(Suppl 1):310. Hammon H. M., H. Sauerwein, J. W. Blum, and S. S. Donkin. 2003. The response of the somatotropic axis to growth hormone (ST) and dexamethasone (DEXA) in calves. J. Dairy Sci. 86(Suppl 1):310 Hammond, A., J. E. Shirley, M. V. Scheffel, E. C. Titgemeyer, and J. S. Stevenson. 2003. Performance of dairy heifers fed high forage diets supplemented with bambermycins, lasalocid, or monensin. ADSA Midwest Section, p. 278. Holtshausen, L., and M. B. Hall. 2003. Effect of N-source on in vitro microbial crude protein and glycogen yields and NDF digestion from NDF and sucrose fermentations. J. Dairy Sci. 86(Suppl. 1):268. Khanal, R. C., T. R. Dhiman, and R. L. Boman. 2003. Influence of turning cows out to the pasture on fatty acid profile of milk. J. Dairy Sci. 86(Suppl. 1):356. Larson, C. C., and M. B. Hall. 2003. Effects of nonfiber carbohydrate sources and protein degradability on lactation performance and ruminal pH of Holstein cows. J. Dairy Sci. 86(Suppl. 1):278. Lima, M.L.M., J. L. Firkins, J. T. Sylvester, S.K.R. Karnati, and W. Mattos. 2003. Physical Effectiveness of whole cottonseed as affected by lint and particle size. J. Dairy Sci. 86(Suppl. 1):64. Lin, J.C., B. R. Moss, K. A. Cummins, P. J. Tyler, W. H. McElhenny, and C. W. Wood. 2003. Effect of alum applications on the environment of dairy calf hutches. J. Dairy Sci. 86(Suppl. 1):281. Linke, P. L., A. R. Hippen, J. M. DeFrain, D. J. Schingoethe, and K. F. Kalscheur. 2003. Ruminally protected fructose improves carbohydrate status in early postpartum dairy cows. ADSA Midwest Section, p. 79. Luimes, P. H., E. H. Beaupré, J. H. White, W. E. Weber, L. A. Hansen, H. Chester-Jones and B. A. Crooker and J. R. Knapp. 2003. Evaluation of prolactin receptor mRNA levels at different days pre and postpartum in liver tissue of genetically selected dairy cattle. J. Dairy Sci. 86(Suppl. 1):118. Markantontanos, X., J. W. Young, R. Tucker, L. F. Richardson, and G. A. Varga. 2003. Methodology for estimation of volatile fatty acids kinetics in cattle. J. Dairy Sci. 86(Suppl. 1):226. Miller, W. F., J. E. Shirley, E. C. Titgemeyer, M. J. Brouk, and M.V. Scheffel. 2003. Comparative value of full-fat corn germ, whole cottonseed, and tallow as energy sources for lactating dairy cows. ADSA Midwest Section, p. 340. Miller, W. F., J. E. Shirley, E. C. Titgemeyer, A. F. Park, A. K. Hammond, M.V. Burgos, and M. V. Scheffel. 2003. Comparison of three fresh cow feeding programs. J. Dairy Sci. 86:(Suppl 1):416. Oba, M., R. L. Baldwin, IV., and B. J. Bequette. 2003. Oxidation of glucose, glutamine and glutamate by isolated ovine enterocytes in vitro is decreased by presence of other metabolic fuels. J. Anim. Sci. 81(Suppl. 1):226. Oba, M., R. L. Baldwin, IV., S. L. Owens, and B. J. Bequette. 2003. Urea synthesis by rumen epithelial and duodenal mucosal cells isolated from growing sheep. J. Anim. Sci. 80(Suppl. 1): 59. Oba, M., R. L. Baldwin, IV., S. L. Owens, and B. J. Bequette. 2003. Utilization of [15N]ammonia for amino acid and urea synthesis by rumen epithelial and duodenal mucosal cells isolated from growing sheep. J. Anim. Sci. 81(Suppl. 1):280. Oliver, C., M. L. Bauer, J. W. Schroeder, W. L. Keller, and C. S. Park. 2002. Dietary nucleotides enhance calf immune function. FASEB J. 16(5):A985. Pickett, M. M., T. Cassidy, P. R. Tozer, and G.A. Varga. 2003. Effect of prepartum dietary carbohydrate source and monensin on dry matter intake, milk production and blood metabolites of transition dairy cows. J. Dairy Sci. 86(Suppl. 1):10. Pickett, M., T. Cassidy, and G. A. Varga. 2002. Effect of various zeolites on nutrient utilization by ruminal microorganisms during continuous culture fermentation. J. Dairy Sci. 85(Suppl. 1):230. Porter, S. F., T. R. Dhiman, D. P. Cornforth, R. D. Wiedmeier, K. C. Olson, and B. R. Bowman. 2003. Conjugated linoleic acid in tissues from beef cattle fed different lipid supplements. J. Anim. Sci. 81(Suppl. 1):110. Ribeiro, C. V. D. M., M. L. Eastridge, and D. L. Palmquist. 2003. Evaluation of the profile of fatty acids extracted from fresh alfalfa. J. Dairy Sci. 86(Suppl. 1):285. Shirley, J. E. 2003. Ruminal response to diet and dry matter intake changes during the transition period. ADSA Midwest Section, p. 45. Silva, L. F. P., J. S. Liesman, M. S. Weber Nielsen, and M. J. VandeHaar. 2003. Intramammary infusion of leptin decreases proliferation of mammary epithelial cells in prepubertal heifers. J. Dairy Sci. 86(Suppl. 1):166. Springer, H., G. A. Varga, M. M. Pickett, J. P. Goff, J. R. Stabel, and T. W. Cassidy. 2003. Effect of prepartum dietary carbohydrate source and monensin on postpartum immune function. J. Dairy Sci. 86(Suppl. 1):173. Suedekum, K. H., M. B. Hall, and M. Paschke-Beese. 2003. Comparison of different starch analysis methods for feedstuffs. J. Dairy Sci. 86(Suppl. 1):151. Sylvester, J. T., J. L. Firkins, and M. Morrison. 2003. Advancements towards the verification of a molecular-based assay to predict flow and rumen pool size of protozoal nitrogen. Conference on Gastrointestinal Function. p. 27. Sylvester, J. T., S. K. R. Karnati, M. L. M. Lima, J. L. Firkins, Z. Yu and M. Morrison. 2003. Measuring ruminal pool size and duodenal flow of protozoal N using real-time PCR. J. Dairy Sci. 86(Suppl. 1):170. Williams, E. L., F. Lundy, and G. A. Varga. 2002. The effect of zeolites on fecal ammonia concentrations. J. Dairy Sci. 85(Suppl. 1):1632. Williams, E. L., M.M. Pickett, L. C. Griel, Jr., K. S. Heyler, G. A. Varga, and S. S. Donkin. 2003. Effects of prepartum dietary carbohydrate source and monensin on expression of gluconeogenic enzymes in liver of transition dairy cows. J. Dairy Sci. 86(Suppl. 1):222.

Impact Statements

Establishment of the Ruminant Feed Analysis Consortium (NH plus other participants, supported by funds from industry partners) with the overall goal to better account for variability in nutrient composition and digestion kinetics of various feeds.
Breakout discussion sections fostered future collaborative research on all three objectives
Original research plus an update presented at the meeting (IN and VT) demonstrated the tremendous potential of DNA microarrays to quantitatively describe changes in gene expression for dairy cattle
Progress was made to improve the analysis and better characterize the feeding properties of various sugars that are being fed to dairy cattle
An amino acid subsystem describing gut viscera was developed and simulation analyses performed to improve the quantitative accuracy of Molly.
We have improved methods to reduce the incidence of ketosis in cows in early lactation
We have improved our ability to increase the amount of conjugated linoleic acid passage to the duodenum; this metabolite is an extremely potent anti-cancer agent that is naturally found in highest quantities in milk fat
We outlined a proposal for a symposium at the 2005 annual meeting of the American Dairy Science Association, Exploring the Boundaries of Efficiency in Lactation: NC-1009 Metabolic Relationships in Supply of Nutrients in Lactating Cows.

Date of Annual Report: 08/08/2005

Report Information

Annual Meeting Dates: 10/25/2004 - 10/26/2004
Period the Report Covers: 10/01/2004 - 09/01/2005

Participants

Participants Attachment:

Attachment

Brief Summary of Minutes

Minutes Attachment:

Attachment

Accomplishments

Objective 1 To quantify properties of feeds that determine the availability of nutrients critical to milk production. Procedures for study of rumen micro-organisms and processes were elaborated by two groups. MN researchers compared in sacco with in vitro procedures for determination of protein degradation and digestion. OH researchers discussed alterations in continuous in vitro rumen culture systems to enhance the retention of protozoa, new findings on protozoal mass that challenges older data, and issues with fecal analyses in N balance studies. Three groups investigated dietary and microbial protein metabolism. NH researchers extended prior work by VT researchers on urea supplementation, showing that microbial protein flow was increased quadratically with increasing dietary urea. LA and IL researchers presented non-linear predictions of rumen-undegradable protein. A substantial amount of research is being conducted on the use of byproducts in dairy cattle feeding. WI researchers varied dried distillers grains with solubles from 0 to 15% of intake and found that milk and milk protein yields increased while milk fat yield declined. KS researchers presented lactation performance data from cows fed wet corn gluten feed at 35-40% of intake. ND researchers examined the characteristics and feeding of canola and flaxseed. The impact of rumen carbohydrate metabolism was pursued by two groups. WI researchers presented data showing that omasal infusion of pectin resulted in an apparent stimulation of microbial growth in the hindgut, and potentially reduced rumen ammonia levels. The interactions between non-fiber carbohydrates (NFC) and rumen-degradable protein were investigated by USDA researchers. They also conducted experiments to differentiate the effects of different NFC sources. UT researchers continued their research on the enhancement of conjugated linoleic acids (CLA) in milk. Consumer acceptance of high CLA cheese was comparable to that of cheese with lower CLA content. Transition of cows to grazing requires more than 21 days to maximize CLA contents, but after returning to confinement feeding, CLA content decline to baseline within 8 days. These researchers also showed that rumen protection of fatty acids by calcium salts declines as chain length increases, with fatty acids greater than 22 carbons in length are fully dissociated. Objective 2 To quantify metabolic interactions among nutrients that alter synthesis of milk. MD researches presented data on amino acid use by the mesenteric- and portal-drained viscera that showed that use of essential amino acids occurs mostly in the fore-stomachs, pancreas, spleen, and omental fat, not the small intestine. They also presented data on urea recycling and use in the gastrointestinal tract that demonstrated that urea entry is tightly related to plasma urea concentration. Lastly, they showed results on galactose synthesis in mammary that challenges current dogma that all galactose is derived from blood glucose. VT researchers elaborated on amino acid transport in enterocytes in vitro, focusing on the transport of neutral amino acids through the L and A systems. MI researchers demonstrated that less mammary parenchyma at puberty correlates with lower subsequent milk yield in the first lactation. They also gave an update on the status of the gene expression arrays being produced through the National Bovine Functional Genomics Consortium. IA researchers presented further research on liver metabolism, showing a reduction in liver lipid accumulation with glucagon treatment. IN researchers had corroborative data on glucagon action, illustrating that the expression of specific enzymes was up-regulated following hormone treatment or treatment with monensin while others were unchanged. Further investigations from this group have shown that regulation of pyruvate carboxylase occurs by expression of different splice variants. Dietary manipulation of serum glucose, non-esterified fatty acids, and ²-hydroxybutyrate were conducted by SD researchers by feeding glycerol, drenching glycerol, or feeding lactose. Objective 3 To use these quantitative relationships to challenge and refine computer-based nutrition systems for dairy cattle. WA researchers utilized several data sets to demonstrate that understanding of adipose tissue metabolism as captured in the equations in the Molly model are correct. Thus, excess body weight gain in model is due to excess absorption of nutrients and incorrect estimates of basal energy use. Correction of energy use in viscera using observations of OH researchers (Reynolds et al.) provides partial improvement. The LOL researcher presented an update on the rumen model, identifying gaps in existing knowledge and understanding. CA researchers discussed the concept and use non-integral values for conversion of NADH and FADH to ATP. Implementing this concept resulted in dramatic changes in several metabolic functions including weight gain. Further discussion involved whether the original estimates were self-correcting.

Publications

Publications Attachment:

Attachment

Impact Statements

Plans for the symposium at the 2005 ADSA/ASAS Annual Meeting entitled, Exploring the Boundaries of Efficiency in Lactation: NC-1009 Metabolic Relationships in Supply of Nutrients in Lactating Cows, were finalized:
The Ruminant Feed Analysis Consortium (NH plus other participants, supported by funds from industry partners) is making good progress.
Breakout discussion sections fostered future collaborative research on all three objectives. Plans for FY05 include:
The members of this committee continue to have a tremendous impact on the field of dairy nutrition and metabolism, both as individuals and as a group. The impact within the field nationally and internationally is evidenced by: the number of peer-reviewed articles and book chapters; continued training of the next generation of dairy research scientists as indicated by the number of theses and dissertations; and the number of outreach/extension presentations and publications in this report.

Date of Annual Report: 12/16/2005

Report Information

Annual Meeting Dates: 10/24/2005 - 10/25/2005
Period the Report Covers: 10/01/2004 - 09/01/2005

Participants

Attendance:
Dr. David Benfield (North Central Region Administrative Advisor), Dr. Gary Cromwell, (CSREES Representative), Dr. Gale Bateman (Akey), Dr. Keith Cummins (AL), Dr. Joanne Knapp (J.D. Heiskell & Co.), Dr. Donald Beitz (IA), Dr. Shawn Donkin (IN), Dr. Mike VandeHaar (MI), Dr. Jeffrey Firkins (OH), Dr. Gabriella Varga (PA), Dr. Arnold Hippen (Secretary, SD), Dr. Tilak Dhiman (UT), Dr. Mark Hanigan (Chair, VA), Dr. John McNamara (WA), Dr. Louis Armentano (WI)

Absent:

Dr. Donato Romagnolo (AZ), Dr. James Fadel (CA), Dr. Alex Hristov (ID), Dr. Jimmy Clark (IL), Dr. John Shirley (KS), Dr. Kyle McLeod (KY), Dr. Brian Bequette (MD), Dr. Brian Crooker (MN), Dr. Marshall Stern (MN), Dr. Ronald Belyea (MO), Dr. C. S. Park (ND), Dr. Marc Baur (ND), Dr. J.W. Schroeder (ND), Dr. Chuck Schwab (NH), Dr. Mary Beth Hall (USDA-ARS), Larry Satter (USDA-ARS)

Participants Attachment:

Attachment

Brief Summary of Minutes

DAY 1

Chair, Mark Hanigan opened the meeting and introductions were made.

Remarks by Dr. David Benfield
Dr. Benfield described intent and use of newly required Annual Impact Statements. Reminded committee that project expires in 2007 and that we need writing committee assigned at this meeting.

Remarks by Dr. Gary Cromwell
Dr. Cromwell introduced himself and presented a report from CSREES, describing the organizational structure, proposed budgets, and anticipated release dates for future NRC publications. Dr. Cromwell led a brief discussion regarding cost and value of NRC publications to industry.

Station Reports addressing Objective 1 were presented by:
1. Dr. Lou Armentano (University of Wisconsin)
2. Dr. Jeff Firkins (Ohio State University)
3. Dr. Gabriella Varga (Pennsylvania State University)
4. Dr. Tilak Dhiman (Utah State University)
5. Dr. Arnold Hippen (South Dakota State University)

Station Reports addressing Objective 2 were presented by:
1. Dr. Keith Cummins (University of Alabama)
2. Dr. Shawn Donkin (Purdue University)
3. Dr. Don Beitz (Iowa State University)
4. Dr. Mike VandeHaar (Michigan State University)

Discussion followed the presentation of each station report.

The first day of discussion was closed with an open discussion led by Lou Armentano (WI) on potential collaborative research regarding determination and reporting of particle size of experimental diets.

DAY 2

Station Reports addressing Objective 3 were presented by:
1. Dr. Joanne Knapp (University of Vermont)
2. Dr. Gale Bateman (Akey)
3. Dr. Mark Hanigan (Virginia Tech)
4. Dr. John McNamara (Washington State University)

Discussion followed the presentation of each station report.

Dr. David Benfield outlined timetable for preparation of the project rewrite for 2007. Important dates follow:

9/15/06 Statement of issues and justification submitted into NIHMS

9/30/06 Submission of validation

10/15/06 Appendix E due from member

11/15/06 Approval by Experiment Station Directors

12/01/06 Full proposal submitted into NIHMS by Committee Chair

12/15/06 Last SAES 422 due

Jan-Feb 07 NCA Review by Department Heads

2/15/07 NCA Evaluation due

Feb-Apr 07 MRC Review of proposal at spring meeting

Follow-up and Other Business:
1. Dr. Lou Armentano (WI) was unanimously voted in as Secretary for FY06 to be Chair in FY07. Lou accepted nomination
2. Dr. John McNamara (WA) volunteered to lead rewrite of project for 2007. Drs. Keith Cummins (AL) and Jeff Firkens (OH) volunteered to assist with rewrite. Committee members are encouraged to provide Dr. McNamara with documentation of collaborative efforts. Dr. Benfield recommendation impact statements to specifically address impact of research on the discipline and reinforced the need to highlight collaborative efforts.
3. Next years meeting to be held October 30 and 31 in Sioux Falls, SD arranged by Dr. Arnold Hippen (Chair 06; South Dakota State University).
4. Members were reminded to submit an electronic copy of this year's report to Committee Chair, Dr. Mark Hanigan (VA).
5. The meeting closed with appreciation to Dr. Hanigan for his service as Committee Chair for the past year.

Chair Hanigan concluded and adjourned the meeting.

Minutes Attachment:

Attachment

Accomplishments

Objective 1 To quantify properties of feeds that determine the availability of nutrients critical to milk production. Major findings under Objective 1 during 2005 include: The results of work at Utah suggest that conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA) contents of milk from cows fed fresh green chopped alfalfa forage can be enhanced up to 60% by feeding 475 g/d of linseed oil plus menhaden fish oil at a 65:35 ratio without any negative effects on feed intake, milk yield or milk composition. Feeding 2.1% of the diet as calcium salts of unsaturated fatty acids had a similar affect on CLA and TVA contents. Inclusion of ground canola seed in the diet was found to be linearly associated with increased duodenal flow (g/d) of stearic acid (C18:0), the cis-9, cis-12, cis-15 C18:3 isomer of linolenic acid, total linolenic acid, long-chain, monounsaturated, total omega-3, and total fatty acids (ND). Ileal flow of stearic acid, trans-9 C18:1 (oleic acid), cis-6, cis-9, cis-12 C18:3 (linolenic acid), total C18:3, long-chain, monounsaturated, saturated, and total fatty acids were linearly increased by the addition of canola to the diet. Ileal flow of the cis-9, trans-11 and trans-10, cis-12 isomers of CLA were unaffected by diet. However, CLA flow at the ileum was greater than at the duodenum. The cis-9, trans-11 isomer was not present in duodenal digesta, but it was present in ileal digesta in small amounts. It was observed that glycerol from soy biodiesel production may be fed at up to 2 kg/d to lactating dairy cows (SD). Effects on production are few, though increased feed efficiency may result for the energy content of glycerol used to support milk production. Drying distillers grains with solubles (DGS) marginally increased ruminally undegraded DM and markedly increased RUP. Drying DGS, however, does decrease the concentration of Lys in the CP fraction post-ruminally. Feeding wet distillers grains at 15% of diet DM for 12 wk did not have any significant impact on health, production, or composition of milk. Though milk protein was not effected by WDG, concentrations of MUN were increased by feeding WDG. It was observed that for corn silage and alfalfa haylage, the percent of DM above the 9 mm screen is very highly correlated with the mean particle size (WI). The same holds true for TMR, although the regression is different than it is for forages. The next smaller screen size (5.4 mm diagonal) also had a strong relationship. The strength of the relationship fell off for longer and shorter screens. This analysis suggests that a single medium sized screen could be used to get a reasonable estimate of physical effectiveness. Work at USDA-DFRC was conducted to evaluate possible in vitro culture technique improvements for evaluation of NDF digestion. The work may offer a method of more easily assessing NDF disappearance and progress of the fermentation of ND-soluble carbohydrates in the same vessel. Interactions of hay type and grain processing were assessed at Pennsylvania. Dry matter intake (DMI) was lower for cows fed grass hay diets (20 vs. 23 kg/d), while amount of NDF consumed did not differ across diets. Milk yield (37.2 ± 1.37 kg/d) and fat corrected milk yield (FCM; 36.7 ± 3.3 kg/d) did not differ. Dry matter efficiency (FCM/DMI) was higher (P =0.08) for cows fed grass hay vs. grass silage diets (1.92 vs. 1.54). Numerical trends showed lower milk fat, protein and lactose percentages and yields for cows provided grass silage vs. grass hay diets. DM digestibility was higher for grass silage diets (54.7 vs. 48.4%), however no differences were observed for NDF digestibility across diets (37.8% ± 3.36). Fecal output (% DM basis) was highest for the grass hay diet with coarse corn compared to the other three diets (13.8 vs. 9.85 kg/d). Numerical trends were observed for ruminal contents such that cows provided the grass silage diets had greater amounts of ruminal digesta than cows provided grass hay diets (90.4 vs. 75.6 kg). Propionic acid concentration was higher for cows provided diets containing fine ground corn vs. cracked corn. Higher concentrations of total VFA and isoacids were observed for diets containing grass silage vs. grass hay diets. Following from earlier work (WI), abomasal infusion of inulin did not significantly affect intake of N, milk N, or N balance, but inulin significantly increased fecal N by 23 g/d and decreased urinary N by 24 g/d. These results suggest that manipulating dairy diets to increase hindgut fermentation and reduce manure ammonia volatilization should not reduce N recycling to the rumen for microbial protein production. However, inulin did decrease nutrient digestibility and milk fat yield, indicating that hindgut fermentation or small intestinal passage of soluble fiber may negatively impact production potential. Work at Illinois suggests that partially replacing solvent extracted soybean meal (SBM) with extruded SBM, non-enzymatically browned SBM, or whole roasted soybeans may increase the quantity of feed protein that reaches the small intestines of dairy cows. However, significant improvements in the supply of previously reported limiting amino acids for milk production, particularly of Met, should not be expected. Supplementation of diets for non-lactating cows with DL- Methionine and L-Lysine hydrochloride resulted in no effects on ruminal VFA concentrations or proportions, or ruminal pH. Ruminal NH4+N concentrations were low (average 2.9 mg/dL) and may be an indication that ruminal N availability was limiting in the experiment (LA). Feeding Met as dl-Met, 2-hydroxy-4-methylthiobutanoic acid (HMB), or as the isopropyl derivative of HMB appeared to alter ruminal bacterial but not protozoal populations (OH). There appears to be minimal selective retention of protozoal genera between the rumen and omasum (i.e., the reticulum) in dairy cattle, supporting the use of omasal sampling for assessing microbial populations (OH). However protozoal numbers in omasal samples were found to be significantly greater than for ruminal samples. Preliminary efforts to grow protozoa in continuous culture indicate that diverse species (including isotrichids) can be repeatedly maintained by decreasing the feeding, fluid dilution, and stirring rates and by substituting a 50-¼m filter (including prefilters to prevent clogging, which occurred with 10-¼m filters) instead of the 250-¼m standard filter such that all except the very small protozoa pass only with the overflow port (OH). Objective 2 To quantify metabolic interactions among nutrients that alter synthesis of milk. Major findings under Objective 2 during 2005 include: Chromium supplementation was associated with increased basal glucose and decreased basal insulin and non-esterified fatty acids (NEFA) in serum in a dose-dependent, quadratic manner (WA). Chromium increased glucose clearance rate as measured by half-life, time to nadir and area under the curve. Insulin concentrations tended to be lower in treated animals while clearance rates were unchanged. Serum NEFA were negatively correlated with glucose, such that treated animals with increased glucose had lower NEFA overall. This study helps to confirm biological activity of supplementation of chromium in dairy animals. Supplementation with rumen protected choline (RPC) or dry propylene glycol (PG) did not significantly affect DMI, MY, milk composition, BCS, body weights or blood glucose concentrations in either the prepartum or postpartum period (PA). Calf birth weights were also not affected by treatments. Based on results obtained in the present study, neither RPC nor dry PG appeared to affect intake, blood glucose concentration or production responses of multiparous periparturient Holstein dairy cows. In a second dose-response study, RPC appeared to have dose-dependent effects on reducing NEFA with 11% and 23 % reduction for cows provided 25 g and 50 g RPC vs. control, respectively. It was observed that glucagon, glycerol, and glucagon plus glycerol increases plasma glucose and decreases NEFA on a short-term basis, but not rates of gluconeogenesis and lipolysis. TNF-a does not alter rates of gluconeogenesis or lipolysis on short-term basis (IA). A study was begun at Alabama to assess changes in the muscle proteome associated with the onset of lactation. Muscle biopsies were being taken at -10 and + 4 days of lactation. 2-D gel electrophoresis has been used to visualize the proteins before and after the onset of lactation. Results so far indicate changes in muscle proteome with onset of lactation. Identification of the proteins has not begun. Studies were conducted at Maryland with ruminal and intestinal cells from beef cattle to determine the influence of feeding a low (25:75, n=6) or high (75:25, n=6) forage ration on 1) contributions of volatile fatty acids, glucose, and amino acids to oxidative metabolism and 2) the relative expressions of a number of metabolism related genes in tissues comprising the viscera. It was observed that high energy diets fed to prepubertal heifers for longer durations result in a linear increase in leptin concentrations in serum and mammary tissue and leptin expression in mammary tissue (MI). Similar results were obtained with mammary tissue from heifers fed for 1200 vs 800 g/d from 4 months to puberty. These data are consistent with the idea that leptin may mediate the negative effects of high energy diets on mammary development. Thus, we speculate that increased energy intake, which increases IGF-I, a potent mitogen of muscle and mammary cells, does not increase mammary growth as it increases muscle growth because leptin interferes with mammary cell proliferation. Intramammary infusions of leptin inhibited the mitogenic action of IGF-I infusions in prepubertal heifers. It was found that leptin increased expression of SOCS3 (suppressor of cytokine signaling-3) in quarters infused with IGF-I. This may explain why leptin inhibits IGF-I action. The activated leptin receptor recruits the transcription factor STAT3. This results in the tyrosine phosphorylation of STAT3 and its translocation to the nucleus. Once in the nucleus, STAT3 mediates gene transcription, including transcription of SOCS3. SOCS3 inhibits signaling by certain cytokine receptor-Jak kinase complexes, either by directly inhibiting Jak2 activity or by targeting the complex to the proteosome. When cows fed 11, 15, or 19% CP diets for 12 days, efficiency of N use increased from 27% on the high protein diet to 41% on low protein diet, but milk protein output declined by 25% on the low protein diet. Genomic DNA containing the bovine pyruvate carboxylase (PC) promoter has been cloned and the promoter identified (IN). Translational efficiency experiments coupled with observations of increased expression of the same mRNA variants with feed restriction indicate that both the profile of mRNA variants as well as overall level of PC mRNA are potential control points for lactate metabolism. Sequence data for bovine phospho-enol-pyruvate carboxy kinase (PPECK) promoter indicates the lack of homology in promoter sequence and transcription factor binding map. The latter may contribute to the lack of similarity in response to alimentary status and hormonal conditions in cattle compared with rats and other nonruminants and may provide a unique control of PEPCK expression in dairy cattle. Objective 3 To use these quantitative relationships to challenge and refine computer-based nutrition systems for dairy cattle. Major findings under Objective 3 during 2005 include: In general, the NRC model was found to be more sensitive to dietary inputs than MOLLY (LA, VA, WA, and CA). Therefore, having an accurate description of nutrient supply to use as inputs for the models is important and should be considered when evaluating predictions from those models. A meta-analysis was used to evaluate two data sets, one for nitrogen flow to the small intestine and one for performance of cows (IL). Responses of dairy cows to rumen undegradable protein supplements were variable. A portion of this variability is explained by source of CP in the control diets, the proportion and source of rumen undegradable protein in the experimental diet, the effect of rumen undegradable protein on microbial protein outflow from the rumen, the degradability and amino acid content of the rumen undegradable protein, and the crude protein percentage of the diet. Compared with soybean meal, the mean milk production responses to feeding rumen undegradable protein supplements ranged from -2.5% to +2.75%. Because of the large variation and small magnitude of response when rumen undegradable protein supplements are fed compared with soybean meal, efficiency of nitrogen utilization and the cost to benefit ratio for these crude protein supplements may determine the source and amount of crude protein to feed to dairy cows in the future. The effects of using a non-integral value of less than 3 mol ATP/mol NADH was further explored in Molly with respect to observed challenges with predictions of weight change. If ATP yields are adjusted downwards, predictions of body weight gain decline as expected (CA and WA). This would help address overpredictions of body weight gain observed when full lactation simulations are undertaken. However, the model becomes unstable likely due to the loss of internal flux balance. If this change is undertaken, the model must be reparameterized with the new ATP yield in place to bring the model back into balance. Previous formulas used to calculate protozoal generation time were based on steady state growth kinetics. Using those formulas biased generation time estimates. Consequently, regression was deemed the most appropriate way to calculate the change in generation time during adaptation to an abrupt change in transfer rate. Net protozoal generation time was calculated using protozoal count data determined at each of the transfers and calculating the cumulative cells from the 0 and 0.25-µmol/L monensin treatments. Mean cumulative cell counts were transformed to logarithm base2, because normal protozoal cell replication is completed by binary fission. Mean cell counts were regressed against day of experiment (i.e., 1, 2, or 3 d) for each transfer rate to determine the fraction of the protozoal pool generating per day. Protozoal growth curves were fit using PROC GLM of SAS. The first derivative of the regression equation provided the change in cells per day (OH). If the equation was not linear, then the slope was solved at that respective day. A change of one logarithm unit is one doubling (i.e., one generation), so the slope is the proportion of one generation per day. After converting to hours, the reciprocal was the generation time at each respective day of incubation. Molly was found to accurately predict N partition between excretion into urine, feces, and milk during short-term simulations (two weeks). The model was also able to predict the consequences of daily variation in dietary crude protein intake on milk and milk protein yield during short-term simulations (J. D. Heiskell). Molly was challenged with experimental data and found to simulate milk component production well when supplied with intake data and individual cow genetic potential (WA). The model simulates the effects of changes in feed intake well. Sensitivity analyses investigated the effects of increasing the basal costs of protein turnover in the body, the effect of increased food intake on energy expenditure in the body and the effect of increased feed intake on energy metabolism in the viscera. Increasing the energetic cost of increased feed intake in the viscera gave the most satisfactory improvement. Studies compared data collected from Reynolds et al (OH) on metabolism in viscera. These data justified alteration in the parameters that describe visceral metabolism in the model. Increase in energy use in the viscera improved accuracy of body fat use without compromising accuracy of milk component prediction. Inclusions of equations on ketosis and butyrate use were added to the model to more accurately reflect carbon use in early lactation. Protein turnover in the lactating goat was estimated from isotope kinetics and found to be greater than 200%/d as compared to the assumed turnover of 8%/d in Molly (VA and MD). If adopted, such a change in turnover would result in significant increases in predictions of energy expenditure associated with mammary maintenance. A method to consider fixed trial effects for complex nonlinear models was developed and tested with a small nonlinear gravid uterus model (VA. Additionally, this development work resulted in the externalization of the parameter estimation routines in ACSL which will allow one to make use of the matrix language provided by ACSL Math. This will be useful in developing tools to integrate micro-array and proteomic measurements with metabolism models.

Publications

Refereed publications of NC-1009 Committee members during 2005 Armentano, L. E. and Taysom, D. 2005 Short Communication: Prediction of Mean Particle Size and Proportion of Very Long Fiber Particles from Simplified Sieving Results J. Dairy Sci. 88: 3982-3985. Bateman, H. G., II, J. H. Clark, and M. R. Murphy. 2005. Development of a system to predict flow of feed protein flow to the small intestine of cattle. J. Dairy Sci. 88:282-295. Bateman, H. G., II. 2005. Response to Increased Rumen Undegradable Protein Intake by Lactating Dairy Cows. Prof. Anim. Sci. 21:263-271. Bateman, H.G., II, J.H. Clark, and M.R. Murphy. 2005. Development of a System to Predict Feed Protein Flow to the Small Intestine of Cattle. J. Dairy Sci. 88:282-295. Brown, E.G., M. J. VandeHaar, K. M. Daniels, J. S. Liesman, L. T. Chapin, D. H. Keisler*, and M. S. Weber Nielsen. 2005. Effect of increasing energy and protein intake on body growth and carcass composition of heifer calves. J Dairy Sci 88:585-594. Brown, E. G., M. J. VandeHaar, K. M. Daniels, J. S. Liesman, L. T. Chapin, J. W. Forrest, R. M. Akers, R. E. Pearson, and M. S. Weber Nielsen. 2005. Effect of increasing energy and protein intake in heifer calves on mammary development. J. Dairy Sci. 88:595-603. Chichlowski, M.W., J.W. Schroeder, C.S. Park, W.L. Keller, and D.E. Schimek. 2005. Altering the fatty acid profile in milk fat by including canola seed in the diet of dairy cattle. J. Dairy Sci. 88:3084-3094. Davis LE, Weber Nielsen MS, Chapin LT, Liesman JS, VandeHaar MJ 2004 Effects of a high rate of gain for increasing lengths of time on body and mammary growth in prepubertal dairy heifers. J Animal and Feed Sci 13(Suppl. 1):479-482. DeFrain, J. M., Hippen, A. R., Kalscheur, K. F., Jardon, P. W. 2004. Feeding glycerol to transition dairy cows: effects on blood metaboliltes and lactation performance. Journal of Dairy Science 87:4195-4206. DeFrain, J. M., Hippen, A. R., Kalscheur, K. F., Patton, R. S. 2005. Effects of feeding propionate and calcium salts of long-chain fatty acids on transition dairy cow performance. Journal of Dairy Science 88(3):983-993. Douglas, G. N., T. R. Overton, H. G. Bateman, II, and J. K. Drackley. 2004. Peripartal metabolism and production of Holstein cows fed diets supplemented with fat during the dry period. J. Dairy Sci. 87:4210-4220. Edwards, J.E., Bequette, B.J., McKain, N., McEwan, N.R., & Wallace, R.J. (2005) Influence of flavomycin on microbial numbers, microbial metabolism and gut tissue protein turnover in the digestive tract of sheep. Br. J. Nutr. 94: 6470. Etchebarne BE, Nobis W, Allen MS, VandeHaar MJ 2004. Design of a bovine metabolism oligonucleotide gene array. J Animal and Feed Sci 13(Suppl. 1):385-388. Firkins, J.L., A.N. Hristov, M.B. Hall, G.A. Varga, and N.R. St-Pierre. 2005. Integration of ruminal metabolism in dairy cattle. J. Dairy Sci. (Accepted). Gressley, T. F. and L. E. Armentano 2005 Effect of Abomasal Pectin Infusion on Digestion and Nitrogen Balance in Lactating Dairy Cows,J. Dairy Sci. 88: 4028-4044. Hammon, D. S., G. R. Holyoak, T. R. Dhiman. 2005. Association between elevated plasma urea nitrogen and elevated ammonia concentration in follicular fluid of preovulatory follicles in early lactation dairy cows. Anim. Repro. Sci. 86:195-204. Hammon, H. M., C. Philipona, Y. Zbinden, J.W. Blum, and S.S. Donkin. 2005. Effects of dexamethasone and growth hormone treatment on hepatic gluconeogenic enzymes in calves. J. Dairy Sci. 88:2107-2116. Ipharraguerre, I.R., J.H. Clark, and D.E. Freeman. 2005. Rumen Fermentation and Intestinal Supply of Nutrients in Dairy Cows Fed Rumen-Protected Soy Products. J. Dairy Sci. 88:2879-2892. Ipharraguerre, I.R., J.H. Clark, and D.E. Freeman. 2005. Varying Protein and Starch in the Diet of Dairy Cows. I. Effects on Ruminal Fermentation and Intestinal Supply of Nutrients. J. Dairy Sci. 88:2537-2555. Ipharraguerre, I.R., and J.H. Clark. 2005. Varying Protein and Starch in the Diet of Dairy Cows. II. Effects on Performance and Nitrogen Utilization for Milk Production. J. Dairy Sci. 88:2556-2570. Ipharraguerre, I.R., and J.H. Clark. 2005. Impacts of the Source and Amount of Crude Protein on the Intestinal Supply of Nitrogen Fractions and Performance of Dairy Cows. J. Dairy Sci. 88(E. Suppl.):E22-E37. Khanal, R. C., T. R. Dhiman, A. L. Ure, C. P. Brennand, R. L. Boman, and D. J. McMahon. 2005. Consumer acceptability of conjugated linoleic acid-enriched milk and Cheddar Cheese from cows grazing on pasture. J. Dairy Sci. 88:1837-1847. Leonardi, C., Bertics, S. and Armentano, L. E. 2005 Effect of Increasing Oil from Distillers Grains or Corn Oil on Lactation Performance J. Dairy Sci. 88: 2820-2827. Leonardi, C., Giannico, F., and Armentano, L. E. 2005 Effect of Water Addition on Selective Consumption (Sorting) of Dry Diets by Dairy Cattle J. Dairy Sci. 5 88: 1043-1049. Leonardi, C., Shinners, K. J., and Armentano, L. E. 2005 Effect of Different Dietary Geometric Mean Particle Length and Particle Size Distribution of Oat Silage on Feeding Behavior and Productive Performance of Dairy Cattle J. Dairy Sci. 88: 698-710. Nafikov, R.A., B.N. Ametaj, G. Bobe, K.J. Koehler, J.W. Young, and D.C. Beitz. 2005. Prevention of fatty liver in transition dairy cows by subcutaneous injections of glucagon. J. Dairy Sci. In press. Oba, M., Baldwin, R.L., IV, Owens, S.L, & Bequette, B.J. (2005) Metabolic fates of ammonia nitrogen in ruminal epithelial and dudoenal mucosal cells isolated from growing sheep. J.Dairy Sci. 88: 3963-3970. Poulson, C. S., T. R. Dhiman, A. L. Ure, D. Cornforth, and K. C. Olson. 2004. Conjugated linoleic acid content of beef from cattle fed diets containing high grain, CLA or forages. Livestock Prod. Sci. 91:117-128. Qiu, X., M.L. Eastridge, and J.L. Firkins. 2004. Effects of dry matter intake, addition of buffer, and source of fat on duodenal flow and concentration of conjugated linoleic acid and trans-11 C18:1 in milk. J. Dairy Sci. 87:4278-4286. Radcliff RP, VandeHaar MJ, Kobayashi Y, Sharma BK, Tucker HA, and Lucy MC 2004 Effect of dietary energy and somatotropin on components of the somatotropic axis in holstein heifers. J Dairy Sci 87:1229-1235. Reveneau, C., C.V. Ribeiro, M.L. Eastridge, N.R. St-Pierre, and J.L. Firkins. 2005. Processing whole cottonseed moderates fatty acid metabolism and improves performance by dairy cows. J. Dairy Sci. (In Press). Schroeder, J.W. , M.L. Bauer, and S.A. Soto-Navarro. 2005. Rumen undegradable protein and fresh versus stored wet corn gluten feed in the diets of lactating dairy cows. Prof. Anim. Sci. 21:254-262. Silva LFP, B.E. Etchbarne, J.S. Liesman, M.S. Weber Nielsen, and M.J. VandeHaar. 2005. Intramammary infusion of IGF-I increases BrdU-labeling in mammary epithelial cells of prepubertal heifers. J Dairy Sci 88:2271-2273. Sylvester, J.T., S.K.R. Karnati, Z. Yu, C.J. Newbold, and J.L. Firkins. 2005. Evaluation of a real-time PCR assay quantifying the ruminal pool size and duodenal flow of protozoal nitrogen. J. Dairy Sci. 88:2083-2095. Sylvester, J.T., S.K.R. Karnati, Z. Yu, M. Morrison, and J.L. Firkins. 2004. Development of an assay to quantify rumen ciliate protozoal biomass in cows using real-time PCR. J. Nutr. 134:3378-3384. Tozer, P. R., G. A. Varga, and W. R. Henning. 2004. Do Dairy Producers Market and Manage Dairy Cows to Improve Beef Quality? Prof. Anim. Sci (In press). Ure, A. L., T. R. Dhiman, M. D. Stern and K. C. Olson. 2005. Treated extruded soybean meal as a source of fat and protein for dairy cows. Asian-Australasian J. Anim. Sci. 18 (7):980-989. Vallimont, J. E., F. Bargo, T. W. Cassidy, N. D. Luchini, G. A. Broderick, and G. A. Varga. 2004. Effects of replacing dietary starch with sucrose on ruminal fermentation and nitrogen metabolism in continuous culture. J. Dairy Sci. 87:4221-4229 Velez, J.C. and S.S. Donkin. 2005. Feed restriction induces pyruvate carboxylase but not phosphoenolpyruvate carboxykinase in dairy cows. J. Dairy Sci. 88: 2938-2948. Williams, E.L., S.M. Rodriguez, D.C. Beitz, and S.S. Donkin. 2005. Effects of short-term glucagon administration on gluconeogenic enzymes in the liver of mid-lactation dairy cows. J. Dairy Sci. (In press). Book chapters and reviews during 2005 Bateman, H. G. 2005. Feeding and Nutrition of Dairy Cattle. Chapter 17 (pp. 420-442) of Applied Animal Nutrition: Feeds and Feeding, 3rd edition, Peter R. Cheeke, editor. Prentice-Hall, Inc. Upper Saddle River, NJ. Bequette, B.J., Sunny, N.E., El-Kadi, S.W., & Owens, S.L. (2005) Application of stable isotopes and mass isotopomer distribution analysis to the study of intermediary metabolism of nutrients. J. Anim. Sci. 88: (Suppl. 1) (Invited Review) Bobe, G., J.W. Young, and D.C. Beitz. 2004. Invited review: Pathology, etiology, prevention, and treatment of fatty liver in dairy cows. J. Dairy Sci. 87:3105-3124. Donkin, S.S. and H.M. Hammon. 2005. Hepatic gluconeogenesis in developing ruminants. In Biology of Metabolism in Growing Animals. Elsevier, Amsterdam. Edited by D.G. Burrin and H.J. Mersmann. pp. 375-390. Drackley, J.K., S.S. Donkin, and C.K. Reynolds. 2005. Invited Review. Major advances in fundamental dairy cattle nutrition. J. Dairy Sci. (In press). Firkins, J.L., and C.K. Reynolds. 2005. Whole animal nitrogen balance in cattle. E. Pfeffer and A.N. Hristov, eds. Nitrogen and Phosphorus Nutrition of Cattle and Environment (in press). Firkins, J.L. and Z. Yu. 2005. Characterisation and quantification of the microbial populations of the rumen. International Symposium on Ruminant Physiology (in press). Hanigan, M.D., H. G. Bateman, J. G. Fadel, J. P. McNamara, N.E. Smith 2005. An ingredient-based input scheme for Molly. International Workshop on Modelling Nutrient Utilization. CAB International, in press. Hanigan, M. D., H. G. Bateman, J. G. Fadel, and J. P. McNamara. 2006. Metabolic Models of Ruminant Metabolism: Recent Improvements and Current Status. J. Dairy Sci. 90. In press. Hanigan, M. D. (2005). Quantitative aspects of ruminant splanchnic metabolism as related to predicting animal performance. Anim Sci. 80:23-32. McNamara, J.P. 2005. Research, Improvement and application of mechanistic, biochemical, dynamic models: from Genetics to Kinetics. Chapter 6 In: Mathematical modeling in nutrition and Toxicology. Proceedings of the 8th International Conference on Mathematical Modeling in Nutrition and Health Science. Georgia Center for Continuing Education, pp 87-110. Mathematical Biology Press. ISBN 1-4116-2594-3. McNamara, J. P., G. J. Phillips, T. L. Citron, J. S. Sage. 2005. Challenge and improvement of a model of dairy cattle metabolism to describe changes in metabolism in cows in early lactation. International Workshop on Modelling Nutrient Utilization. Pp XX-YY in Proceedings of 6th International workshop on modeling in farm animals. CAB International, in press. VandeHaar MJ 2005 Regulation of nutrient partitioning: an overview of the hormones that are affected by nutrition or that directly alter metabolism. Pages 275-289 in Pond WG, Church DC, Pond KR, Schoknecht PA, Basic Animal Nutrition and Feeding, 5th ed., John Wiley & Sons, Inc., Hoboken, NJ. VandeHaar MJ 2005 Dairy cattle. Pages 413-437 in Pond WG, Church DC, Pond KR, Schoknecht PA, Basic Animal Nutrition and Feeding, 5th ed., John Wiley & Sons, Inc., Hoboken, NJ Non-refereed publications during 2005 Bateman, H.G., II., J.H. Clark, and M.R. Murphy. 2005. Predicting Feed Protein Flow to the Small Intestine. Illinois Dairy Report. Pp. 56-60. Beitz, D.C., J.W. Young, A.R. Hippen, and R. Nafikov. 2004. Use of glucagon to prevent and treat fatty liver in transition dairy cows. A.S. Leaflet R1903. ISU Animal Industry Report. Bobe, G., B.N. Ametaj, R.A. Nafikov, D.C. Beitz, and J.W. Young. 2004. Health and reproductive performance of lactating dairy cows with mild fatty liver receiving exogenous glucagon. A.S. Leaflet R1904. ISU Animal Industry Report. Bobe, G., V. Amin, D.C. Beitz, and J.W. Young. 2004. Non-invasive diagnosis of fatty liver and degree of fatty liver in dairy cows by digital analyses of hepatic ultrasonograms. A.S. Leaflet R1905. ISU Animal Industry Report. Clark, J.H., and I.R. Ipharraguerre. 2005. Responses to Source of Supplemental Protein. Four-State Dairy Nutrition and Management Conference. Midwest Plan Service (MWPS-45018), Iowa State University, Ames. Pages 103-112. Hall, M. B. 2005. Diagnosing & managing subclinical rumen acidosis in dairy cattle. In: Proc. 23rd Annual Forum of the American College of Veterinary Internal Medicine, June 3, 2005, Baltimore, MD. CDROM and online. Hall, M. B. 2005. What we do and don't know about forage and carbohydrate digestion in the dairy cow (and some more food for thought). In: Proc. Feed and Nutritional Management Cow College, January 11 - 12, 2005, Virginia Polytechnic Institute and State University, Blacksburg, VA. p. 1 - 12. Hall, M. B. 2005. Using manure evaluation as a diagnostic tool for ration evaluation. In: Proc. Feed and Nutritional Management Cow College, January 11 - 12, 2005, Virginia Polytechnic Institute and State University, Blacksburg, VA. p. 67 -74. Hall, M. B. 2005. The latest in carbohydrate nutrition & evaluating its impact on health and performance. In: Proc. New England Dairy Feed Conference, West Lebanon, NH. March 31, 2005. Hall, M. B. 2005. The latest in carbohydrate nutrition & evaluating its impact on health and performance. In: Proc. Ruminant Health and Nutrition Conference, Syracuse, NY March 29, 2005. Hall, M. B. 2005. Sugars in dairy cattle rations: sweetening the pot or not? In: Four-State Dairy Nutrition and Management Conference Proceedings, June 15 & 16, 2005, Dubuque, IA. p. 221 - 228. MWPS-4SD18. Ipharraguerre, I.R., J.H. Clark, and D.E. Freeman. 2005. Effects of Protein on Ruminal Fermentation, Intestinal Supply of Nutrients, and Nutrient Digestion in Dairy Cows. Illinois Dairy Reports. Pp. 35-39. Ipharraguerre, I.R., and J.H. Clark. 2005. Protein Effects on Cow Performance. Illinois Dairy Report. Pp. 44-46. Ipharraguerre, I.R., and J.H. Clark. 2005. Rumen Protected Soy Products for Dairy Cows. Illinois Dairy Report. Pp. 47-50. Schroeder, J. W. 2005. Common weights and measures for the farm. NDSU Extension Service Circular AS-1282. Schroeder, J.W., Mostrum, M., and Anderson, V.. Test DON Before Feeding Dairy Cattle - High levels in grain and straw are cause for concern. AgWeek Regional News. Vol.21, No. 5, p. 14, Monday, September 12, 2005. J.W. Schroeder. Improving Dairy Efficiency with Quality Forage. Forage Focus, Midwest Forage Newsletter, p. 2. May 2005 Schroeder, J.W. Use Caution When Feeding Dairy Cattle High Levels of Concentrate. The Progressive Dairyman, Vol. 19, No. 3, p. 10. March 2005. Schroeder, J. W.. Use Corn Silage Soon After its Moved. AgWeek. Vol. 20, No. 18, p. 14. Published by the Grand Fork Herald, December 6, 2004. Schroeder, J. W.. Storing Shelled Corn in Bags. AgWeek. Vol. 20, No.14, p.11. Published by the Grand Fork Herald, October 4, 2004. VandeHaar M. J. 2005 Developments in replacement nutrition. Proc Michigan Veterinary Conference, Jan 29, Lansing, MI, Michigan State University. Published abstracts during 2005 Bateman, H. G., II, T. W. Braud, C. C. Williams, D. T. Gantt, C. F. Hutchison, J. D. Ward, P. G. Hoyt, and G. A. Sod. 2005. Effects of supplemental DL-methionine and L-lysine HCl on ruminal fermentation and ruminal and total tract digestibility in non-lactating Holstein cows. J. Dairy Sc. (Suppl. 1):319 (Abstr.). Bedgar, S.E., J.W. Schroeder, M.L. Bauer, and W.L. Keller. 2005. Intake, duodenal flow, and ruminal biohydrogenation of fatty acids in Holstein steers fed canola supplemented dairy lactation diets. J. Dairy Sci.88(Suppl. 1):179. Bedgar, S.E., J.W. Schroeder, M.L. Bauer, and W.L. Keller. 2005. Fatty acid changes in the digestive tract of Holstein steers fed canola supplemented dairy lactation diets. J. Dairy Sci. 88:1923. Bedgar, S.E., J.W. Schroeder, M.W. Chichlowski, M.L. Bauer, and S.A. Soto-Navarro. 2004. Ruminal characteristics and rate, site, and extent of digestion of dairy diets supplemented with canola fed to Holstein steers. J. Dairy Sci. 87(Suppl. 1):215. Bequette, B.J., Owens, S.L., El-Kadi, S.W., Sunny, N.E., & Shamay, A. (2005) Use of 13C-mass isotope distribution analysis (MIDA) to define precursors for lactose and amino acid synthesis by bovine mammary explants. J. Dairy Sci. 88(Suppl. 1):289. Bobe, G., B.N. Ametaj, R.A. Nafikov, D.C. Beitz, and J.W. Young. 2004. Relationships between milk fatty liver and health and reproductive performance in Holstein Cows. Abstr. A-40, 12th Int. Conf. Prod. Dis. Farm Animals. p. 40. Braud, T. W., H. G. Bateman, II, C. C. Williams, C. C. Stanley, D. T. Gantt, C. F. Hutchison, J. D. Ward, P. G. Hoyt, and G. A. Sod. 2005. Effects of protein source on ruminal and total tract nutrient digestibility in non-lactating Holstein cows. J. Dairy Sc. (Suppl. 1):321 (Abstr.). Brown, N., V. Ishler, R. Chung, T. Cassidy, K. Hyler and G. A.Varga. 2005. Effect of forage processing and corn particle size on milk production and composition, and nutrient digestibility for high producing Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 99. Chung, Y.-H., T. W. Cassidy, I. D. Girard, P. Cavassini, and G. A. Varga. 2005. Effects of rumen protected choline and dry propylene glycol on feed intake and blood metabolites of Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 61 Chung, Y. H., T. W. Cassidy, I. D. Girard, P. Cavassini and G. A. Varga. 2005. Effects of rumen protected choline and dry propylene glycol on production responses of periparturient Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 61 Davis L, Weber Nielsen M, Keisler D, Chapin L, Liesman J, VandeHaar M 2005 Increasing time on a high energy diet increases expression of leptin in the mammary gland of prepubertal heifers.. J Animal Sci 83 (Suppl 1):79. Davis L, VandeHaar M, Liesman J, Chapin L, Weber Nielsen M 2005 Effects of an intensified compared to a moderate feeding program during the pre-weaning period on body growth and pubertal age in Holstein heifers.. J Animal Sci 83 (Suppl 1):386. DeFrain, J. M., Hippen, A. R., Kalscheur, K. F., Schingoethe, D. J. 2005. The impact of ruminal butyrate production and plasma betahydroxybutyrate on the glycemic status of transition cows. Journal of Dairy Science 88:1923 (abstr). DeFrain, J. M., Hippen, A. R., Kalscheur, K. F., Tricarico, J. M. 2005. Feeding an alpha-amylase enzyme preparation to improve the glycemic status and performance of transition dairy cows. Journal of Dairy Science 88:1923 (abstr). Dhiman, T. R., S. A. Hagos, J. L. Walters, and S. Tamminga. 2005. Conjugated linoleic acid (CLA) and omega fatty acids in milk from cows fed green chopped forage. J. Dairy Sci. 88 (Suppl. 1):276. Dhiman, T. R., A. L. Ure, and S. Nam. 2005. Conjugated linoleic acid (CLA) content of milk and meat products and its intake in humans. J. Dairy Sci. 88 (Suppl. 1):181. Donkin, S., J. Knapp, M. VandeHaar, and B. Bequette. 2005. Regulation of key metabolic processes in lactation. JDS 88(Suppl.1):124. El-Kadi, S., Baldwin, R., VI, Sunny, N., Owens, S.L., & Bequette, B.J.. (2005) Postruminal protein infusion increases leucine use by the gastrointestinal tract of sheep while glucose utilization remains unchanged. J. Anim. Sci. 83(Suppl. 1):128. Ellis, E. J. A., S. Solaiman, W.G. Bergen, and K. A. Cummins. 2005. Effect of dietary copper supplementation on fatty acid profile of muscle, mesenteric, and subcutaneous adipose tissue in goat kids. J. Dairy Sci. 88 (Suppl.1): 192 Firkins, J. L., A. N. Hristov, M. B. Hall, and G. A. Varga. 2005. Integration of ruminal metabolism in dairy cattle. J. Dairy Sci. 88 (Suppl 1): 124. Golombeski, G. L., Kalscheur, K. F., Hippen, A. R., Schingoethe, D. J. 2005. Highly fermentable sugars and slow-release urea in diets fed to lactating dairy cows. Journal of Dairy Science 88:1921 (abstr). Hall, M. B., and S. J. Rymph. 2005. Definitions of feed analysis methods as sources of error in nutritional models. Animal Science Modelers Meeting, Cinncinati, OH. July 23, 2005. Hall, M. B. 2005. Ruminal acidosis: beyond the rumen. J. Dairy Sci. 88 (Suppl. 1): 377. Hall, M. B. 2005. Starches and sugars: conceptual and analytical challenges. J. Dairy Sci. 88 (Suppl. 1): 347. Hanigan, M. D., H. G. Bateman, J. G. Fadel, and J. P. McNamara. 2005. Metabolic models of ruminant metabolism: Recent improvements and current status. J. Dairy Sc. (Suppl. 1):125 (Abstr.). Hippen, A. R. 2005. Dietary supplements for prevention of fatty liver and ketosis. Journal of Dairy Science 88:1921 (abstr). Jones, C., E. Pajor, S. Donkin, J. Marchant-Forde, and M.M. Schutz. 2005. Effect of recorded calf vocalizations on milk production with an automatic milking system. J. Dairy Sci. 88:1617. Karnati, S.K.R., J.T. Sylvester, Z. Yu, N.R. St-Pierre, and J.L. Firkins. 2005. Detecting changes in bacterial and protozoal populations in ruminal and omasal samples from cows fed supplemental methionine. Proc. Conf. Gastrointestinal Function, p. 13. Kleinschmit, D. H., Ladd, J. M., Schingoethe, D. J., Kalscheur, K. F., Hippen, A. R. 2005. Ruminal and intestinal digestibility of distillers grains with solubles varies by source. Journal of Dairy Science 88(Suppl 1):186 (abstr). Kleinschmit, D. H., Schingoethe, D. J., Kalscheur, K. F., Hippen, A. R. 2005. Evaluation of various sources of corn distillers dried grains plus solubles (DDGS) for lactating dairy cattle. Journal of Dairy Science 88:1922 (abstr). Lew BJ, Liesman JS, VanDorp TE, Oliveira MDS, Sipkovsky S, VandeHaar MJ 2005 Effects of diet and bST on gene expression profile in the liver of heifers. J Animal Sci 83 (Suppl 1):25. Lew BJ, Liesman JS, Oliveira MDS, VandeHaar MJ 2005 Effects of diet and bST on expression of leptin and leptin-receptor in mammary parenchyma of heifers. J Animal Sci 83 (Suppl 1):209. Mpapho, G. S., Hippen, A. R., Kalscheur, K. F., Schingoethe, D. J. 2005. Long term feeding of wet corn distillers grains and lactation performance of dairy cows. Journal of Dairy Science 88(Suppl 1):394 (abstr). Nafikov, R.A., B.N. Ametaj, G. Bobe, K.J. Koehler, J.W. Young, and D.C. Beitz. 2004. Prevention of fatty liver in transition dairy cows by subcutaneous glucagon injections. A-41, 12th Int. Conf. Prod. Farm Animals, p. 40. Reveneau, C., M.L. Eastridge, and J.L. Firkins. 2005. Source and amount of pelleted cottonseed influences fat digestibility and milk fat composition through ruminal metabolism of fatty acids in lactating cows. J. Anim. Sci. 83(Suppl. 1):372-373. Reynal, S.M., I.R. Ipharraguerre, M. Liñeiro, A.F. Brito, G.A. Broderick, and J.H. Clark. 2005. Ruminal Outflow of Soluble Amino Acid Fractions in Lactating Dairy Cows. J. Dairy Sci. 88(Suppl. 1):89. Reynolds, C., B. Bequette, and J. Knapp. 2005. Nutrient supply for milk production by splanchnic tissues in dairy cows. JDS 88(Suppl.1):124. Rodriguez, S.M., C.A. Bidwell, and S.S. Donkin. 2005. Translational efficiency of bovine pyruvate carboxylase 5 untranslated region mRNA variants. FASEB J. 19:A317. Sumner, J.S. and J. P. McNamara 2005. Effects of dietary chromium propionate and calcium propionate on adipose tissue metabolism and milk production of dairy cattle in the transition period. J. Dairy Sci 88(Suppl 1): 167. Tyrrell, H, and K.A. Cummins. Metabolic relationships in supply of nutrients in lactating cows. J. Dairy Sci. 88 (Suppl.1): 124. Tyler, P. J., K. A. Cummins, C. W. Wood, and B. Wood. 2005. Effect of season on ammonia volatilization from urine and beef and dairy feces. J. Dairy Sci. 88 (Suppl.1): 44. Ungerfeld, E., Bequette, B.J., Owens, S.L., & Kohn, R. (2005) Measurement of volatile fatty acid interconversion as a means to study the role of thermodynamics in the control of fermentation. J. Dairy Sci. (Suppl. 1) VandeHaar M 2005 The energy system of the 2001 Dairy NRC: Challenges for a ration formulation program. J Animal Sci 83 (Suppl 1):393. Van Saun, R. J., A. Todd, G.A. Varga. 2005. Serum Mineral Concentrations and Risk of Periparturient Disease. Amer. Assoc. Bov. Pract. Wang, L., B. Ametaj, J.A. Story, S.S. Donkin, and D.E. Bauman. 2005. Milkfat naturally enriched with conjugated linoleic acid alters expression of genes for lipid metabolism in the liver, but not in adipose tissue in growing female rats. FASEB J. 19:A1501. Williams, E.L., S. Rodriguez, D.C. Beitz, and S.S. Donkin. 2005. Effects of short-term glucagon administration on gluconeogenic enzymes in the liver of mid-lactation dairy cows. J. Dairy Sci. 88 (Suppl. 1)/J. Anim. Sci. 83 (Suppl. 1):79. Donkin, S.S., J.R. Knapp, M.J. VandeHaar and B.J. Bequette. 2005. Regulation of Key Metabolic Processes in Lactation. J. Dairy Sci. 88 (Suppl 1):124. Williams, E.L., S.M. Rodriguez, D.C. Beitz, and S.S. Donkin. 2005. Effects of short-term glucagon administration on gluconeogenic enzymes in the liver of mid-lactation dairy cows. J. Dairy Sci. 88 (Suppl 1):79 Theses and Dissertations Braud, T. W., 2005. Effects of Protein Sources with Differing Ruminal Degradation Characteristics on Nutrient Digestibilities and Flows through Various Segments of the Gastrointestinal Tract of Non-lactating Hostein Cows. M. S. Thesis, Louisiana State University and A&M College, Baton Rouge. Bedgar, S. E. December 2004. Metabolism of Fatty Acids from Canola Supplemented Dairy Lactation Diets. M.S. Thesis, Golombeski, G. L. 2005. Slow-release urea and highly fermentable sugars in diets fed to lactating dairy cows. M.S. Thesis, South Dakota State University, 71 pp. Linke, P. L., Hippen, A. R. 2005. Ruminal and plasma responses in dairy cows to drenching or feeding glycerol. South Dakota State University Journal of Undergraduate Research 3:49-60.

Impact Statements

Interactions among endocrines responding to energy signals were elicited which will help improve the industrys ability to manage growth rates in developing heifers to minimize costs while maintaining future production potential.
Precursor:product relationships for conjugated linoleic acid formation in milk were extended adding to the current knowledge base. This effort helps establish the potential for CLA enhancement and the economics of such enhancement.
Greater quantities of grass hay may be included in lactating cow diets without compromising milk volume or components and enhancing DM efficiency provided that ruminal fermentability of carbohydrates are matched to the forage utilized.
The environmental stability of nitrogen in manure can be improved by increasing hindgut fermentation.
As much as 2 kg/d of glycerol from soy biodiesel production may be fed to lactating dairy cows with no significant impact on production.
Wet distillers grains with solubles (DGS) may be fed at a rate up to 15% of diet DM with no significant impact on health, production, or composition of milk. Wet DGS had less RUP than dried DGS, but among the dried DGS, RUP varied considerably. Processing differences between ethanol plants may significantly affect DGS quality.
The dose response effects of rumen protected choline were established.
Both omasal sampling and a modified continuous culture systems show promise for evaluation of protozoal ecology and quantifying generation time as compared to current methods.
Supplemental methionine or methionine analog was found to affect ruminal bacterial but not protozoal ecology indicating that some consideration of ruminal effects is required when conducting economic evaluations of these additives.
Blood glucose concentrations were found to be increased when diets were supplemented with chromium or glycerol or cows were injected with glucagon. Elevated glucose concentrations were associated with reductions in blood non-esterified fatty acids which should have positive impacts on the incidence of ketosis.
Understanding the control of the pyruvate carboxylase and phosphor-enol-pyruvate carboxy kinase genes will be used to devise management strategies to enhance productivity, cow health and well being.
Research in modelling energy balance provides a foundation for changing future metabolic models to better account for energy expenditures in the animal and more accurate predictions of energy balance in the cow.
A meta-analysis of literature data provided parameter estimates for the value of various protein sources in lactating diets.
Demonstration of the accuracy of predictions of N partitioning to milk and urine establishes a foundation for improving predictions of NH3 emissions from manure.
Progress was made in developing tools to quantitatively integrate genomic and metabonomic information.
Sensitivity of the NRC and Molly models was conducted providing an assessement of the importance of accurate input measurements.

Date of Annual Report: 12/15/2006

Report Information

Annual Meeting Dates: 10/30/2006 - 10/31/2006
Period the Report Covers: 10/01/2005 - 09/01/2006

Participants

Benfield, David (benfield.2@osu.edu) - Administrative Advisor; McNamara, John (mcnamara@wsu.edu) - Washington State University; Johnson, Heidi (HAJohnson5@netscape.net) - University of California-Davis; Armentano, Louis (learment@wisc.edu) - University of Wisconsin; Hannigan, Mark (mhanigan@vt.edu) - Virginia Polytechnic Institute and State University; Donkin, Shawn (sdonkin@purdue.edu) - Purdue; Schwab, Charles (charles.schwab@unh.edu) - University of New Hampshire; Beitz, Donald (dcbeitz@iastate.edu) - Iowa State University; Bequette, Brian (bbequett@umd.edu) - University of Maryland; Erdman, Richard (rerdman@umd.edu) - University of Maryland; Schroeder, J. W. (JW.Schroeder@ndsu.edu) - North Dakota State University; Firkins, Jeffrey (firkins.1@osu.edu) Ohio State University; VandeHaar, Micheal (mikevh@msu.edu) - Michigan State University; Hippen, Arnold (arnold.hippen@sdstate.edu) - South Dakota State University; Bradford, Barry (bbradford@ksu.edu) - Kansas State University; Knapp, Joanne (JKnapp@heiskell.com) - JD Heiskell

Brief Summary of Minutes

October 30

Meeting convened at 8:00 AM. Following confirmation of the agenda we proceeded to remarks from the Administrative Adviser. Remarks concerned the timetable and the process to get a new project to replace the current NC-1009 approved. Written guidelines for computer submission of needed documentation were provided. As no CSREES representative was present at the meeting Dr. Benfield reminded us that we had previously received four electronic files with information from CSREES on NRI, budget themes, FY07 budget (president, house and senate versions pending finalization), and NRI personnel. Dr. Benfield also fielded questions from the committee on both topics specific to the project submission and more general questions on funding direction. The committee appreciates Dr. Benfield's commitment to the project.

Dr. Chuck Schwab discussed the current state of the Feed Analysis Consortium, inc. (FeedAC, www.feedac.org; formerly the Ruminant Feed Analysis Consortium).

For the remainder of the morning discussion was led by Dr. J. McNamara. The discussion during this time considered how the objectives of the new project would relate to each other and to objectives of the current project. Consensus was reached that the past strength of the committee was the breadth of committee members to understand how variations in feed composition interact with the dynamic metabolic processes inherent in the luminal microbial population and animal tissues and that continued interaction and integration was essential to meet the ultimate goal. It was also reaffirmed that improved understanding of these processes was continuous and incremental. Further, there is a commitment to incremental incorporation of knowledge into applied computer models and other quantitative criteria that can be used in the actual practice of feeding cows to optimize economic, food quality and environmental concerns. There was discussion of how qualitative, and semi-quantitative, and quantitative data obtained at microbial or tissue level feeds into ultimate practice. This process will require experimentation at all levels and will also involve additional computer modeling at an intermediate level to aide in integration and sensitivity analysis. This process is by nature iterative and is dependent on interaction among participants working on different aspects with a common goal.

After breaking for lunch, the committee reconvened as a whole and then shortly broke up into Objective 1 (feed and microbial oriented) and Objective 2 (tissue metabolism oriented) subgroups with Objective 3 (modeling oriented) participants distributed into these groups. Planned work and opportunities for collaboration were discussed.

October 31:

Convened at 8:00 AM. Plans of work under objectives 1,2, and 3 were discussed further to explore more potential areas for collaboration.

Officers for next year were elected. Armentano (Nov 05-Oct 06 Secretary) was promoted to Chair as per committee tradition. Bequette was elected as secretary (Nov 06- Oct 07) and chair (Nov 07- Oct 08) elect. Meeting for October 2007 (assuming success of the new project proposal) was set for Monday October 22 through noon October 23 in Indianapolis. Donkin offered to aid Armentano with meeting arrangements.

McNamara will provide a draft of the project proposal electronically in the week following this meeting. Members were reminded to provide feedback to John McNamara on the proposal in time for a December 1 submission. Chair Hippen is responsible for the annual report and Secretary Armentano is responsible for the minutes (due December 15 in NIMSS).
Group adjourned at about 11:00 am.

Minutes Attachment:

Attachment

Accomplishments

Objective 1 To quantify properties of feeds that determine the availability of nutrients critical to milk production. Research at PA demonstrated that ruminally protected choline (RPC) and dry propylene glycol (PG) fed to periparturient dairy cows had influences on blood metabolites via different mechanisms and through interactions with each other. Individual or additive effects of RPC or dry PG, however, did not elicit production responses likely due to a relatively positive energy balance based on pre and postpartum BHBA and NEFA values. Further research indicated that, while supplementing RPC, adding PG to the diet increased the demand of B12 for propionate metabolism and therefore, plasma B12 decreased. Without RPC, adding PG had no effect on B12. The absence of response to PG in cows fed no RPC, which also had lower plasma folates, possibly indicate that B12 is not fully available for methylmalonylCoA mutase when the efficiency of methionine synthase is limited by a lack of folates. The effects of monensin (M) on ruminal VFA and plasma glucose (Glu) metabolism was modeled at PA using transition dairy cows and isotopic tracers. WinSAAM, the Windows version of ConSAAM, adequately described and integrated ruminal VFA and blood glucose kinetics, resulting in accurate quantification of VFA and glucose metabolism. Monensin affects interconversions of ruminal VFA, increases propionate originated gluconeogenesis, and reduces glucose disposal rate in transition cows. Effects of concentration and duration of M on milk production efficiency was evaluated in multiparous Holstein cows. Results indicate that, in cows at peak lactation, M effects on ruminal fermentation may be achieved as soon as 10 d of application and short term application of 600 mg/g Rumensin dose may support milk production with a concomitant reduction in intake and no apparent utilization of body energy stores. The correlation (r = -0.66, P= 0.0002) between milk production efficiency and acetate to propionate ratio indicate an involvement of ruminal fermentation in improved feed utilization. Madin-Darby Bovine Kidney cell lines were characterized for use as an in vitro bovine model for peroxisome proliferator-activated receptors (PPARs). The CPT-1 (Carnitine Palmitoyl Transferase-1), ACOX (Acyl CoA Oxidase), LPL (Lipoprotein Lipase) and GAPDH (Glyceraldehyde Phosphate Dehydrogenase) were analyzed using semiquantitative and real time PCR. The results suggest that the MDBK cell line is a promising model to evaluate the role of PPARs for the bovine. (PA). Following research involved treatment of Madin-Darby Bovine Kidney cells with fatty acid PPAR agonists. Of tested fatty acids, palmitate was the most effective at affecting PPAR responsive genes in MDBK cells, followed by linolenic and linoleic while oleic and CLA fatty acids were ineffective. Samples of wet distillers grains from 3 plants were analyzed for fat content by acid hydrolysis/petroleum ether, di-ethyl ether, and fatty acid determination by GLC. (WI) GLC analysis shows significant variation in oil content of these samples. Acid hydrolysis ether extract underestimated fatty acid content and did not correlate well with variation in fatty acid content. Di-ethyl ether also did not correlate much better with fatty acid content. Fatty acid quantification is recommended for determination of fat content in wet distillers grains. In an experiment designed to test the effect of inclusion of protected amino acids, blood meal, or fish meal as high biological value proteins to distillers grains-based diets, milk protein content was improved somewhat by the addition of protected amino acids and blood meal. Diets were not improved by protein supplements designed to improve the lysine delivery of the basal diet, though cows were responsive to an overall improvement in protein amount. (WI) Holstein bull calves were fed starter feeds containing 0, 28, or 56% DDG. (SD) Inclusion of DDG in calf starters increased the number of papillae in rumens per unit area; however the positive influence of this was diminished by decreased size and surface area of individual papillae. Growth of calves were not affected by addition of distillers grains into diets. To determine the effects of feeding corn germ on dairy cow performance, diets for lactating cows were formulated with increasing concentrations of corn germ at 0, 7, 14, and 21% of the diet DM. Inclusion of corn germ at 7% and 14% of dietary dry matter resulted in increased milk and fat yields, however, inclusion of corn germ at 21% of diet DM decreased concentration and yield of milk fat. (SD) To measure the effects of feeding ground flaxseed on BW, BCS, milk yield, milk composition and milk fatty acid profile, 24 Holstein cows fed diets containing whole sunflower seed, ground flax seed, or linseed oil from 7 to 105 DIM. (ND) Cows fed ground flaxseed increased milk fat concentration and yields of FCM and SCM when compared with diets containing linseed oil or whole sunflower seed. To assess the role of protozoa in biohydrogenation (BH) of dietary unsaturated FA, and to determine if inhibition of methanogenesis increased BH, dual-flow continuous culture vessels were modified to retain protozoa. (OH) Experimental treatments were 10-d faunated or defaunated (DEF) sub-periods. Once daily, the fermenters were fed 40 g of a 30:70 concentrate:forage diet containing either no additive, 4% animal-vegetable fat, bromoethanesulfonate (BES 250 µM, methane inhibitor), or monensin ( MON 2.5 µM). Digestibilities of OM and NDF were increased, whereas total VFA concentration decreased by DEF. Methanogenesis was unaffected by defaunation but tended to be decreased by MON. The acetate:propionate ratio decreased and molar proportions of butyrate, isobutyrate, and isovalerate increased by DEF. Isovalerate was increased by MON. Dietary fat increased the flow (mg/day) of the trans (t) BH intermediates t10 and t11, and the effect was more pronounced by DEF. There was no interaction for total t18:1/total unsaturated FA. The flow of CLA was unaffected by DEF or by treatments other than added fat. MON did not affect flows of t10, t11, or total t18:1 FA. Protozoal counts were not different between dietary treatments, but BES increased the generation time from 43.2 to 55.6 h. Subsequent cluster analysis of denaturing gradient gel electrophoresis confirmed a loss of a group of protozoa-associated methanogens (identified by sequence analysis of excised bands). Ruminal, post-ruminal and total tract crude protein (CP) digestion of two low-quality forages originating from central Iranian deserts (Kochia scoparia, Atriplex domorphostegia) were evaluated using in situ, three-step, and DaisyII incubator procedures. (MN) Ruminal CP disappearance of Kochia was lower than Atriplex after 12 h incubation in the rumen, but there was no difference (P > 0.05) between forages after 16 h incubation. Likewise, total tract CP digestion of Kochia (86.6 %) tended to be lower than Atriplex (88.6 %) when using the three-step procedure, while total tract CP digestion of Kochia (88.4%) was significantly less than for Atriplex (91.3%) when using the DaisyII procedure. There was a good relationship between the procedures for evaluating CP digestion of halophyte forages. A combination of in-situ and in vitro evaluations of mechanical-extracted soybean meal with fresh soy gums indicate that application of fresh soy gums onto mechanically extracted soybean meal can increase RUP but that processing can overprotect protein from digestion in the intestine. (MN) Using a three-step procedure to evaluate consistency in processing procedures, intestinal protein digestion of four ruminal protected soybean products and three sources of distillers dried grains with solubles were evaluated. (MN) Variation in processing of each protected soybean product was not great; however mean intestinal protein digestion varied greatly, ranging from 68.2 to 83.0% among the four soybean products. For distillers grains there was a fairly large variation in processing of DDG-A (range of 69.6 to 75.5%), and DDG-C (range of 77.2 to 85.3%). From these types of observations, it appears that the three-step procedure can be a useful method for evaluating quality control of protein within and among processing procedures. (OH) Historically, research evaluating ruminal nitrogen transactions has primarily focused on aspects concerning the degradative, assimilatory and metabolic fates of nitrogenous compounds. The microbiological aspects of these processes have been integrated into nutritional goals of improving the efficiency of microbial protein synthesis, maximizing amino acid supply to the host animal, and (or) minimizing the loss of nitrogenous compounds in animal waste. As described in the paper by Morrison and Yu, microbiological techniques have advanced from phenotypic descriptions of pure and mixed cultures to metagenomic comparisons of population structure in vivo. Correspondingly, although major shifts in microbial populations have been associated with large in vivo treatment differences, more narrow treatment differences have demonstrated shifts in microbial populations that are only relatively comparable to differences among animals fed the same diets, indicating considerable variability in microbial populations occupying similar niches. As nutritionists move toward more sophisticated dietary modeling approaches based on some overall average animal response, we must better account for the variability in model predictions for feeding groups of animals to decrease current reliance on dietary safety factors and anecdotal animal assessment strategies to prevent ruminal acidosis or shortages of rumen degraded protein. Dietary factors influencing ruminal degradative capacity and outflow of microbial protein include the types and numbers of protozoa, the availability of specific nitrogenous and carbohydrate fractions, rumination activity, stratification and location in the rumen, and time after feeding. Diet, fecal, urine, and manure samples were collected from dairies in the Pacific Northwest and analyzed for chemical and isotopic composition and for ammonia volatilization rates in vitro (ID). Cumulative ammonia loss was estimated based on daily emissions and daily manure and ammonia samples were analyzed for 15N abundance. Correlations between cumulative ammonia losses and 15N abundance of manure N ranged from r = 0.70 to r = 0.92 and the relationship was linear. This study demonstrated that ammonia emitted from cattle manure during storage is highly depleted in 15N and changes in 15N of aged manure could potentially be used to predict ammonia emissions from cattle manure. Sugar supplementation can stimulate rumen microbial growth and possibly fiber digestibility; however, increasing ruminal carbohydrate availability relative to RDP can promote energy spilling by microbes or decrease rumen pH. Therefore, an experiment was conducted with lactating cows to determine the effects of matching molasses supplementation with urea and monensin supplementation on corn silage (CS) or alfalfa hay (AH)-based diets. (OH) All diets were balanced to have 16.2% CP, 18.0% forage NDF and 41.0% NFC. Treatments had no effect on milk or protein yield, but monensin decreased milk fat from 3.25 to 2.72 % in CS diets but not in AH diets. Rumen ammonia concentration decreased with the addition of molasses but increased with molasses + urea in the CS diets. Ammonia and MUN remained unchanged in the AH diets. Diets did not affect (P>0.21) ruminal pH or DMI. Sugar supplementation might require urea to support microbial protein synthesis in corn silage diets balanced for moderate CP and perhaps especially if monensin is fed. To compare the effects of whole plant silage and grain produced from NutriDense® (ND), leafy NutriDense® (LND), or a conventional yellow dent (YD) hybrid on rumen fermentation, total tract nutrient digestibility, and performance 20 multiparous Holstein cows, four of them surgically fitted with ruminal cannulas, were fed diets containing 30.6% corn silage and 27.7% corn grain provided from the three hybrids. (IL) Feeding ND grain and (or) LND silage reduced the intakes of nonfibrous carbohydrates and starch but increased the intake of ether extract. Apparent digestibility of starch in the total tract was highest for the diet that contained LND silage and YD grain, whereas the amount and percentage of ether extract that was apparently digested in the total tract was increased and tended to be increased, respectively, by the addition of ND grain and (or) LND silage to the diets. Ammonia nitrogen in the ruminal fluid tended to be increased by feeding ND grain and (or) LND silage as did concentration of milk urea nitrogen. The ND grain and LND silage were similar to the conventional grain and silage for the feeding of lactating dairy cows. Objective 2 To quantify metabolic interactions among nutrients that alter synthesis of milk. The mRNA levels of NADP+-dependent isocitrate dehydrogenase (IDH1) have been observed to increase by 2.3-fold after parturition compared to late pregnancy and remained elevated thereafter. (AZ) Quantification in changes of IDH1 expression showed that IDH1 mRNA increased in parallel with ²-casein expression induced by extracellular matrix. Fetal calf serum and insulin repressed, whereas prolactin stimulated the expression of IDH1 mRNA in a dose-dependent fashion. Inhibitory effects of insulin on IDH1 mRNA levels were antagonized by cotreatment with prolactin. In contrast, treatment with prolactin in the presence of extracellular matrix further increased IDH1 mRNA and protein accumulation. Prolactin-induced IDH1 expression was inhibited by the mitogen-activated protein kinase (MAPK) inhibitors PD98059 and U0126, and Janus tyrosine kinase 2 (Jak2) inhibitor AG490, suggesting that both MAPK and Jak2 contribute to regulation of IDH1 expression by prolactin. Finally, treatment of BME-UV cells with ±-ketoglutarate and palmitic acid reduced IDH1 transcript levels. Expression of IDH1 in bovine mammary epithelium is modulated by regulators of differentiation including extracellular matrix and lactogenic hormones as well as metabolic effectors. Pilot tracer and gene expression were studied in lactating mice (days 11-13). (MD) Initial findings confirm those observed with bovine mammary explants in that plasma glucose is not the sole nor main source of carbon skeletons for mammary lactose (glucose and galactose) synthesis. In fact, over 50% of lactose is synthesized de novo within the mammary gland of the mouse with nearly equal contributions from the Krebs cycle (via PEPCK-c) and from plasma glycerol. Gene expression of PEPCK isoforms in the liver and in the mammary glands were similar to those previously observed in the bovine mammary gland. Flux and contributions to overall Krebs cycle metabolism of primary substrates available to the rumen and small intestinal tissues were determined by using rumen epithelial (REC) and duodenal mucosal cells (DMC) isolated from Angus bulls. Data suggest that the partial catabolism of glucose to lactate and possibly alanine may play a role in conserving glucose 3-carbon units for hepatic gluconeogenesis. Furthermore, increasing the supply of glutamate to REC and DMC increased the flux of Krebs cycle intermediates from glutamate, thereby reducing the entry of other substrates entering at or beyond ±-ketoglutarate.(MD) In order to better understand transcriptional regulation of phosphoenolpyruvate carboxykinase (PEPCK), a rate-limiting enzyme for gluconeogenesis, an experiment was conducted to clone and sequence the bovine PEPCK gene and to identify promoter elements. (IN) Bovine genomic sequence information, available through the National Center for Biotechnology Information (NCBI) and BLAST searched for matches to the 5 end of PEPCK-C based on sequence data previously generated in our laboratory by cDNA cloning (Genbank accession: NM_174737) allowed cloning of a 1000 bp sequence that included the first few bases of the coding region and ligated the sequence to a luciferase reporter gene. Promoter truncations have been generated. In efforts to characterize the effect of dexamethasone treatment on induction of gluconeogenesis in cattle through pyruvate carboxylase (PC), putative glucocorticoid response elements in the second and third promoter region of bovine PC have been identified. (IN) Approximately 1200 bp upstream of the first exon that is associated with each of the three promoters of bovine PC was amplified from bovine genomic DNA. Promoter/reporter constructs were generated for each promoter region. Promoters were truncated from the 5 end to generate a series of constructs for each of the three promoters which have been transfected separately into rat hepatoma H4IIE cells. Stable cell lines containing the promoter constructs have been selected and amplified. Experiments are ongoing to determine the minimal promoter elements necessary for activity of each promoter and responsiveness to glucocorticoids. Injection of cows with 5mg/d of glucagon and glucagon plus 500 ml/d of glycerol drench for 14 d after calving increase plasma glucose and insulin and decrease NEFA concentration on a short-term basis. (IA) Glucagon plus glycerol decreased total liver lipids and increase liver glycogen content. Furthermore, glycerol decreased plasma NEFA concentration and accelerated hepatic TAG removal. These responses suggest that glucagon, glycerol, and glucagon plus glycerol have the potential to treat fatty liver disease in dairy cows. Poor biological efficiency of nitrogen (N) use decreases farm profitability and results in substantial N waste. If we could find ways to produce high quantities of milk per cow with only 15% CP diets, we could decrease urinary N excretion by ~40%. To identify genes associated with metabolism that are key regulatory points and are up- or down-regulated by protein-deficient diets, 12 lactating cows were fed either a standard diet fed to high-producing lactating cows with ~19% protein or diets containing 11 or 15% CP. (MI). Feeding 11% CP for 10 d reduced milk yield 16%, increased the conversion of feed N to milk N by 47%, and decreased milk urea nitrogen (MUN) 66%. Feeding 11% CP for 3 d increased the efficiency of N use 54% and dramatically decreased urinary N excretion 67%. With increased dietary protein, we observed a linear increase in BUN and MUN and a linear decrease in creatinine. As the calculated body protein balance indicates, this was not a sustainable metabolic adaptation. Gene expression in tissues using our BMET microarray is an ongoing evaluation. A study on dietary protein requirements evaluated the effects of phase feeding on lactation performance. (AL) Cows in 4 pens, two pens per treatment were fed either a standard 17% or a 13 and a 17% CP diet on a three day cycle for 24 d periods in a double switchback design. Diet had no effect on milk production, but milk protein content for the 17% CP diet was 3.34% compared with 3.21% for the phase-feeding treatment. To: 1) establish the relationship between transfer of blood urea-N to and utilization of recycled urea-N within the digestive tract (GIT) and 2) establish the relationship between plasma urea concentration and urea-N recycled to the GIT, independent of diet induced events occurring within the GIT, 4 sheep (28.1 ± 0.6 kg) were fed a low protein (6.8% CP, DM basis) diet and assigned to four rates of i.v. urea infusion (0, 3.8, 7.5, 11.3 g urea-N/d; 10-d periods) according to a balanced 4 X 4 Latin square design. Results suggests that transfer of blood urea to the GIT is highly dependent upon blood urea concentration and it is less limiting for nitrogen retention than is the efficiency of capture of recycled urea-N by microbes in the GIT. (MD) To determine the effect of reducing ruminally degradable protein (RDP) with constant ruminally undegradable protein in mid-lactation dairy cow diets 40 mid-lactation Holstein and Jersey by Holstein cross-bred cows were fed diets with CP contents of 18, 16.8, 15.7, or 14.5% and formulated RDP contents of 11.3, 10.4, 8.5 and 7.6% of dry matter, respectively. (VA) Milk urea nitrogen decreased linearly as the CP content of the diets declined. Results suggest that mid-lactation dairy cows can be fed diets with RDP contents as low as 8.5% of dry matter, which is less than that recommended by NRC (2001). The use of principal component analysis (PCA) and multivariate analysis (MA) to assess the relationship between milk fatty acid (FA) concentration (%) of total FA methyl esters) and diet induced milk fat depression (MFD) was examined. (MD) The PCA and MA analysis in the present study, confirms previous reports that t10-18:1 may be involved in MFD and suggest that t6,7,8-18;1 could also be important in MFD. Among the CLA isomers, the t10c12 CLA and t7c9 CLA isomer were consistently negatively correlated to milk fat percentage. Following PCA, a lactating mouse model was used to re-examine isomeric effects on fat depression. The study treatments were: 1) c18: 1- c9 (oleic acid)-Control; 2) Partially hydrogenated vegetable fat (negative control), 3) t7-18:1; 4) t9-18:1; 5) t11-18:1; and 67) t10c12-18:1 at 5% of total calories. A preliminary report showed that t10c12-18:1 and t7-18:1 depressed milk fat, confirming our principal components analysis. The relationships between mammary gene expression patterns were examined along with effects of a milk fat-depressing diet (MFD) on mammary gene expression patterns using microarray technology. (MD). Differentially expressed genes included 21 associated with insulin action, 24 with glucose metabolism, and 27 with cytokine action. Mammary from MFD had >3-fold down regulation for a gene encoding a novel nuclear protein responsible for normal triglyceride synthesis and induction of key lipogenic genes (e.g.PPARs, CEBPs) in mice. These data showed that milk fat depression is associated with complex changes in mammary transcript expression patterns. The lactation performance of dairy cows fed wet distillers grains (WDG) for a complete lactation was evaluated. (SD) Relative to a control diet not containing distillers grains, feeding of WDG at 15% of diet DM for the entire lactation increased milk component percentage and yields, feed efficiency, body condition and body weight gain while maintaining milk yield and feed intake. Feeding 15% of diet as WDG during the dry period through early lactation (-60 to 70 DIM) did not effect production of milk but increased milk protein content, BW, and BCS. Objective 3 To use these quantitative relationships to challenge and refine computer-based nutrition systems for dairy cattle. Recent model evaluations have looked at the sensitivity of model predictions to changes in nutrient content based on the underlying belief that knowing the impact of these pertubations on model predictions would allow for better allocation of resources when choosing nutrient analysis. In attempts to define the level of precision reasonably achievable by models, a dataset is being constructed from recently (past 3 to 5 years) published literature. The data set will be used to define the precision with which measures of economic importance related to milk production for dairy farms can be measured. (Akey) Because reports indicate that the 2001 NRC young calf sub-model tends to under-predict growth of calves and there is a known relationship between growth rate of replacement heifers and lactation performance, attempts to determine if there is a systemic bias to the sub-model are being made. Current efforts are to program the young calf sub-model into a spreadsheet format so that individual equations can be explored. It has been observed previously that the digestion and metabolism model known as Molly underpredicts milk component yield responses to nutrition and consequently overpredicts body energy store responses. (VA) To further account for this, cows were fed 0, 3, or 6 kg of concentrate daily throughout 670 d of lactation. Milk synthesis parameters for Molly and a more simple lactation model were fitted to the data to allow comparisons of model structure. The original model predicted lactose, protein, and fat yields with root mean square prediction errors (RMSPE) of 17.8%, 22.4%, and 20.1%, respectively. The RMSPE for predictions of lactose, protein, and fat yields by the revised model were 8.7%, 10.2%, and 11.8%, respectively with slope bias of 6.8, 2.8, and 2.8% of the MSPE, respectively. The RMSPE for predictions of body weight by Molly95 was 19.3% with mean and slope bias of 62.1 and 20.7%, respectively as compared to a RMSPE of 7.3% for the revised model with mean and slope bias of 9.7 and 2.9%, respectively. It was concluded that representing mammary synthetic capacity as a function of active cell numbers had merit relative to the original representation of mammary synthetic capacity in Molly. Using models, Molly and CPM Dairy, nutrient inputs were varied to assess their importance in animal outputs using typical CA dairy rations. (CA) The nutrient levels that varied were soluble carbohydrate (SC), starch, crude protein (CP), soluble CP (PS), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (LG), ether extract (EE), lysine and methionine and nutrients were varied individually, +/- 20% from base values. Animal outputs used to assess impacts of changes in ration nutrient inputs on model predictions were fecal nitrogen (N), urinary N, milk N (Molly only), microbial dry matter, milk (ME, MP and AA allowable milk in CPM Dairy), milk fat (Molly only) and milk protein (MP allowable milk protein in CPM Dairy). Both models had similar sensitivities to ration nutrient changes, and there was very little difference in model responses among rations. For both models, predicted animal outputs were most sensitive to changes in CP, NDF and PS (LG in CPM only; EE in Molly only) supporting the need for chemical analysis of these nutrients. Molly was sensitive to an amino acid (AA), even if it was not limiting animal production, due to N excretion in milk and urine. Estimated AA allowable milk in CPM was the only output that was sensitive to a limiting AA. Both models were insensitive to changes in SC, and ADF, indicating that model libraries for these values are adequate for ration formulation and/or evaluation.

Publications

Refereed publications of NC-1009 Committee members during 2006 Ametaj, B.N., B.J. Bradford, G. Bobe, R.A. Nafikov, Y. Lu, J.W. Young, and D.C. Beitz. 2005. Strong relationships between mediators of the acute phase response and fatty liver in dairy cows. Can. J. An. Sci. 85:165-175. Bateman, H. G., II, A. E. Beem, C. C. Stanley, C. C. Williams, and C. F. Hutchison. 2005. Case study: Using urine pH as a predictor for ketosis in transition dairy cows. Prof. Anim. Sci. 21:515-520. Benefield, B.C., M. Liñeiro, I.R. Ipharraguerre, and J.H. Clark. 2006. NutriDense Corn Grain and Corn Silage for Dairy Cows. J. Dairy Sci. 89:1571-1579. Chung, Y. H., H. G. Bateman, II, C. C. Williams, C. C. Stanley, D. T. Gantt, T. W. Braud, L. L. Southern, J. D. Ward, P. G. Hoyt, and G. A. Sod. 2006. Effects of methionine and lysine on fermentation in vitro and in vivo, nutrient flow to the intestine, and milk production. J. Dairy Sci. 89:1613-1620. DeFrain, J. M., A. R. Hippen, K. F. Kalscheur 2006. Feeding lactose to increase ruminal butyrate and the metabolic status of transition dairy cows. J. Dairy Sci. 89:267-276. DeFrain, J. M., Hippen, A. R., Kalscheur, K. F., J. M. Tricarico. 2005. Effects of dietary alpha-amylase on metabolism and performance of transition dairy cows. J. Dairy Sci. 88 (12):4405-4413. Douglas, G. N., T. R. Overton, H. G. Bateman, II, H. M. Dann, and J. K. Drackley, 2006. Prepartal plane of nutrition, regardless of dietary energy source, affects periparturient metabolism and dry matter intake in Holstein cows. J. Dairy Sci. 89: 2141-2157. Drackley, J.K., S.S. Donkin, and C.K. Reynolds. 2006. Invited Review. Major Advances in Fundamental Dairy Cattle Nutrition. J. Dairy Sci. 89 1324-1336. Edwards, J.E., Bequette, B.J., McKain, N., McEwan, N.R., & Wallace, R.J. (2005) Influence of flavomycin on microbial numbers, microbial metabolism and gut tissue protein turnover in the digestive tract of sheep. Br. J. Nutr. 94: 6470. El-Kadi, S.W., Baldwin, R.L.VI., Sunny, N.E., Owens, S.L., Bequette, B.J. (2006) Intestinal protein supply alters amino acid, but not glucose, metabolism by the sheep gastrointestinal tract. J. Nutr. 136: 12611269. Fadel, J. G. 2004. Estimating parameters of non-linear segmented models. Journal of Dairy Science. 87:169173. Firkins, J. L., A. N. Hristov, M. B. Hall, and G. A. Varga. 2006. Integration of ruminal metabolism in dairy cattle. J. Dairy Sci. 89:5561-5586. Golombeski, G. L, K. F. Kalscheur, A. R. Hippen, D. J. Schingoethe. 2006. Slow-release urea and highly fermentable sugars in diets fed to lactating dairy cows J. Dairy Sci. 89: 4395-4403. Gressley, T. F., S.M. Reynal, J.J. Olmos Colmenero, G.A. Broderick and L.E. Armentano. 2006. Development of a tool to insert abomasal infusion lines into dairy cows. J. Dairy Sci. 89: 3965-3967. Hammon, H. M., C. Philipona, Y. Zbinden, J.W. Blum, and S.S. Donkin. 2005. Effects of Dexamethasone and Growth Hormone Treatment on Hepatic Gluconeogenic Enzymes in Calves. J. Dairy Sci. 88:2107-2116. Hanigan, M.D., France, J., Mabjeesh, S.J., McNabb, W.C., MacRae, J.C., and Bequette, B.J. (2005). Mammary protein turnover estimated from phenylalanine kinetics in the lactating dairy goat. Can. J. Anim. Sci. 85: p. 548. Hill, T. M., J. M. Aldrich, R. L. Schlotterbeck, and H. G. Bateman, II. 2006. Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period. Prof. Anim. Sci. 22:252-260. Hill, T. M., J. M. Aldrich, R. L. Schlotterbeck, and H. G. Bateman, II. 2006. Effects of feeding rate and concentrations or protein and fat of milk replacers fed to neonatal calves. Prof. Anim. Sci. 22:374-381. Jacobs, J. L., F, Diez-Gonzalez, R. L. Phillips and M. D. Stern. 2005. Detection of transgenic maize Cry1Ab protein subjected to ruminal digestion. J. Anim. Feed Sci. 14(4):655-664. Liu W, Degner SC, Romagnolo DF. 2006. Trans-10, Cis-12 Conjugated Linoleic Acid Inhibits Prolactin-Induced Cytosolic NADP+-Dependent Isocitrate Dehydrogenase Expression In Bovine Mammary Epithelial Cells. J. Nutr. 136:2743-2747. Mesgaran, M. D. and M. D. Stern. 2005. Ruminal and post-ruminal protein disappearance of various tropical feeds determined by the mobile nylon bag, in vitro and three-step procedures. Anim. Feed Sci. Technol. Vol 118/1-2:31-46. Nafikov, R.A., B.N. Ametaj, G. Bobe, K.J. Koehler, J.W. Young, and D.C. Beitz. 2006. Prevention of fatty liver in transition dairy cows of subcutaneous injections of glucagon. J. Dairy Sci. 89:1533-1545. Oba, M., Baldwin, R.L., IV, Owens, S.L, & Bequette, B.J. (2005) Metabolic fates of ammonia nitrogen in ruminal epithelial and dudoenal mucosal cells isolated from growing sheep. J.Dairy Sci. 88: 3963-3970. Reveneau, C., C.V.D.M. Ribeiro, M.L. Eastridge, N.R. St-Pierre, and J.L. Firkins. 2005. Processing whole cottonseed moderates fatty acid metabolism and improves performance by dairy cows. J. Dairy Sci. 88:4432-4355. Tapia, M. O., M. D. Stern, A. L. Soraci, R. Meonuck, W. Olson, S. Gold, R. L. Koski-Hulbert, and M. J. Murphy. 2005. Patulin-producing molds in fermented feeds and effects of patulin on fermentation by ruminal microbes in continuous culture. Anim. Feed Sci. Technol. 119:247-258. Ure, A.L., T.R. Dhiman, M.D. Stern and K.C. Olson. 2005. Treated extruded soybean meal as a source of fat and protein for dairy cows. Asian-Aust. J. Anim. Sci. 18(7):980-989. Velez, J.C. and S.S. Donkin. 2005. Feed Restriction Induces Pyruvate Carboxylase but not Phosphoenolpyruvate Carboxykinase in Dairy Cows. J. Dairy Sci. 88: 2938-2948. Wheeler, E. F., P.A. Topper, Y. G.A. Varga, N. Brown, R.E Graves. V. Ishler, A.J. Heinrichs. V Blanes Vidal. 2006. Ammonia emission monitoring using flux chamber methods. In Proceedings AgEng 2006, World Congress. Bonn, Germany. 8 pp on CD. Wheeler, E.F., P.A. Topper, G.A. Varga, N. Brown, V. Blanes-Vidal, A.J. Heinrichs, T.L. Richard. R.E. Graves and V. Ishler, G.I. Zanton, and M.L. Moody. 2006. Reducing ammonia emission from dairy housing using nutritional strategies. In Proceedings Agricultural Air Quality Workshop, Washington DC. pp. 1229-1235. Williams, E.L., S.M. Rodriguez, D.C. Beitz, and S.S. Donkin. 2006. Effects of short-term glucagon administration of gluconeogenic enzymes in the liver of midlactation dairy cows. J. Dairy Sci. 89:693-703. Williams, E.L., S.M. Rodriguez, D.C. Beitz, and S.S. Donkin. 2005. Effects of short-term glucagon administration on gluconeogenic enzymes in the liver of mid-lactation dairy cows. J. Dairy Sci. 89:693-703. Williams, E. L., M. M. Pickett, G. A. Varga, and S. S. Donkin. 2006. Effect of dietary carbohydrate and monensin on expression of gluconeogenic enzymes in liver of transition dairy cows. J. Anim. Sci. (In Press). Book chapters and reviews during 2006 Bequette, B.J., Sunny, N.E., El-Kadi, S.W., & Owens, S.L. (2006) Application of stable isotopes and mass isotopomer distribution analysis to the study of intermediary metabolism of nutrients. J. Anim. Sci. 84(E. Suppl.):E50-E59. (Invited Review). Boston, R. C. and M. D. Hanigan. (2006). Segmented, constrained, nonlinear, multi-objective, dynamic optimization methodology applied to the dairy cow ration formulation problem in a situation where some of the constraints may be discontinuous. In: J. Dijkstra (Ed.) Modelling Nutrient Utilization in Farm Animals. Wageningen. pp 257-274. Firkins, J.L. and Z. Yu. 2006. Characterisation and quantification of the microbial populations of the rumen. Pages 19-54 in Ruminant Physiology, Digestion, Metabolism and Impact of Nutrition on Gene Expression, Immunology and Stress. K. Sejrsen, T. Hvelplund, and M.O. Nielsen, eds. Wageningen Academic Publishers, Wageningen, The Netherlands. Hanigan, M. D., H. G. Bateman, J. G. Fadel, J. P. McNamara, and N. E. Smith. (2006). An ingredient-based input scheme for Molly. In: J. Dijkstra (Ed.) Modelling Nutrient Utilization in Farm Animals. Wageningen. pp. 328-348. Hanigan, M. D., H. G. Bateman, J. G. Fadel, J. P. McNamara, and N. E. Smith. 2006. An ingredient-based input scheme for Molly. In: Nutrient digestion and utilization in farm animals: Modelling Approaches. ed. E. Kebreab, J. Dijkstra, A. Bannink, W. J. J. Gerrits, and J. France. CAB Publishing. p 328-348. Non-refereed publications during 2006 Bequette, B. Can we define nutrient requirements by following the metabolic highways of macronutrient use? Nutritional Sciences Series lecture, The Ohio State University (Columbus, OH) (May 20, 2005). Bequette, B. Mammary Gland Requirements. Eleventh DISCOVER Conference on Food Animal Agriculture: Amino Acid Requirements of Dairy Cows. Nashville, IN (August 28-31, 2005). Bequette, B. Mass Isotopomer Distribution Analysis for Studying Intermediary Macronutrient Metabolism. FASS Joint Meeting Symposium Stable Isotope Tracer Techniques for Non-ruminant Nutrition Research and Their Practical Applications, Cincinnati, OH, (July 26, 2005). Bequette, B. Reducing nitrogen excretion in ruminants: The potential to increase urea recycling. 3rd Mid-Atlantic Nutrition Conference, Timmonium, MD, (March 24, 2005). Bequette, B. Regulation of key metabolic processes in lactation. FASS Joint Meeting Symposium Exploring the Boundaries of Efficiency in Lactation: Metabolic Relationships in Supply of Nutrients in Lactating Cows (co-presentation with S. Donkin, Purdue), Cincinnati, OH, (July 25, 2005) Bequette, B. The roles of amino acids in milk yield and components. 17th Florida Ruminant Nutrition Symposium. Gainesville, FL. (February 1-2, 2006). Hill, M., R. Schlotterbeck, J. Aldrich, and G. Bateman. True or false? Feeding calves accurately is easy. Hoards Dairyman July 10, 2006. pp. 480. Ipharraguerre, I.R., and J.H. Clark. 2006. Dairy Cow Response to Sources and amounts of Supplemental Protein. Illinois Dairy Report. Pp. 11-15. Ipharraguerre, I.R., and J.H. Clark. 2006. Effects of Source of Supplemental Protein on Nitrogen Passage to the Small Intestine. Illinois Dairy Report. Pp. 16-20. Ishler, V. and G. A. Varga. 2005. How to use NDF digestibility information in ration balancing. Hoards Dairyman. Osman, M., N. Mehyar, G. Bobe, J. Coetzee, and D. Beitz. 2006. Acute effects of subcutaneous injection of glucagon and/or oral administration of glycerol on blood metabolites and hormones of Holstein dairy cows affected with fatty liver disease. A.S. Leaflet R2090. ISU Animal Industry Report. Richard, T., E. Wheeler, and G .A. Varga. 2005. Strategies for reducing gas emissions from dairy farms. Dairy Nutrition Conference, Grantville, PA. Varga, G. A. 2006. Things to look for to determine if you are doing a good job with emphasis on transition cow and early lactation. Feed Compounder, January. Seminars and Invited Presentations during 2006 Stern, M. D., A. Bach and S. Calsamiglia. 2005. New concepts in protein nutrition of ruminant animals. Proc. XII Biennial Congress of the Mexican Assoc. of Specialists in Anim. Nutr. (AMENA). Pages 1-25. Stern, M. D., A. Bach and S. Calsamiglia. 2006. New concepts in protein nutrition of ruminants. Proc. 21st Ann. Southwest Nutr. & Management Conf. Proc. p. 45-66. Published abstracts during 2006 Arieli, A., C. M. Martinez, T. W. Cassidy, and G. A. Varga. 2006. Effects of concentration and duration of Rumensin application on milk production efficiency in multiparous Holstein cows. J. Dairy Sci. 89:126 Abdelqader, M. M., A. R. Hippen, D. J. Schingoethe, K. F. Kalscheur, K. Karges, M. L. Gibson. 2006. Corn germ from ethanol production as an energy supplement for lactating dairy cows. J. Dairy Sci. 89(Suppl 1):156 (abstr). Bach, A., S. Calsamiglia and M. D. Stern. 2005. Nitrogen metabolism in the rumen. J. Dairy Sci. 88 (E. Suppl.).E9-E21. Bequette, B.J., Owens, S.L., El-Kadi, S.W., Sunny, N.E., & Shamay, A. (2005) Use of 13C-mass isotope distribution analysis (MIDA) to define precursors for lactose and amino acid synthesis by bovine mammary explants. J. Dairy Sci. 88(Suppl. 1):289. Bionaz, M., E. Shirk, J. P. Vanden Heuvel, C. R. Baumrucker, E. Block, and G. A. Varga. 2006. Treatment of Madin-Darby Bovine Kidney cells with fatty acid PPAR agonists. J. Dairy Sci. 89:335 Bionaz, M., C. R. Baumrucker, J. P. Vanden Heuvel, E. Block, G. A. Varga. 2006. Characterization of Madin-Darby Bovine Kidney cell line for PPARs. J. Dairy Sci. 89:335 Brown, A.W., M.M. Bohan, N. Mehyar, A.H. Trenkle, and D.C. Beitz. 2006. Effects of TNF-alpha as a simulated stressor on adipose and liver tissues from rats fed varying diets. FASEB J. 20:A126. Brown, N., V. Ishler, R. Chung, T. Cassidy, K. Hyler and G. A.Varga. 2005. Effect of forage processing and corn particle size on milk production and composition, and nutrient digestibility for high producing Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 99. Chung, Y. H., T. W. Cassidy, I. D. Girard, P. Cavassini and G. A. Varga. 2005. Effects of rumen protected choline and dry propylene glycol on production responses of periparturient Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 61 Chung, Y.-H., T. W. Cassidy, I. D. Girard, P. Cavassini, and G. A. Varga. 2005. Effects of rumen protected choline and dry propylene glycol on feed intake and blood metabolites of Holstein dairy cows. J. Dairy Sci. 88 (Suppl 1): 61 El-Kadi, S., Baldwin, R., VI, Sunny, N., Owens, S.L., & Bequette, B.J.. (2005) Postruminal protein infusion increases leucine use by the gastrointestinal tract of sheep while glucose utilization remains unchanged. J. Anim. Sci. 83 (Suppl. 1):128. Firkins, J. L., A. N. Hristov, M. B. Hall, and G. A. Varga. 2005. Integration of ruminal metabolism in dairy cattle. J. Dairy Sci. 88 (Suppl 1): 124. Firkins, J.L. 2006. Ruminal nitrogen metabolism: The current nutritional outlook. J. Dairy Sci. 89 (Suppl. 1):153. Firkins, J.L., A.N. Hristov, M.B. Hall, G.A. Varga, and N.R. St-Pierre. 2006. Integration of ruminal metabolism in dairy cattle. J. Dairy Sci. 89 (E. Suppl.):E31-E51. Galbreath, C.W., M.R. ONeil, J.D. Kirsch, J.W. Schroeder, K.G. Odde, G.P. Lardy, K.A. Vonnahme. 2006. Effect of feeding flax or linseed meal on progesterone clearance rate in ovariectomized ewes. J. Anim. Sci. (Abstr.). Girard, C. L., Y.-H. Chung, and G.A.Varga. 2006. Effects of rumen protected choline and dry propylene glycol supplements on plasma concentrations of folates and vitamin B12 in periparturient Holstein dairy cows. J. Dairy Sci.89:230. Hanigan, M. D., H. G. Bateman, J. G. Fadel, and J. P. McNamara. (2006). Metabolic models of ruminant metabolism: recent improvements and current status, J. Dairy Sci. E Suppl: E52-E64. Hanigan, M. D., H. G. Bateman, J. G. Fadel, and J. P. McNamara. 2006. Metabolic Models of Ruminant Metabolism: Recent Improvements and Current Status. J. Dairy Sci. 89:E52-E64. Hanigan, M. D., H. G. Bateman, J. G. Fadel, J. P. McNamara. 2006. Metabolic models of ruminant metabolism: recent improvements and current status. Journal of Dairy Science. 89 (E. Suppl.): E52-E64. Hill, T. J. Aldrich, H. Bateman, and R. Schlotterbeck. 2006. Effect of altering theoretical rumen undegraded soybean protein in a calf starter. J. Dairy Sci. 89(Suppl. 1): 437 (Abstr.). Hill, T., J. Aldrich, H. Bateman, and R. Schlotterbeck. 2006. Effect of altering theoretical rumen degraded and metabolizable protein in a calf starter. J. Dairy Sci. 89(Suppl. 1): 437 (Abstr.). Hristov, A.N., L. Campbell, and J. H. Harrison. 2006. Evolution of 15N abundance in cattle manure in relation to cumulative ammonia losses. J. Dairy Sci. 89 (Suppl. 1):357. Kadegowda, A. K. G., L. S. Piperova, and R. A. Erdman Principal component and multivariate analysis of milk fatty acid composition data from experiments designed to induce dietary milk fat depression in lactating cows. 2005. J. Dairy Sci. Vol. 88(Suppl. 1):176. Karnati, S.K.R., C.V.D.M. Ribeiro, J.T. Sylvester, and J.L. Firkins. 2006. Inhibition of methane synthesis on biohydrogenation in the presence or absence of protozoa in continuous culture. J. Dairy Sci. 89(Suppl. 1):127. Karnati, S.K.R., J.T. Sylvester, L.E. Gilligan, and J.L. Firkins. 2006. Manipulation of fermentation profile and methane production with microbial inhibitors and protozoal retention in continuous culture. J. Dairy Sci. 89(Suppl. 1):127-128. Linke, P. L., A. R. Hippen, K. F. Kalscheur, D. J. Schingoethe 2006. Glycerol from soy diesel production as a feed supplement to lactating dairy cows. J. Dairy Sci. 89:1872 (abstr). Loor, J. J., L. Piperova, R. E. Everts, S. L. Rodriguez-Zas, J. K. Drackley, R. A. Erdman, and H. A. Lewin. 2005. Mammary gene expression profiling in cows fed a milk-fat depressing diet using a bovine 13,000 oligonucleotide microarray. J. Dairy Sci. 88(Suppl. 1):120. Markantonatos, X., Y. Aharoni, T. Cassidy, R. K. McGuffey, L. F. Richardson, and G. A.Varga. 2006. A simulation model to integrate ruminal Volatile Fatty Acids (VFA) and blood glucose metabolism in transition dairy cows under steady state conditions. J. Dairy Sci. 89:72. Mpapho, G. S., A. R. Hippen, K. F. Kalscheur, D. J. Schingoethe 2006. Lactational performance of dairy cows fed wet corn distillers grains for the entire lactation. J. Dairy Sci. 89 (Suppl 1):1871 (abstr). Nester, P.L., J W. Schroeder, K.A. Vonnahme, M.L. Bauer, W.L. Keller, D. E. Schimek. Altering milk production and composition of early lactation dairy cows fed flax seed. J. Dairy Sci. (Abstr.). Oelker, E.R., C. Reveneau, and J.L. Firkins. 2006. Effects of molasses and monensin in alfalfa hay or corn silage diets on rumen fermentation, total digestibility and milk production in Holstein cows. J. Dairy Sci. 89(Suppl.1):127. Osman, M.A., N.A. Mehyar, G. Bobe, J.F. Coetzee, D.C. Beitz, and K. Koehler. 2006. Acute effects of subcutaneous injections of glucagon and/or oral administration of glycerol on blood metabolites and hormones of dairy cows affected with fatty liver disease. J. Anim. Sci. 84(Suppl. 1)/J. Dairy Sci. 89(Suppl. 1):266. Petersen, A.B., Baldwin, R., VI, Bequette, B.J., and Kohn, R.A. (2006) Effect of ruminally degraded protein source on microbial protein flow in Holstein cows. J. Dairy Sci. 89 (Suppl. 1): p.142. Riasi, A., M.D. Stern, M. Danesh Mesgaran, M.J. Ruiz Moreno. 2005. Ruminal and post ruminal crude protein digestion of halophyte forages (Kochia scoparia, Atriplex domorphostegia) determined by various procedures. J. Dairy Sci. (Suppl. 1) 88:383. Stern, M. D., M. R. Moreno, M. O. Tapia, M. J. Murphy, G. I. Crawford and K. Nelsen. 2006. Studies using continuous culture fermenters and a three-step in situ/in vitro procedure to estimate protein metabolism in ruminants Stern, M.D. T. K. Miller-Webster, W. H. Hoover, M. Ruiz Moreno, C. A. Macgregor. 2005. Effects of soy gum application to soybean meal on protein degradation by ruminal microbes and intestinal protein digestion. J. Animal Sci. (Suppl. 1) 83:90. Stern, M.D., M.R. Moreno and C.A. Macgregor. 2005. Effects of various methods used to process soybean meal on protein digestion in the rumen and small intestine. 2005 Conference on Gastrointestinal Function, Chicago, IL. Volume 2:24. Thomas, M., A. R. Hippen, K. F. Kalscheur, D. J. Schingoethe 2006. Growth and performance of Holstein dairy calves fed distillers grains. J. Dairy Sci. 89 (Suppl 1):1864 (abstr). Thomas, M., A. R. Hippen, K. F. Kalscheur, D. J. Schingoethe 2006. Ruminal development in Holstein dairy calves fed distillers grains. J. Dairy Sci. 89 (Suppl 1):437 (abstr). Ungerfeld, E., Bequette, B.J., Owens, S.L., & Kohn, R. (2005) Measurement of volatile fatty acid interconversion as a means to study the role of thermodynamics in the control of fermentation. J. Dairy Sci. (Suppl. 1) Van Saun, R. J., A. Todd, G.A. Varga. 2005. Serum Mineral Concentrations and Risk of Periparturient Disease. Amer. Assoc. Bov. Pract. Williams, E.L., S. Rodriguez, D.C. Beitz, and S.S. Donkin. 2005. Effects of short-term glucagon administration on gluconeogenic enzymes in the liver of mid-lactation dairy cows. J. Dairy Sci. 88 (Suppl. 1)/J. Anim. Sci. 83 (Suppl. 1):79. Theses and Dissertations El-Kadi, S.W. 2006. REGULATION OF MACRONUTRIENT METABOLISM BY THE GASTROINTESTINAL TRACT OF RUMINANTS. PhD dissertation. University of Maryland, pp. 152. Thomas, M. 2006. Growth, rumen development, and metabolism of holstein calves fed distillers grains. M.S. Thesis, South Dakota State University, Brookings, 80 pp. Prepared by A. R. Hippen at South Dakota State University (arnold.hippen@sdstate.edu)

Impact Statements

Objective 1:1. Mechanism for metabolic responses to ruminally-protected choline and propylene glycol are being elucidated to aid in the prevention of metabolic disorders in dairy cows. (PA) 2. The role of monensin in increased feed efficiency is being described. (PA) 3. An in vitro model for study of PPAR in bovine liver has been described for use in experiments describing energy metabolism in transition dairy cows. (PA)
4. Determination of fat content in distillers grains has been demonstrated to be highly variable by extraction methods. Use of methods for quantification of fatty acids is recommended. (WI) 5. Milk production of cows fed DG with high quality protein was not improved over that from cows fed DG alone.(WI) 6. As much as 2.5% of diet DM in the form of oil from corn germ can be added to lactating cow diets with no adverse effects on milk fat production or percentage. (SD)
7. Distillers grains can be included in calf diets at up to 28% of diet DM. At 56% of diet DM, indications are that ruminal development may be affected decreasing feeding efficiency. (SD) 8. Greater use of flax in the nutrition of dairy and beef cattle will support promotional efforts of flax growers. (ND) 9. Refined methods for in-situ and in-vitro estimations of protein digestibility have been demonstrated to more fully characterize protein fractions of feedstuffs. (MN)
10. The 15N abundance of the ammonia emitted from cattle manure during storage is relatively constant and ´15N of aged manure could potentially be used to predict ammonia emissions from cattle manure.(ID) 11. Sugar supplementation might require urea to support microbial protein synthesis in corn silage diets balanced for moderate CP especially if monensin is fed. (OH) 12. The role of ruminal protozoa and methanogen inhibitors in biohydrogenation of fatty acids has been described, allowing refinement of methods for feeding to increase milk CLA content. (OH)
13. Leafy and nutrient dense corn varieties have similar value to conventional hybrids when fed to lactating dairy cows. (IL)
Objective 2:1. The role of substrate for regulation of carbon flux into gluconeogenic pathways is being characterized. (MD) 2. Studies of urea cycling demonstrate the relative impacts of GIT transfer and rumen microbial N capture on nitrogen efficiency in ruminants. (MD) 3. Principle component analysis and microarray have been demonstrated as viable techniques for characterization of milk fat synthesis in dairy cows (MD)
4. Body weights and condition of lactating cows are increased with inclusion of distillers grains in diets demonstrating underestimation of energy values of distillers grains by NRC 2001. (SD) 5. Postpartal administration of glucagon causes adjustment in energy status so that accumulation of lipid in liver during the early postpartal period is diminished and thus improves cow health and thus profitability of the dairy enterprise. (IA) 6. Evaluation of protein requirements for lactating cows indicates that current NRC RDP requirements may be overstated. (VA)
7. Cell lines containing promoters for bovine PC will serve as reagents to determine the effects of combination of nutrients and hormones on expression of the gene and identify potential bovine specific promoter response elements and binding proteins.(IN) 8. Phase feeding may allow lower total CP to be fed to lactating dairy cows while maintaining milk production. (AL) 9. Identification of cows that exhibit increased efficiency of nitrogen use by genotype is a subject of ongoing research that could have a tremendous impact on the emissions of ammonia from dairy farms. (MI)
Objective 3:1. Models for nutrient and economic efficiencies of rearing young stock are being developed. (Akey) 2. Revisions to the representation of mammary activity in the Molly cow model have improved its ability to predict milk yield in response to varying nutritional states and to predict body weight loss and gain. (VA)
3. Information was provided to dairy managers and dairy nutrition consultants to consider less compositional analyses when formulating rations and rely more on library values. This approach would save the producer money and minimize environmental impacts of the chemical wastes generated from these chemical analyses. (CA)

Date of Annual Report: 01/23/2008

Report Information

Annual Meeting Dates: 10/22/2007 - 10/23/2007
Period the Report Covers: 10/01/2003 - 09/01/2007

Participants

McNamara, John (mcnamara@wsu.edu) - Washington State University
Armentano, Louis (learment@wisc.edu) - University of Wisconsin
Hannigan, Mark (mhanigan@vt.edu) - Virginia Polytechnic Institute and State University
Donkin, Shawn (sdonkin@purdue.edu) - Purdue
Bequette, Brian (bbequett@umd.edu) - University of Maryland
Schroeder, J. W. (JW.Schroeder@ndsu.edu) - North Dakota State University
Firkins, Jeffrey (firkins.1@osu.edu) The Ohio State University
Hippen, Arnold (arnold.hippen@sdstate.edu) - South Dakota State University
Bradford, Barry (bbradford@ksu.edu) - Kansas State University
Bateman, Gale (gbateman@akey.com)
Stern, Marshall (stern002@umn.edu) University of Minnesota
Cummins, Keith (kcummins@acesag.aunurn.edu) Auburn University
Fadel, James (jgfadel@ucdavis.edu) University of California - Davis

AA,David Benfield (benfield.2@osu.edu)- The Ohio State University, joined the group by phone conference.

Participants submitted written report but not present:
Beitz, Donald (dcbeitz@iastate.edu) - Iowa State University
Erdman, Richard (rerdman@umd.edu) - University of Maryland
VandeHaar, Micheal (mikevh@msu.edu) - Michigan State University
Varga, Gabriella (gvarga@psu.edu) Pennsylvania State University

Brief Summary of Minutes

Attached please find the summary of minutes of annual meeting.

Minutes Attachment:

Attachment

Accomplishments

Summary of NC 1009 5 year Accomplishments and Impacts: The need as indicated by stakeholders. Over 55% of the calcium, 17% of the protein, and 15% of the energy in the US diet are supplied by dairy products; thus, the US consumer is a major stakeholder for the NC-1009 committee. Consumers want dairy products that are safe and inexpensive, but increasingly they also want an environmentally friendly dairy industry that promotes animal well-being. Recently, attention has been given to bioactive molecules in milk (in addition to Calcium) such as conjugated linoleic acids. Yet at its core the NC 1009 committee functions to do basic and applied research on the feeding and nutritional biology of dairy cattle. Major stakeholders include other scientists, practicing nutritionists, veterinarians, and farmers. The needs of these stakeholders have been addressed by the Food Animal Integrated Research group in the FAIR 2002 document. The goals of FAIR 2002 are to strengthen global competitiveness, enhance human nutrition, protect animal health, improve food safety and public health, ensure environmental quality, and promote animal well-being. Because feed inputs are a major determinant of milk yield, cow health, feed efficiency, profitability, and waste output, the work of the NC-1009 committee is critical for most of these goals. The concentration of dairy animals into larger units is an established and continuing trend. This concentration makes some waste management issues more prominent but also more manageable. The importance of our work. Natural resources are used efficiently when milk production per unit feed and per cow is high. To efficiently produce milk, a cow must have a well-developed mammary gland and be able to supply the gland with the nutrients it needs. Nutrition in the first year of life affects mammary gland development, and nutrition around the time of calving and throughout lactation has a major effect on the health, productivity, and efficiency of cows. Feeding for optimal nutrient intake requires not only the provision of the necessary nutrients for milk production but also consideration to the effects of diet on mammary capacity and on appetite, health, and metabolic regulation of the cow. Because feed costs account for half of all costs on a dairy farm, nutrition also significantly impacts farm expenses. The NC-1009 committee considers all of these factors for optimal feeding. For example, if we could maintain current milk production while feeding diets with 4 percentage units less total protein, we would decrease N losses to the environment in the US by 470,000 metric tons per year and save US dairy farmers $1 billion per year in feed costs. This type of progress only can be made if we take an integrated approach, with the use of mechanistic bio-mathematical models that accurately describe metabolism and production of cows. Integration of results. This committee has a proven track record of making significant impacts in our knowledge dairy cattle nutrition and metabolism and in the way that dairy cattle are fed and managed nationwide. We use the same approach that has proven effective in the past: that is to challenge and refine our models of dairy nutrition and metabolism. Computer-based, mechanistic, and quantitative metabolic models are useful in two ways: first, they help us determine critical needs in research and second they enable practical improvements in dairy cow feeding. Critical research needs are determined by using existing data from NC-1009 members or conducting new experiments to test model predictions of physiological responses to experimental diets. Examples of such responses include, rumen pH, microbial growth and function; alterations in gene expression and hormonal release of organs such as the adipose tissue; and alterations in milk fatty acid compositions. By challenging our working models in this way, we identify shortcomings that then become the basis for developing new testable hypotheses for further experimentation. Results from new experiments are incorporated into the models, and they are challenged again for further refinement. Thus, we continue to build our models so they are more mechanistic, quantitative, and accurate. These qualities enable us to improve practical feeding recommendations for dairy cattle in a variety of environmental and feeding conditions. Need for Cooperative Work. Important and complex problems require coordinated effort of many personnel. Considerable progress has been made in dairy nutrition, but practical problems remain and no single research group has the skills and resources needed to solve them alone. Only through cooperation can State Experiment Stations address the complex interactions among feed supply, nutrient use, genetic capability, and milk composition. Our committee is comprised of dairy scientists with a broad base of specialties that encompass feed analysis, feeding management, ruminal microbial metabolism, intestinal digestion, physiology and metabolism of splanchnic, adipose, muscle, and mammary tissues, endocrine regulation, molecular and cellular biology, and mathematical modeling. Furthermore, in testing and refining nutrition models for the whole country, we must consider the variation in forages and environment that exist among regions. Thus, we have scientists from every dairy region in the country. In addition, the explosion of new information in genomics, gene expression, gene array work, metabolomics and proteomics requires that we integrate this knowledge into our understanding of metabolic efficiency. Cooperation among stations is required to deal with this information and to solve problems, and will have a national impact in understanding the complex interrelationships of nutrient digestion and metabolism in lactating dairy cows and to apply this knowledge. Impacts on Science and Other Impacts. This project exemplifies the proven effectiveness of the cooperative regional approach. As detailed in the "Related Current and Previous Work" section below, results of this cooperative effort have become benchmarks of scientific progress and have led to practical feeding recommendations used worldwide. Project Leaders for the NC-185 regional project have received numerous awards for research, both basic and practical, from the American Dairy Science Association, the American Society of Animal Sciences, and industry groups. Most of the Project Leaders are in continuous demand as speakers for scientific and industry conferences in nutrition. The impact on basic and practical nutrition from Project Leaders has been profound in the areas of starch and protein chemistry and nutrition, feed processing, nutrient metabolism, and lactation biology. This group provided a major contribution to the 2001 version of the National Research Councils (NRC's) Nutrient Requirements of Dairy Cattle. Four of the 10 scientists on the NRC panel were from the NC-185 committee, and a significant portion of the data used in the latest edition came from NC-1009 committee members. In 2005, the group presented a symposium at ADSA/FASS on regulation of nutrient use in dairy cattle (references are in bibliography). Thus, this committee has had a major impact on improving the biological, economical, and environmental efficiency of the US dairy industry. Summary of progress: One overriding goal in feeding cattle is to find the optimal combination of chemical and physical properties of feeds that provides the proper amount and balance of absorbed nutrients to match the ability given by the genotype of the cow or herd. This is a major challenge because of the tremendous variety of feedstuffs available, their complexity of interactions among feed particles, nutrients and organisms in the rumen, genetic variance within and among herds, and the rapidly changing nutrient requirements of a cow around the time of parturition. The amount and profile of absorbed nutrients in dairy cattle are a function of rumen fermentation and intestinal digestion. Feed particles and microbes that escape the rumen can be digested in the small intestine to produce amino acids, monosaccharides, and lipids for absorption. The chemical and physical properties of feeds determine the availability of nutrients critical to the production of milk and milk components in a variety of ways. For example, the chemical composition (including total protein, nonprotein nitrogen, amino acid balance, organic acids, lipids, fiber, and non-fiber carbohydrate) dictates directly the availability of nutrients to support rumen microbial growth and the absorbed nutrients available to the animal to support milk synthesis. The physical properties of feeds, either inherent in the plant structure or altered by various processing methods, alters degradability in the rumen, and thus determines the proportion of feed fermented and used for rumen microbial growth and the proportion that passes to the small intestine. The cow is a fully integrated system in which one, even minor, change in nutrient input may lead to a variety of downstream events that alters function at the animal level. Since the last revision, we now understand more fully that this also includes changes in gene expression, and endocrine responses that were unknown or just discovered 5 years ago (IGF-1, leptin and ghrelin from the adipose tissue, for example). Dietary carbohydrate fractions differ in the profiles of glucogenic and lipogenic metabolites they yield from ruminal and intestinal digestion. The amount and types of carbohydrates also impact rumen pH, which, in turn, alters fermentation and can alter the yield of nutrients, even amino acids, for absorption. Thus the various carbohydrate fractions have differential effects on the yield and composition of milk. Recent improvements in methods will allow more accurate prediction of optimal amounts and ruminal availability of non-fiber carbohydrates for efficient production of milk and milk components. More importantly, because of the integrative modeling approach of this committee, we have a quantitative knowledge of the maximal percentage contribution of these fractions to overall yield and efficiency on different diets, and can move on to further work. The amount and balance of absorbed amino acids also helps determine milk yield, not only milk protein synthesis. This availability of amino acids, in turn, is a function of the amount of feed protein which passes undegraded through the rumen and the amount of ruminally synthesized microbial protein that reaches the small intestine. Because microbial protein has a better amino acid profile than many feed proteins, this remains an important area of study. Microbial protein yield is also a function of the amount and type of organic matter fermented. Thus, microbial protein yield varies by source of carbohydrate and protein, and rate of fermentation. This is a classic example of the need for an integrated approach to dairy cattle nutrition-we must continue to design experiments across state lines that allow a full scope of study of the key variables. We need to continue to build a comprehensive model that explicitly includes these types of interactions. Synthesis of milk and milk components is a function of both the synthetic potential of the mammary gland and the supply of metabolites to the mammary gland. Supply of metabolites comes from dietary components, some of which are modified in other tissues, and from mobilization of body lipids and amino acids. There is an interaction between metabolism of body tissues, the supply of dietary nutrients and the milk production potential of the cow (as well as other animals) which has been recognized for quite some time which provide an extreme range of response of animals to even the same diet. While many dairy scientists have been slow to recognize the importance of these interactions, several stations in this project have been studying these interactions across a range of diets, genetic potentials, and stages of lactation (AL, CA, IA, IN, KS, MI, PA,WA and more recently, OH, MD, VA, VT, ). Data has been used to refine our feeding recommendations on a wide variety of feedstuffs. New concepts on the interactions of nutrition and gene expression is exemplified with work just two stations: IN, at which new information on molecular control of expression of the enzymes that control gluconeogenesis in the liver are showing specific differences between the cow and other animals. At WA, work with supplemental chromium, a nutrient known to be required for many years, a positive feed intake and milk production response was obtained with supplemental chromium, along with a reduction in lipolysis and an increase in lipogenesis in adipose tissue, removing the negative effects of fatty acid mobilization on feed intake in early lactation. Many nutritionists have now recognized that we cannot do relevant nutritional research with integrating this work with genetics and gene expression. Many nutrients are now known to affect gene expression in several organs, which then alters the animal response to the diet or further changes in the diet. Newer additions to the committee (VT, MD, OH) as well as adapting previous members (IN, MI, AL, WA) have begun serious efforts in identifying genetic responses to diet and to lactation. This work falls presently into the basic aspect-providing hard data to other scientists and advanced professionals on the key interactions of genetics and diet. This holds future promise in even more efficient feeding management and breeding programs. Major advancements have occurred in our knowledge of the interaction of metabolism and the endocrine system. Studies at AL, IN, and MI, in collaboration with other NC-1009 members, have illustrated the role of nutrition in the IGF-I system of dairy cattle. Studies at IA have illustrated the role of glucagon in lipid metabolism and shown its potential benefit as a treatment for fatty liver. Work has been done on the role of leptin, which is known to alter feed intake, yet a clear understanding of the physiological role of leptin in lactation has been elusive. If we are to improve the accuracy and precision of predicting nutrient use, we must continue to improve mechanistic, dynamic models of metabolism. The newer Dairy Nutrient Requirements book (NRC, 2001) was based in large part on data from this committee. In the 5 years since its publication, it has gained great respect in the industry. However, the process of revision of this document, and the model within it, also pointed out many of the shortcomings in our current knowledge base. The new version is limited especially in predicting dietary nutrient interactions, which consequently hamper our ability to predict rumen microbial metabolism and microbial protein yield and therefore responses to rumen-undegraded protein, carbohydrate, and fat supplements. Other significant limitations are the ability to predict short term versus long-term nutritional responses and changes in body fat and protein use. More mechanistic modeling of the metabolism of the lactating dairy cow will allow for evaluation of these interactions. The most comprehensive mechanistic and dynamic model of metabolism in the dairy cow is called 'Molly', developed at CA with inputs from most NC-185 members. Members of this project also have been instrumental in developing the new NRC model (NRC, 2001), which serves as the standard for dairy ration formulation and evaluation in the US. These different computer nutrition programs are currently in use for predicting nutrient requirements and productivity of lactating dairy cows. While all of these systems are soundly based on available data, all have weaknesses in the areas defined by Objectives 1 and 2. The rate of degradation of feedstuffs, the effect of various dietary carbohydrates on rumen fermentation and microbial protein synthesis, and quantitative data on metabolic interchanges among nutrients and body tissues limit the accuracy of these systems. New collaborative efforts by the NC-1009 project are needed to remove these inaccuracies. Molly is limited in its ability to describe the rapid changes in nutrient use that occur in early lactation and in predicting physiological responses to high feed intakes or diets with atypical amino acid, fiber, or starch contents. This is not surprising, given the paucity of these types of data when the model was originally constructed in the 1970 and 1980s. The modeling work done spurred new research into getting those data. Work done by a newer member of the committee (OH) was used to challenge Molly for its description of energy use in the viscera. Visceral metabolism can account for the majority of maintenance requirements and can be highly variable. Errors in the model reflected a lack of knowledge of visceral metabolism in early and mid lactation. Using data generated we challenged and improved the descriptions of energy use in the model, further increasing its utility in research and application (McNamara, 2005, 2006). Quantitative data are still needed on the supply of milk component precursors available under different metabolic and nutritional conditions, such as early lactation. Data also are needed on the metabolic interconversions of nutrients, such as the use of amino acids for gluconeogenesis and thus milk lactose synthesis, and the partitioning of body fat and fat derived from the diet or lipogenesis for milk fat synthesis. These data will enable further refinement of current nutrition recommendations and aid in interpretation of feeding experiments. Other Specific accomplishments: Reductions in feeding levels for ruminally degradable protein would reduce nitrogen losses in manure and improve animal efficiency. As ammonia emissions from manure are driven by the amount of urinary N deposited in manure, such changes would lead to reduced ammonia emissions from animal and manure storage facilities. Improved knowledge of the mechanisms that regulate milk protein synthesis will allow development of models that better predict the requirements for milk protein synthesis. This in turn will allow more refined estimates of N requirements and reduced safety margins in feeding systems. Such an outcome will also work to reduce ammonia emissions from animal and manures storage facilities. Phosphorus availability in the digestive tract is an important determinant of the amount that must be fed and the amount that is lost in feces. Model development has helped identify key aspects of P digestion that warrant further examination and must be considered in requirement models to achieve greater reductions in P feeding levels.(VA) This research evaluates the relationships between milk urea nitrogen, plasma urea nitrogen and urine urea nitrogen. Milk urea N can be a used to predict UUN excretion and may be extended to estimate NH3 emissions from dairy cattle manure because there is a strong relationship between UUN excretion and NH3 emissions. The information from this research can also be used to test metabolic models for urine urea excretion. (CA) Greater use of flax in the nutrition of dairy cattle can supplement lactation diets with not only protein and energy, but compliment the growing interest in designer foods with milk enriched with omega-3 and omega-6 from such grains as flax seed. Furthermore, preliminary evidence suggests that dairy cow fed flax also have improved reproductive health with improved pregnancy rates. It has been estimated that if dairy cow pregnancy rates could be increased, an estimated cost savings to the dairy enterprise of $8.73 per cow per year could be realized for every percentage unit gained. (ND)

Publications

Please see attached file for Refereed Publications

Publications Attachment:

Attachment

Impact Statements

OBJECTIVE 1: (1) Mechanism for metabolic responses to ruminally-protected choline and propylene glycol are being elucidated to aid in the prevention of metabolic disorders in dairy cows. (PA)
The role of Monessen in increased feed efficiency is being described. (PA)
An in vitro model for study of PPAR in bovine liver has been described for use in experiments describing energy metabolism in transition dairy cows. (PA)
Determination of fat content in distillers grains has been demonstrated to be highly variable by extraction methods. Use of methods for quantification of fatty acids is recommended. (WI)
Milk production of cows fed DG with high quality protein was not improved over that from cows fed DG alone.(WI)
As much as 2.5% of diet DM in the form of oil from corn germ can be added to lactating cow diets with no adverse effects on milk fat production or percentage. (SD)
Distillers grains can be included in calf diets at up to 28% of diet DM. At 56% of diet DM, indications are that ruminal development may be affected decreasing feeding efficiency. (SD)
Greater use of flax in the nutrition of dairy and beef cattle will support promotional efforts of flax growers. (ND)
Refined methods for in-situ and in-vitro estimations of protein digestibility have been demonstrated to more fully characterize protein fractions of feedstuffs. (MN)
The 15N abundance of the ammonia emitted from cattle manure during storage is relatively constant and ´15N of aged manure could potentially be used to predict ammonia emissions from cattle manure.(ID)
Sugar supplementation might require urea to support microbial protein synthesis in corn silage diets balanced for moderate CP especially if monensin is fed. (OH)
The role of ruminal protozoa and methanogen inhibitors in biohydrogenation of fatty acids has been described, allowing refinement of methods for feeding to increase milk CLA content. (OH)
Leafy and nutrient dense corn varieties have similar value to conventional hybrids when fed to lactating dairy cows. (IL)
OBJECTIVE 2: 1. The role of substrate for regulation of carbon flux into gluconeogenic pathways is being characterized. (MD)
2. Studies of urea cycling demonstrate the relative impacts of GIT transfer and rumen microbial N capture on nitrogen efficiency in ruminants. (MD)
3. Principle component analysis and microarray have been demonstrated as viable techniques for characterization of milk fat synthesis in dairy cows (MD)
4. Body weights and condition of lactating cows are increased with inclusion of distillers grains in diets demonstrating underestimation of energy values of distillers grains by NRC 2001. (SD)
5. Postpartal administration of glucagon causes adjustment in energy status so that accumulation of lipid in liver during the early postpartal period is diminished and thus improves cow health and thus profitability of the dairy enterprise. (IA)
6. Evaluation of protein requirements for lactating cows indicates that current NRC RDP requirements may be overstated. (VA)
7. Cell lines containing promoters for bovine PC will serve as reagents to determine the effects of combination of nutrients and hormones on expression of the gene and identify potential bovine specific promoter response elements and binding proteins.(IN)
8. Phase feeding may allow lower total CP to be fed to lactating dairy cows while maintaining milk production. (AL)
9. Identification of cows that exhibit increased efficiency of nitrogen use by genotype is a subject of ongoing research that could have a tremendous impact on the emissions of ammonia from dairy farms. (MI)
OBJECTIVE 3: 1. Models for nutrient and economic efficiencies of rearing young stock are being developed. (Akey)
2. Revisions to the representation of mammary activity in the Molly cow model have improved its ability to predict milk yield in response to varying nutritional states and to predict body weight loss and gain. (VA)
3. Information was provided to dairy managers and dairy nutrition consultants to consider less compositional analyses when formulating rations and rely more on library values. This approach would save the producer money and minimize environmental impacts of the chemical wastes generated from these chemical analyses. (CA)