Brief Summary of Minutes of Annual Meeting

NE 1024 Meeting Minutes 10/27 & 10/28 2008 Tillamook, Oregon Meeting began at 1:30 PM 10/27/08 Attending: Joe Harrison, Rhonda Miller, Dick Hegg, Mark Powell, Vinicius, Moreira, Michel Wattiaux, Mike Westendorf, Zhengxia Dou, Mike Murphy, Rich Muck, Stephen Herbert, Al Rotz, Jon Waith, Troy Downing, John Westra Guests: Andrew Sandeen, Mark Wustenburg First presentation: Mark Wustenburg Tillamook Creamery - Farmers coop started in 1909 120 coop members membership is limited to North Coast of OR  2 manufacturing facilities, 50 million pounds of cheese at Tillamook - 100 million pounds processed into cheese in eastern OR, 2/3 of which is from non-members  20,000 acres of tillable land, cool season grasses, high rainfall ~ 80 inches, graze March thru November, foster a higher level of Jersey milk due to need for cheese production - ~ 40 % Jerseys. Don't do a full pasteurization (thermalization), thus need to age cheese for 60 days, average dairy is 220 cows, 26,000 to 28,000 cows in Tillamook area, milk quality - 130,000 to 140,000 SCC in milk, environmental issues are significant consideration due to flood plain and coastal location, air quality concerns have been stimulated by larger eastern facilities, 60% of producers are > 65 yrs in age, larger scale pasture operations are difficult to implement, feed import into the area (from off-farm) is probably 75% for lactating cows, generally excess P in manure for crop production, all dairies are environmentally permitted. Second presentation - Al Rotz - Green house gases and carbon footprint Ammonia emissions, green house gases, and carbon footprint has been the focus for the past 2 years Seems to be a trend for increased GHGs in recent decades and associated with animal ag GHGs - Carbon dioxide, methane, and nitrous oxide Processed based model of sources and sinks Carbon fixed in pant, soil respiration, plant respiration, engine exhaust, animal respiration, manure on bran floor, and manure handling Methane emissions - enteric fermentation, manure on barn floor, manure storage, following manure application, feces from grazing Nitrous oxide - nitrification and denitrification, manure on barn floor and manure storage Secondary emissions - fuel, electricity, machinery, fertilizers, pesticides, seed, plastic Carbon footprint - sum of all GHGs per unit of production, include primary and secondary emissions Google - Dairy GHG, on Al's website DAFAGEM demonstrated For forages, on an inventory basis vs predicted as is done on IFSM Assume that farm is not sequestering carbon COMET-VR model of NRCS can be used for carbon sequestering No econ numbers in GHG model Production of cull cows (beef - meat) is not currently accounted for in calculations IFSM update Version 3.0 is about ready for release This version will have a GHG table State Reports WA - Harrison - K work, AD nutrients and pathogens, manure application and shallow ground water, effect of tillage WI - Powell - manure N capture and recycling Forage tannin impact Ammonia emissions Australia sabattic - accounting of nutrients on grazing dairies Rhonda Miller - Nutrient cycling in management intensive grazing systems Uneven distribution of nutrients, Deferred grazing and potential negative impacts on environment Michel Wattiaux - WI - Effect of diet CP on ammonia emissions Greater manure excretion when alfalfa silage was fed compared to corn silage Use of straw in manure storage will reduce ammonia emission N-Cycles software - collaboration with Canada - N and P - allows for optimizing based on soil nutrients Rich Muck - WI - Obj 1 - protein breakdown during ensiling, use of red clover, polyphenol oxidase enzyme, form quinones which inhibit protein breakdown, now have genetically modified alfalfa for test tube studies, now looking for grasses that have both PPO and substrates Effect of silage inoculants on animal performance, have used rumen in vitro methods, see the 3-5% animal improvement even when there are no silage fermentation effects Effect of silo type, bunker, bag, oxygen-limiting tower Vinicius Moreria - LA - Dairy wastewater treatment system evaluation, multi-stage parlor wastewater treatment system, Anaerobic, aerobic lagoons, and constructed wetland Then evaluated a 2 stage system vs 3 stage, eliminate the aerobic lagoon 3 stage system better at removing nitrogen and e-coli, fingerprinting demonstrated that e-coli in wetlands was from pigs and not cows Mike Westendorf - NJ - 90 dairies in NJ, lots of other livestock farms, developed nutrient management plan development software for small farms, Dou - PA - P form in dairy feces Pathogen survival - Salmonella Newport, E Coli 0157 Composting kills both within a day or so Integrated Management Program - NRCS CIG - Chesapeake Bay project Is there a best combo of home grown forages for a given farm International Chinese collaboration to strengthening relationship with Chinese dairy industry Mike Murphy - IL - Distillers grains work, separate DDGS and partition into different fractions, more and less fibrous fractions based on an air-gravity technique Stephen Herbert - AM - Systems approach for producers, cover crops, importance of fall planting date in capture of nitrate nitrogen, corn hybrid selection  early and late hybrids, pasture emphasis - what types of grass varieties are best in any given species, have evaluated the use of no till corn and then graze it. John Westra - Econ at LA - collaborates with Vinicius Admin Report - Dick Hegg National Institute of Food and Agriculture to replace CSREES Head will be an upper level political appointee, may have a better voice for food and ag Jon Waith - NH - Next year it would be time to begin rewrite How do we approach the re-write: need clarification of what is expected by review panel, does it have to center around IFSM, how different does it need to be, Next years meeting, should we meet with 1032 and 1025 in St Louis next September?????? - No Last Project rewrite - 1. Enhance systems Increase efficiency Decrease excretion 2. Enhance systems for reduced &&.. loss to Environment 3. Models - refinement and proofing, including profitability 4. Outreach tools Ideas for next proposal - 1)Temperate beef, Utah and MA - Grazing systems, Pasture based 2) Gaseous emissions, Green house gases, volatiles 3) Regional drivers of changes in the dairy industry in the future, what parts of the system should we focus on if we took an efficiency emphasis 4) Maybe efficiency focus needs to be viewed differently, not at cow level, but at farm scale 5) Use model as a tool to look at &&&&&&.. 6) Decision aid tools that are at a partial system (partial budget) scale 7) Organic dairy production 8) Pathogens and pharmaceuticals, endocrine disruptors 9) comparative evaluation of different regional dairy systems (economic, environmental, housing) 10) Maximizing home grown feed, carrying capacity Meeting focus - Rewrite project Meeting location - October 2009 Avoid early November (ASA) meetings Should we invite stakeholders? - NE pasture consortium, NRCS, EPA, NMPF, Secretary for 2009 - Mike Westendorf Chair - Joe Harrison

Objective 1, Section 1a. Nutrient uptake and nutritional value of crops. A study was initiated in the fall of 2004 to look at the relationship between dairy manure application to a grass field and nitrates in ground-water. Data indicated an initial increase in soil nitrate and shallow ground water nitrate associated with soil tillage. The 1-ft soil nitrate levels ranged from ~ 5 to 60 ppm and varied by year. Grass nitrogen yields ranged from ~ 159 to 209 kg per growing season. Shallow ground water nitrate increased in the first 5 months (Feb 05) to ~ 30 mg/liter, and decreased steadily to less than 10 mg/liter beginning in March 07. Managing the organic nitrogen in soil appears to play a major role in the concentrations of nitrate in shallow ground water. The focus of other research was on understanding how bacterial silage inoculants affect in vitro ruminal fermentation with the goal of discovering good hypotheses why silage inoculants improve rate of gain in growing cattle and milk production in lactating cattle. Analyses of silages produced in 2007 progressed but still are not complete. Preliminary results show some differences in amino acid composition of the soluble non-protein fraction of the silages. Larger grass plots were established to test the polyphenol oxidase system to protect protein during ensiling of grasses at pilot-scale. A process to remove P from liquid dairy manure was refined from manure after anaerobic digestion treatment. Results indicate that as much as 80% of P can be removed. Struvite (mg-N-P) that has been extracted from liquid dairy manure was shown to be a good source of nutrients for growth of corn and alfalfa. Section 1b. Herd Nutrient Utilization Strategies This trial compared milk yields of cows grazing either a perennial pasture type (kura clover/reed canary grass, (KRC)), or a short lived annual pasture (white clover/Italian ryegrass, WRG)) when managed by management intensive grazing. Twenty eight primiparous Holstein cows (89 DIM and, 535 kg BW), were randomly assigned to one of four-2.4 hectare paddocks. Two of the pastures were established with kura clover (Trifolium ambiguum Bieb, cv. Endura.) and low alkaloid reed canarygrass (Phalaris arundinacea L, cv.Palaton) in 1999. The KRC pastures contained approximately 50% reed canarygrass and 50% kura clover at initiation of this experiment in 2007. The other two pastures were seeded in the spring of 2007 with a mixture of white clover (Trifolium repens L. cv Kopu II) and Italian Ryegrass (Lolium perenne ssp. Multiflorum, cv Feast II). All pastures were managed to offer cows approximately 30 kg of forage DM per day. The daily grazing area was estimated according to the pasture availability and the number of cows in each paddock. Cows were allowed to graze approximately 20 h/d and were milked twice daily. Supplemental concentrate was provided daily after each milking (7.2 kg/cow/d). Pastures were initially stocked with 7 cows per paddock, but as the summer progressed and pasture growth declined, cows from each of the paddocks were removed to keep pasture availability constant and assure adequate supply of pasture. Pasture intake was estimated by difference in yield estimates from pasture quadrats clipped at a 5 cm stubble height before and after grazing. Pastures quality was high throughout the trial (41 +/- 1.6%, NDF, and 18 +/- 0.5%, CP). Milk yield/cow/d tended lower for JH than H (27.0, 29.8 kg/d, respectively p < 0.07) and 3.5% FCM was lower for JH than H ( 28.0, 30.0 kg/d respectively, p < 0.01). Milk fat percentage was similar for JH and H (3.6+/- 0.1%). Fat corrected milk yield by paddock was higher for H than JH (1349, 1187 kg 3.5%FCM/paddock/week respectively, p<0.05). Pasture DMI did not differ by breed (1133 kg DM/paddock/d). Grazing Holstein primiparous cows produced more milk from high quality pasture than Jersey-Holstein crossbreds. Breed had did not affect pasture intake, the advantage was due to higher production per cow of the Holsteins than the Jersey-Holstein crossbreds. Previous attempts to correlate near-infrared reflectance spectroscopy (NIRS) spectral data with in vitro NDF digestibility (ivNDFD) measures have yielded mixed results. The ability of NIRS to predict a nutrient parameter highly depends on the precision of the laboratory technique used as a reference procedure. The objective of this study was to determine if acceptable NIRS calibration equations for 24, 30, and 48 h NDF digestion measurements could be developed from a more precise in vitro NDF digestibility reference procedure. A set of 122 grasses and legumes were digested in vitro using the Goeser et al. (2008) ivNDFD technique. Three replications, with duplicate subsamples within replicate, were completed for each forage and time point combination. Following ivNDFD analysis, ground forage samples were scanned on a near-infrared reflectance spectrophotometer and spectral data was related to 24, 30, and 48 h NDF digestibility (NDFD, % of NDF) and digestible NDF (dNDF, % of DM) measurements as well as NDF (% of DM). Calibrations were computed using partial least squares regression techniques and calibration performance was evaluated based on the coefficient of determination (R2), the standard error of calibration (SEC), the standard error of cross validation (SECV), and 1 minus the variance ratio (1-VR). The R2, SEC, and SECV values of 48 h NDFD calibration indicated improved precision relative to prior research and no comparison could be made for earlier time points. The R2, SEC, and SECV values of dNDF calibrations were also improved relative to prior research. In conclusion, near-infrared reflectance spectroscopy spectral data was successfully related to in vitro NDFD and dNDF data, with greater precision than observed previously. The universal calibration equations developed are capable of precisely predicting 24, 30, and 48 h ivNDFD rapidly for a broad range of grass and legume samples. We are conducting animal work to refine the P requirements of lactating cows, growing heifers, and pre-weaned calves. In the first study, we published a peer reviewed paper on the results of a project focused on early lactation cows, evaluating the impact of dietary Ca on bone P resorption and replenishment throughout lactation. Methods used include total collection, bone biopsy, and monitoring serum markers of bone resorption and formation. We found that, contrary to our expectations, dietary Ca concentration had no effect on P retention or bone metabolism. However, first lactation cows had more active bone metabolism through the 140 d study. There was a switch from net bone resorption to formation after 35 d of lactation regardless of dietary Ca concentration. This information will help refine dietary mineral recommendations for dairy cows and ultimately reduce P excretion into the environment. Second, we are continuing our work on nutrient excretion and efficiency of nutrient utilization by growing heifers. We published the results of recent work on the effect of dietary forage content and byproduct utilization in bred heifers. We use total collection to monitor effects of treatment. Heifers limit-fed the low forage ration excreted three times as much urine and more total manure compared to those fed high forage and by-product rations. Excretion of nitrogen and phosphorus were not affected by diet. The current ASABE beef equations that predict manure DM excretion rather than wet manure excretion were better predictors of manure excretion observed in this study than were the dairy equations. We also completed research evaluating the effect of varying milk replacers in pre-weaned calves and published this paper. We found that calves fed a standard milk replacer ate more grain than heifers fed more nutrient-dense diets, but had poorest gain and greatest feces excretion. Addition of protein to standard milk replacer improved calf growth and nutrient retention; few additional benefits were observed with added fat. Compared to predicted values for mature cows, we calculate that 12,000 to 17,000 heifers would produce quantities of manure or manure nutrients similar to a concentrated animal feeding unit of 700 mature dairy cows. Finally, we continue work implementing intensive feed management practices on collaborator farms in Virginia, to improve whole farm nutrient balance. We are focused on practices such as improved forage quality, more frequent feed analysis, implementation of feed mixing and delivery tracking software, and reduced overfeeding. As part of this project, we are implementing an incentive payment program to reduce overfeeding of dietary P, with 200 farms enrolled in the project. OF farms completing 12 months of sampling, about half earned incentive payments because their dietary P approached targets. 69 farms have received a total of $90,000 in incentive payments to date. Comparison of P forms in feces of two dairy farms feeding different amount of P Fecal samples were obtained from two commercial dairy farms. Farm 1 had 283 milk cows producing 69 lb milk/c/d with diet P concentration of 0.50%; Farm 2 had 93 cows producing 69.3 lb milk/c/d with diet P concentration of 0.37%. Conventional fecal analysis results: (i) fecal total P concentration was 11.30 g/kg for farm 1 and 4.17 g/kg for farm 2. (ii) fecal water soluble P was 3.98 g/kg on farm 1 and 1.46 g/kg on farm 2. Comparison of P extractability (or recovery) by different extractants: Water extracted 35% of the total P, an acid extractant 100 mM Na acetate, pH 5.0 plus 20 mg Na dithionite/ml had a recovery of 84-100%, an alkaline extractant 0.025 M NaOH with 50 mM EDTA had a recovery of 80-100%. Liquid state 31P nuclear magnetic resonance spectroscopy (31P-NMR) results: (i) Water is not an effective extractant as several important P forms (phosphonate, IHP i.e., phytic acid, pyrophosphate, and polyphosphate) were missing in water extracts of samples from both farms. (ii) The slightly acid extractant NaAc performed equally well or even better than the traditional NaOH+EDTA extractant. Numerically, the amounts of orthophosphate, IHP, diesters, and polyphosphate were similar in the two extracts, whereas NaAc extracts had higher amounts of other monoesters and pyrophosphate as compared to the NaOH+EDTA extracts. (iii) Both NaAc and NaOH appeared to cause degradation of DNA and other diesters as there were greater amounts of these P compounds in the water extracts. (iv) The vast majority of total P in dairy feces existed as orthophosphate. Furthermore, orthophosphate accounted for a higher proportion of total P in the sample from Farm 1 (82 and 85%) than Farm 2 (64 and 72%). Objective 2: Evaluate and develop efficient animal, manure, and cropping systems for reduced nutrient flow, cycling, transformation and loss to the environment. One project evaluated pollutant abatement effectiveness of replacing second stage aerobic lagoon with smaller constructed wetlands. The Dairy Wastewater Treatment Evaluation System is a three-stage system composed of ANL, AEL, and three WLDs, replicated. The system was used to simultaneously compare and quantify treatment effectiveness of a control, three-stage system (ANL, AEL, WLDs) with a two-stage treatment (ANL, WLDs). Wastewater COD, solids, nutrients (TKN, TP), and coliforms were monitored at all stages in the system for 6 months. Treatment was applied 3 months to each replicate while the counterpart was maintained as control in a cross-over design. Statistical comparison was made among WLD effluents in different systems. Small difference in pollutant abatement between idle AELs and AELs continually receiving ANL effluent is attributed to the effectiveness of AELs in the complete system. Most treatment efficacies were significantly reduced when AELs were bypassed. The two stage system (ANL-WLD) performed at 65% of the control system (ANL-AEL-WLD). Constructed wetlands combined surface area represented 41% of the AELs. ANL-fed WLDs resulted in approximately 40% of the treatment efficacies of AEL, ranging from 1% for TKN to 49% for COD. Nitrogen removal was limited by decay of organic matter accumulated in WLDs receiving ANL effluent. A review of nutrient management tools for confinement and grazing-based dairy operations was completed. Generally, these tools quantify nutrient imports and exports at the farm scale, nutrient flows and use efficiencies at the component scale (i.e. feed, milk, manure, land-application, plant uptake) and soil fertility status and nutrient loss at the field or paddock scale. There is further scope to improve nutrient management tools so that they not only quantify nutrient balances on dairy farms, but also assist in identifying opportunities for enhanced nutrient use within farm components, and reduced nutrient losses. A study was conducted at the Pioneer system research farm, University of Wisconsin, Platteville. The 78-cow lactating herd was divided in two groups, each being allocated to either a recommended diet with 16.7 ± 1.3 % CP (DM basis) or an excess CP diet containing 1.5 units of CP above the REC diet (18.2 ± 1.5%). Total manure collection from each group was conducted by manual scrapping in seven months between February 2004 and January 2005. Manure samples collected at different time points were analyzed for N content. Monthly samples of all diet ingredients and milk were collected and analyzed for N content and milk urea nitrogen (MUN). Dry matter intake and milk yield was recorded to estimate N balance for each group of cows. Ammonia-N emission was estimated for each group of cows for each monthly sampling period by N mass balance (Nin  Nout) of the pen where they were allocated with the following equation: NH3-N emission = intake N + bedding N  milk N  scrapped manure N. Using the above equation, NH3-N emission was estimated assuming that other volatile N compounds were a negligible fraction of the total volatilized N during manure collection. Feeding excess dietary CP did not affect dry matter intake, milk production or milk composition. Wet manure excretion was higher when corn silage became unavailable and alfalfa silage was the only forage source in the diet (75 vs. 87kg/d per cow, respectively). On average NH3-N loss was 110 g/d per lactating cow, but ranged from 64 g/d to 178 g/d with no clear seasonal pattern. Milk urea nitrogen was weakly related with NH3-N volatilization; however there was a strong linear association between MUN, manure N excretion and dietary CP. By decreasing 1.5 unit of CP in the diet (16.5 to 18.0% of diet DM), we observed a 27% reduction in NH3-N emission (93 vs. 127 g/d per cow). A study in Utah examined nitrogen and phosphorus cycling in both a traditional management intensive grazing system, and in a deferred grazing system. To replicate a system producers would use for maximum forage production, tall fescue was planted in the fall of 2005. The paddocks were in the establishment phase during 2006. In 2006, after the grass was growing well, soil cores measuring 38.1 cm in diameter and 111.8 cm in length were extracted using PVC pipe and a hollow-core drill. The soil cores were utilized to make zero-tension lysimeters which were then placed back in the ground. The top 40 cm of the PVC pipe was removed to allow for as much unrestricted plant growth as possible. Leachate is collected bi-weekly and analyzed for nitrate nitrogen. Data collection began in June 2007. Beginning in 2008, ammonia emission measurements were collected after each grazing event using dynamic chambers. We are expanding our research focused on implementing advanced wastewater treatment techniques on dairy farms to generate designer manures targeted to better meet crop nutrient needs. Approaches used include enhanced biological P removal (EBPR), struvite crystallization, and deammonification (nitritation coupled with denitrification), in combination with physical and chemical nutrient removal systems. We are achieving significant ammonia removal in our deammonification reactors, and significant P removal in our EBPR reactors. We evaluated combinations of polymers with aluminum sulfate, alumninum chloride, ferric chloride or ferric sulfate for their effectiveness in removing P from dairy manure. We achieved greater than 90% P removal in research scale reactors, and 80% removal of P in a full scale test with a combination of aluminum chloride and a high molecular weight polymer. We have published the results of our work with chemical treatment of manure, and have papers reporting on EBPR and deammonification in review. We have completed and published work evaluating the relative risk of P losses from fescue pasture following application of manures (dairy slurry, swine slurry, beef solids, and poultry litter) or commercial fertilizer. We found that cropland-derived coefficients in the Virginia P Index are generally appropriate for pasture in soils typical of the Shenandoah Valley, but reduction in their magnitude and a differentiation between liquid and solid manures may be warranted. In more complex process-based models, inclusion of season and rainfall duration may be appropriate, to reflect the greater runoff risk during longer rain events and from wet fields early after manure application. Objective 2, Section 2 b. Information. An NRCS CIG grant was awarded to a team of land grant universities and lead by WSU to develop the infrastructure to implement the Feed Management 592 practice standard for NRCS. Tools in the form of assessment tools, checklists, and a feed management template were developed for the species of beef, dairy, swine, and poultry. Training workshops have been held for both nutritionists and technical service providers (nutrient management planners). Objective 3, Refine, evaluate, and apply integrated quantitative models of dairy and beef farms to predict profitability and nutrient losses to the environment. Ammonia Emissions Model: Ammonia emissions from animal feeding operations are an important concern due to their potential adverse effects on animal and human health and the environment. Emissions occur from manure surfaces on the barn floor, during storage, and following field application. Based upon theoretical principles and associated published information on ammonia emission, relationships were refined for modeling the dissociation constant, Henrys law constant and mass transfer coefficient to better predict ammonia loss from manure surfaces. Theoretical inconsistencies in widely used expressions for the dissociation constant and mass transfer coefficient were observed. Refined expressions were developed that relate these parameters to the temperature, pH, and ionic strength of the ammonium containing material, and the velocity of air flowing over the material. These expressions were tested by comparing predicted ammonia emission rates against values measured in controlled laboratory experiments for buffered ammonium-water solutions and dairy cattle manure. Experimental results compared well to values predicted using these theoretical expressions derived from ammonia volatilization literature. These process-level relationships provide a basis for developing predictive tools that quantify management effects on ammonia emissions from farms and thus assist in the development and evaluation of strategies for reducing emissions. Greenhouse Gas Emissions Model: Concern over greenhouse gas emissions and their potential impact on global climate has grown rapidly in the US over the past couple years. Livestock agriculture is recognized as an important emitter of these gases, but little quantitative data exist on emission rate and the effect of management on these emissions. Simple process-level relationships were integrated in the development of a comprehensive model for predicting all important sinks and emission sources to determine a whole-farm carbon balance and an estimate of the net farm emission of greenhouse gas. Relationships were used to track carbon dioxide, methane, and nitrous oxide flows during crop production, from the animals and from manure on the barn floor, during storage and following land application. These relationships were added to the Integrated Farm system Model to predict net greenhouse gas emissions along with nitrogen and phosphorus losses and the overall performance and economics of farm production systems. Dairy Greenhouse Gas Model: The Dairy Greenhouse Gas Model (DairyGHG) was developed to provide an easy to use software tool that estimates total net greenhouse gas emissions and the carbon footprint of a dairy production system. DairyGHG uses a relatively simple process-based model to predict the primary GHG emissions from the production system, which include the net emission of carbon dioxide plus all emissions of methane and nitrous oxide. Emissions are predicted through a daily simulation of feed use and manure handling where daily values of each gas are summed to obtain annual values. A carbon footprint is then calculated as the sum of both primary and secondary emissions in CO2 equivalent units divided by the milk produced. Secondary emissions are those occurring during the production of resources used including machinery, fuel, electricity, fertilizer, pesticides, and plastic. DairyGHG is available for download from our Internet site (http://ars.usda.gov/naa/pswmru). The model includes a fully integrated help system with a reference manual that documents the relationships used to predict emissions.

Arogo Ogejo, J., K. Gungor, Z. Wen, Z. Hu, T. Yao, N. G. Love, and K. F. Knowlton. 2007. Recovery of phosphorus from dairy manure as struvite. Virginia Techs Deans Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation. Beck, J. L., K. Gilmore, N. G. Love, K. F. Knowlton, and J. A. Ogejo. 2007. Nitrogen removal from dairy waste using deammonification fueled by fermented dairy manure. Water Environment Federation Technical Exhibit and Conference (WEFTEC). October 13-17. San Diego, CA. Beck, J. L., N. G. Love, K. F. Knowlton, and J. A. Ogejo. 2007. Nitrogen removal from dairy waste using deammonification fueled by fermented dairy manure. ASABE AIM Tech Session SE-24, Mini-Symposium: Ag Waste Management and Land Application of Waste to Address Environmental Concerns. June 17-20. Minneapolis, MN. Beck, J., K. R. Gilmore, K. F. Knowlton, J. Arogo Ogejo, and N. G. Love. 2007. Nitrogen removal from dairy waste using deammonification fueled by fermented dairy manure. Virginia Techs Deans Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation. Bendfeldt, E., K. F. Knowlton, T. Denckla Cobb, F. Dukes, K. Holm, and J. Arogo-Ogejo. 2008. The Waste Solutions Forum: An innovative and cooperative approach to support the agricultural community and protect water quality. Comm. Dev. 38: 85-93. Chaoui, H., F. Montes, C.A. Rotz and T.L. Richard. 2008. Dissociation and mass transfer coefficients for ammonia volatilization models. ASABE Paper No. 083802, St. Joseph, MI: ASABE. Chen, S., Harrison, J.H., & Zhang, T. (2008). Nutrient Extraction from Liquid Dairy Manure as a Co-product. Conservation Innovation Grant Showcase Soil and Water Conservation Society Meeting, Tucson, AZ. Chianese, D.S., C.A. Rotz and T.L. Richard. 2008. Simulating methane emissions from dairy farms. ASABE Paper No. 084098, St. Joseph, MI: ASABE. Cox, B. G., R. E. James, K. F. Knowlton, M. L. McGilliard, and C. C. Stallings. 2007. Producer perceptions of feed management software. J. Dairy Sci. 90(Suppl. 1):64. Cox, B. G., R. E. James, K. F. Knowlton, M. L. McGilliard, and C. C. Stallings. 2007. Impact of feed management software on whole farm nutrient balance and feeding management. J. Dairy Sci. 90(Suppl. 1):123. 1st place presentation in Southern Regional ADSA Production Division graduate student competition. Daniels, K. M., S. R. Hill, K. F. Kno: wlton, R. E. James, M. L. McGilliard, and R. M. Akers. 2008. Effects of milk replacer composition on selected blood metabolites and hormones in pre-weaned Holstein heifers J. Dairy Sci. 91: 2628-2640. Daniels, K. M., S. R. Hill, K. F. Knowlton, R. E. James, R. E. Pearson, M. L. McGilliard and R. M. Akers. 2007. Effects of milk replacer composition on selected blood metabolites and hormones in pre-weaned Holstein heifers. J. Dairy Sci. 90(Suppl. 1):84-85. Davidson, D., & Harrison, J.H. (2008). Cooling of Dairy Plate Cooler Water Prior to Entry Into Surface Water  Two Case Studies. Proceedings of CSREES Water Quality Annual Meeting CSREES, Reno, NV. DeBusk, J. A., J. A. Ogejo, K. F. Knowlton, and N. G. Love. 2008. Effect of aeration time on nitrification in separated liquid dairy manure. Biosystems Eng. (in review). DeBusk, J. A., J. Arogo, K. F. Knowlton, and N. G. Love. 2008. Chemical phosphorus removal for separated flushed dairy manure. Appl. Eng. in Agric. 24: 499-506. DeBusk, J., J. Arogo Ogejo, N. G. Love, and K. F. Knowlton. 2007. Adjusting N:P ratios in liquid dairy manure through nitrification and chemical phosphorus removal to match crop fertilizer requirements. Virginia Techs Deans Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation. DeBusk, J., J. Arogo, N. Love, and K.F. Knowlton. 2007. Adjusting N:P ratios in liquid dairy manure through nitrification and chemical phosphorus removal to match crop fertilizer requirements. ASABE AIM Tech Session SE-24, Mini-Symposium: Agricultural Waste Management and Land Application of Waste to Address Environmental Concerns. June 17-20. Minneapolis, MN. Dou, Z., C. F. Ramberg Jr., L. Chapius-Lardy, J. D. Toth, Y. Wang, R. J. Munson, Z. Wu, L. E. Chase, R. A. Kohn, K. F. Knowlton, and J. D. Ferguson. 2007. A novel test for measuring and managing potential phosphorus loss from dairy cattle feces. Environ. Sci. Technol. 41: 4361-4366. Dou, Z., C.F. Ramberg, L. Chapuis-Lardy, J. Fiorini, J.D. Toth, J.D. Ferguson. A novel approach for measuring and managing potential phosphorus loss from dairy cattle feces. Environ. Sci. Technol. 41:4361-4366. 2007. Dou, Z., C.R. Chen, C.F. Ramberg, J.D. Toth, Y. Wang, A.N. Sharpley, S.E. Boyd, D. Williams, and Z.H. Hu. Phosphorus speciation and sorption-desorption characteristics in heavily manured soils. Soil Sci. Soc. Am. J. 2008. (in press). García, A.M., T.L. Veith, P.J.A. Kleinman, C.A. Rotz, and L.S. Saporito. Assessing manure management strategies through small-plot research and whole-farm modeling. J. Soil Water Conserv. 63(4): 204-211. 2008. Gay, S. W., J.A. Sparks, L.C. Marr, J. Arogo, M.D. Hanigan, and K.F. Knowlton. 2007. Evaluating the Effect on Dietary Crude Protein Content on Ammonia Flux from Dairy Manure. ASABE AIM Tech Session SE-24, Mini-Symposium: Agricultural Waste Management and Land Application of Waste to Address Environmental Concerns. June 17-20. Minneapolis, MN. Goeser, J. P., L. M. Bauman, P. C. Hoffman, and D.K. Combs. 2008. Comparison of means and run to run variation of in vitro NDFD between two labs using different in vitro NDFD methods. J. Dairy Sci. 91:Suppl 1. P. 35 (ABSTRACT) Goeser, J. P., P. C. Hoffman, and D. K. Combs. 2008. An alternative method to assess 24h ruminal in vitro neutral detergent fiber digestibility. J. Dairy Sci. 91:Suppl 1. P. 35 (ABSTRACT) Goeser, J. P., P. C. Hoffman, and D. K. Combs. 2008. Improvement of the rumen fluid priming method for measuring in vitro NDF digestibility. J. Dairy Sci. 91:Suppl 1. P. 35 (ABSTRACT) Goeser, J. P., P. C. Hoffman, and D. K. Combs. 2008. Amount of sample NDF affects estimates of in vitro NDF digestibility. J. Dairy Sci. 91:Suppl 1. P. 35 (ABSTRACT) Gourley, C.J.P and Powell, J.M. 2007. Nutrient Management Approaches and Tools for Dairy Farms in Australia and the USA. Babcock Technical Bulletin 2007-04. Available: http://babcock.cals.wisc.edu/publications/display.lasso?locale=en&ID=648&Action= The Babcock Institute for International Dairy Research and Development, University of Wisconsin-Madison, 53706 Güngör, K., J. Arogo-Ogejo, K. F. Knowlton, and N.G. Love. 2008. Prefermentation performance of a continuous pilot-scale fermenter treating dairy manure for enhanced biological phosphorus removal. Bioresource Technol. (in review) Gungor; K., J. Arogo Ogejo, K. F. Knowlton, and N. G Love. 2007. Biological phosphorus removal to produce Designer Manures for dairy farms. Virginia Techs Deans Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation. Harrison, J.H. (2008). (Poster) The Role of Feed Management in Whole Farm Nutrient Management. National SARE Conference, KS City. Harrison, J.H., & Bowers, K. (2008). (Poster) Capture of Phosphorus from Liquid Dairy Manure as a Fertilizer for Off-farm Transport. Conservation Innovation Grant Showcase Soil and Water Conservation Society Meeting, Tucson, AZ. Harrison, J.H., White, R., Erickson, G., Sutton, A., Applegate, T., Burns, R., Carpenter, G., Koeslch, R., & Massey, R. (2008). National Feed Management Education and Assessment Tools as part of a Comprehensive Nutrient Management Plan. Conservation Innovation Grant Showcase 2008 Soil and Water Conservation Society Meetings, Tucson, AZ. Harrison, J.H., White, R., Erickson, G., Sutton, A., Applegate, T., Burns, R., Carpenter, G., Koeslch, R., & Massey, R. (2008). National Feed Management Education and Assessment Tools as part of a Comprehensive Nutrient Management Plan. Conservation Innovation Grant Showcase 2008, Soil and Water Conservation Society Meeting, Tucson, AZ. He, Z., H. Zhang, G.S. Toor, Z. Dou, C.W. Honeycutt, and B.E. Haggard. Phosphorus forms in sequentially-extracted fractions of biosolids and broiler litter. Soil Sci. Soc. Am. J. (Submitted). Hill, S. R., K. F. Knowlton, E. Kebreab, J. France and M. D. Hanigan. 2008. A model of phosphorus digestion and metabolism in the lactating dairy cow. J. Dairy Sci. 91: 2021-2032. Hill, S. R., K. F. Knowlton, K. M. Daniels, R. E. James, R. E. Pearson, A. V. Capuco,, and R. M. Akers. 2008. Effects of milk replacer composition on growth, nutrient excretion, and body composition in pre-weaned Holstein heifers J. Dairy Sci. 91: 3145-3155. Hill, S. R., K. F. Knowlton, R. E. James, R. E. Pearson, G. L. Bethard, and K. J. Pence. 2007. Nitrogen and phosphorus retention and excretion in late gestation dairy heifers. J. Dairy Sci. 90: 4356-4360 Hill, S. R., K. M. Daniels, K. F. Knowlton, R. E. James, R. E. Pearson, M. L. McGilliard and R. M. Akers. 2007. The effect of milk replacer composition on growth and body composition of Holstein heifer calves. J. Dairy Sci. 90(Suppl. 1): 297. Hill, S.R., K. F. Knowlton, E. Kebreab, J. France and M. D. Hanigan. 2007. A model of phosphorus digestion and metabolism in the lactating dairy cow. Can. J. Anim. Sci Hollmann, M., K. F. Knowlton, and M. D. Hanigan. 2007. Daily manure nutrient flow from a lactating cow facility. Proc. Tri-State Nutrition Conf. page 121, Ft. Wayne, IN. Hollmann, M., K. F. Knowlton, and M. D. Hanigan. 2008. Evaluation of solids, nitrogen and phosphorus excretion models in lactating dairy cows. J. Dairy Sci. 91:1245-1257. Hollmann, M., K. F. Knowlton, M. L. McGilliard, and G. L. Mullins. 2008. Nutrient runoff potential from fescue pastures using simulated rotational grazing of lactating dairy cows. Comm. Soil Sci. and Plant Anal. 39:2648-2662. Hollmann, M., K. F. Knowlton, M. R. Brosius, M. L. McGilliard, and G. L. Mullins. 2008. Phosphorus runoff potential of varying sources of manure applied to fescue pastures in Virginia. Soil Science 173: 721-735. Jensen, J. 2008. Effects of traditional grazing and deferred grazing on nutrient cycling. MS Thesis. Logan, UT: Utah State University. Jensen, J., and R. L. Miller. 2008. Effects of traditional grazing and deferred grazing on nutrient cycling. In 2008 Agronomy Abstracts. Madison, WI: American Society of Agronomy. Kammes, K. L, G. Heemink, K. A. Albrecht, D. K. Combs. 2008. Utilization of Kura Clover-Reed Canarygrass Silage versus Alfalfa Silage by Lactating Dairy Cows. J. Dairy Sci. 91:3138-3144. Kendall, C., C. Leonardi, P.C. Hoffman and D. K. Combs. 2008. Intake and milk production of cows fed diets that differed in dietary NDF and NDF digestibility. J. Dairy Sci. 91:Accepted in press. Knowlton, K. F., M. S. Taylor, S. R. Hill, C. Cobb and K. F. Wilson. 2007. Manure nutrient excretion by lactating cows fed exogenous phytase and cellulose. J. Dairy Sci. 90: 4356-4360. Kozarek, J. L., M. L. Wolfe, N. G. Love, and K. F. Knowlton. 2008. Sorption of estrogen to three agricultural soils from Virginia. Trans. of the ASABE 51:1591-1597. Kristula, M.A., Z. Dou, J.D. Toth, B. Smith, N. Harvey, and M. Sabo. Evaluation of free stall mattress bedding treatments to reduce mastitis bacterial growth. J. Dairy Sci. 91:1885-1892, 2008. Lopes, J. C., A. P. Vilela, K. A. Weigel, K. A. Albrecht and D. K. Combs. 2008. Production of Holstein and Jersey x Holstein cattle grazing ryegrass/white clover pasture. J. Dairy Sci. 91:Suppl 1. P. 35 (ABSTRACT) M. S. Taylor, K. F. Knowlton, M. L. McGilliard, and J. H. Herbein. 2008. Blood mineral, hormone, and osteocalcin responses of multiparous Jersey cows to an oral dose of 25-Hydroxyvitamin D3 prior to parturition. J. Dairy Sci. 91: 2408-2416. McDowell, R., Z. Dou, J.D. Toth, B. Cade-Menun, P. Kleiman, K. Soder, L. Saporito. Extractability and speciation of phosphorus in feeds and feces of different dairy herds. J. Environ. Qual. 37:741-752, 2008. Miller, R. L, and D. N. Mortensen. 2007. Nutrient leaching and soil compaction in irrigated pastures under management intensive grazing. In 2007 Agronomy Abstracts. Madison, WI: American Society of Agronomy. Miller, R. L. 2008. A Surprising Cause of Air Pollution. Utah Debate Conference. January 26, 2008. Montes, F., C.A. Rotz and H. Chaoui. 2008. Process Modeling of Ammonia Volatilization from Ammonium Solution and Manure Surfaces. ASABE Paper No. 083584, St. Joseph, MI: ASABE. Moreira, V. R., B. D. LeBlanc, E. C. Achberger, D. G. Frederick, C. Leonardi. 2008. Design and Evaluation of a Sequential Biological Treatment System for Dairy Parlor Wastewater in Southeastern Louisiana. Applied Engineering in Agriculture. Submitted. Moreira, V. R., K. J. Han, M. E. McCormick. 2008. Corn silage management for lactating cows. LSU AgCenter, 5 p. 7/23/2008. http://www.lsuagcenter.com/en/crops_livestock/livestock/dairy/ nutrition/Corn+Silage+Management+for+Lactating+Dairy+Cows.htm Mullarky, I. K., W. A. Wark, M. Dickenson, S. Martin, C. S. Petersson-Wolfe, and K. F. Knowlton. 2008. Analysis of immune function in lactating dairy cows on varying phosphorus diets. J. Dairy Sci. (in press) Rotz, C.A. and D.S. Chianese. 2008. The Dairy Greenhouse Gas Model: Reference Manual, version 1.0. Available at: http://www.ars.usda.gov/sp2UserFiles/Place/19020000/DairyGHG ReferenceManual.pdf. Rotz, C.A., H.D. Karsten and R.D. Weaver. 2008. Grass-based dairy production provides a viable option for producing organic milk in Pennsylvania. Online. Forage and Grazinglands doi:10.1094/FG-2008-0212-01-RS. Skinner, R.H., M.S. Corson, and C.A. Rotz. Comparison of two pasture growth models of differing complexity. Agric. Systems (in press, accepted September 22, 2008). Taylor, M. S., K. F. Knowlton, M. L. McGilliard and J. H. Herbein. 2007. Blood mineral, hormone, and osteocalcin responses of multiparous Jersey cows to an oral dose of 25-hydroxyvitamin D3 prior to parturition. J. Dairy Sci. 90(Suppl. 1): 359. Taylor, M. S., K. F. Knowlton, M. L. McGilliard, W. S. Swecker Jr., J. D. Ferguson, and Z. Wu. 2007. Calcium and phosphorus balance and bone mobilization through lactation with varying dietary calcium. J. Dairy Sci. 90(Suppl. 1): 212.1st place presentation in National ADSA Production Division graduate student competition. Taylor, M. S., K. F. Knowlton, M. L. McGilliard, W. S. Swecker, J. D. Ferguson, Z. Wu and M. D. Hanigan. 2008. Dietary calcium has little effect on mineral balance and bone mineral metabolism through 20 weeks of lactation in Holstein cows. J. Dairy Sci. (in press) Velayudhan, B. T., K. M. Daniels, M. L. McGilliard, B. Corl, K. F. Knowlton and R. M. Akers. 2007. Abundance of mRNA expression and nutritional regulation of somatotropic axis genes in the small intestine of prepubertal dairy heifers fed high-protein high-fat milk replaces. J. Dairy Sci. 90(Suppl. 1): 295. White, R., Harrison, J.H., Kincaid, R.L., Block, E., & St Pierre, N. (2008). Effectiveness of potassium bicarbonate to increase dietary cation-anion balance in early lactation cows. Journal of Dairy Science. 91: (E-Supplement 1) 141. White, R., Harrison, J.H., Mertens, D., Yoon, I., Sanchez, B., & Nicholson, N. (in press). Effect of yeast culture on efficiency of nutrient utilization for. The Professional Animal Scientist. 24:114-119. Zhao, Z., K. F. Knowlton N. G. Love, and J. A. Ogejo. 2008. Contribution of 17-² estradiol to total estrogenicity in dairy manure subject to anaerobic digestion or separation and aeration. ASABE Annual International Meeting, Providence, Rhode Island. Paper #084384. Zhao, Z., K. F. Knowlton N. G. Love, and J. A. Ogejo. 2008. Estrogen removal with innovative treatment of dairy manure. ASABE Annual International Meeting, Providence, Rhode Island. Paper # 084366. Zhao, Z., K. F. Knowlton, N. G. Love, and Y. Fang. 2007. Advanced Treatment to Reduce the Estrogen Content of Dairy Manure. World Environmental and Water Resources Congress. May 15-19. Tampa, Florida. Zhao, Z., Y. Fang, N. G. Love, and K. F. Knowlton. 2008. Detection of endocrine disrupting compounds in various manure matrices using bioassays. doi:10.1016/j.chemosphere.2008.09.055