Brief Summary of Minutes of Annual Meeting

Objective 1: Develop selection tools to enhance reproduction and survival using field data.

Georgia investigated the use of different bounds on the genetic parameters of days open in selected states. Subsets of the data were created by truncating DO at 150 to 365 d. The residual variance increased with higher truncation points similarly for all states from about 700 at DO 150 to over 4000 for DO 365. Additive genetic variances generally increased as well, although the pattern of changes was state dependent. Genetic parameters of DO are strongly influenced by editing criteria and by regional differences.

Illinois obtained genetic estimates on calf survival. Twenty bulls were identified as having a bimodal pattern of inheritance using the density estimation procedure PROC KDE in SAS. Thirty two bulls had a normal distribution. Sons of one bull with the bimodal pattern can be divided into two groups for high and low %PTA. The low group had a negative mean, which meant an increased incidence of calf mortality.

Illinois also investigated the probable outcomes of different breeding strategies on the Seeing Eye population of German shepherd dogs and Labrador retrievers, including selection indices, independent trait selection, directional selection, stabilizing selection, and negative assortative mating. Weighting mature weight and mature height equally but in the opposite direction without restrictions was the only index that produced the desired effects of decreasing mature weight and increasing mature height in Labrador retrievers.

Iowa searched for Quantitative Trait Loci (QTL) associated with perinatal survival (PS). Dystocia, age of dam, sex of calf, season and year of birth are frequently associated in varying degrees with low PS. Collaboration with the University of Illinois resulted in the development of a process to characterize the distribution of PTA-PS among sons within paternal half-sib groups. This process identified seventeen families with a bimodal distribution for PTA-PS, i.e., there were two groups of sons within each family, one with a high mean PTA-PS and another with a lower mean PTA-PS. An association was found between PTA-PS in sons of one sire and each of the two alleles for a common marker inherited from that sire.

Nebraska is conducting research on estimating the effect on production for cows given and not given BST. The lactation curves will be based on fitting lactation curves with cubic spline functions. These models can be used to account for standard lactation curve for each cow. This could be useful for lactations longer than 305 days, different types of recording schemes, and records currently in the process of being collected.

New York looked at the effect of diseases on days open, days to first breeding and days from first breeding to conception using survival analysis models, and to assess the significance of the sire component and its possible confounding effect. Ten disease groups were considered as possible risk factors for the reproductive traits. Although the additive genetic components were significant for all traits considered, the sires did not act as confounders.

North Carolina has examined relationships of overall estimated relative conception rates (ERCR) of service sires with 70-day non-return (NR) rates in herds of single states or sets of states within a region. There do not seem to be regional biases in relative relationships of ERCR to 70-day NR rates. Also, effects of inbreeding on reproduction in primiparous Jersey cows were examined. Reduction in fertility, as observed in Jerseys in recent years, is at least partially associated to inbreeding.

Wisconsin looked at the effect of synchronization of estrus or ovulation on genetic parameters of days to first breeding. Individual cow service periods were classified by type of breeding: Standing heat (SH) or any type of synchronization (SYN) protocol applied within 12 days before first insemination. Interval to first breeding, average 72 days, was similar for both treatment groups. Heritability estimates did not differ between SH and SYN treatments. As expected, residual variances were substantially reduced in the SYN treatment group.

Wisconsin also undertook threshold model analysis of male fertility. As expected, mean Veterinary Confirmed Conception Rate (VCCR) was lowest (25.9%) in July and highest (34.1%) in February. Young sires tended to have lower VCCR (27.6%) than proven sires (30.5%), although this is probably a reflection of careless usage of inexpensive young sire semen (e.g., on cows that might not really be in heat) rather than a true indication of biological differences between bulls of different ages. Primiparous cows with daily milk yields > 36 kg/d and multiparous cows with daily yields > 45 kg/d tended to have slightly lower VCCR, by 1.8% and 1.6%, respectively, as compared with other animals of the same age.

Another project in Wisconsin was failure time analysis of health and management influences on female fertility. Cows that were synchronized prior to 75 DIM, 37.9% of the total, were 4% more likely to become pregnant than unsynchronized cows. Cows that had metritis and retained placentas were 20% and 18% less likely, respectively, to become pregnant than cows that had not experienced these disorders.

Tennessee determined heritabilities for electrical conductivity. A repeatability model and five random regression models with increasing order of Legendre polynomials were used. The best model was a model with a 4th order Legendre polynomial for both additive genetic and permanent environmental effects. For this model, heritability estimates ranged from about 0.36 in the beginning and at the end of the lactation to about 0.26 in mid lactation.

Tennessee also estimated genetic correlations between body condition scores (BCS) and dairy form in the US with cow diseases in Denmark. Higher BCS was significantly correlated with less metabolic and digestive disease in first and third lactations. Dairy form was significantly correlated with less metabolic and digestive disease in first lactation and foot and leg disease in first, second and third lactations.

USDA/AIPL refined the evaluation of daughter pregnancy rate. Pregnancy verification codes were added to the AIPL database in 2002, and these veterinary diagnoses are used in calculating DPR instead of assuming that the final insemination was successful. Methods were developed to use records in progress (RIP) for DPR at 130 days in milk (DIM) instead of waiting until 250 DIM for completed records. A new reproductive event (format 5) database is under construction that will allow more detailed analysis of cow fertility and a national evaluation of bull fertility.

USDA/AIPL included service sire calving ease (SCE) and daughter calving ease (DCE) evaluations from USA in pilot studies on international evaluation conducted by Germany and by Interbull. Average genetic correlations of USA with the other 9 countries were .86 for SCE and .64 for DCE. Pilot studies on longevity conducted by Netherlands and Interbull included 3 new countries (United Kingdom, Ireland, and Australia) for a total of 14. USA had the highest average genetic correlation (.74) with the other countries and highest individual correlation (.93) with Canada.


Objective 2: Explore the impact of crossbreeding on lifetime performance of cows.

In Kentucky, matings for the Holstein-Jersey diallel trial began in January, 2003. Mating assignments are made to minimize inbreeding and equalize the representation of service sires. To date seventeen Holstein and twelve Jersey females are confirmed pregnant with calvings beginning in early December.

In Minnesota, Holstein cows in the St. Paul and Morris dairy herds were mated 50% to Holstein sires and 50% to Jersey sires for two years (2000/01 and 2001/02). Beginning December 15, 2002, these project heifers were mated to Holstein sires or Montbeliarde sires. For calving-related traits, Jersey x Holstein crossbred calves were born with significantly less dystocia than pure Holstein calves.

USDA/AIPL developed programs to routinely trace breed composition and calculate heterosis coefficients for all cows and bulls in the AIPL pedigree file.

In Virginia, initial matings to create four breed groups, HH, HJ, JH, and JJ, were begun in August 2002, with first calves born in June 2003. To date, about 40 calves have been born, and additional 90 cows/heifers are pregnant for the project and approximately 100 more are in the process of being bred.

Virginia looked at breed differences in resistance to heat stress. Herds were identified that included both Holstein and Jersey or Holstein and Brown Swiss cows. We examined two traits, age at first calving, and first calving interval.

At Wisconsin, matings of Holstein cows with Jersey x Holstein crossbred bulls in AI was started in February 2002. Detailed health and performance records will be kept on these animals from birth to disposal. Blood samples for DNA analysis will be collected at birth. The genotypes of the backcross animals will be determined at 175 marked locations that span the genome. Relationships between the genotypes and performance traits will be determined.


Objective 3: Develop breeding goals and appropriate indexes for optimum improvement of health, survival, reproduction, and production.

Indiana looked at divergent selection lines for dairy form. Recent studies have demonstrated that daughters of bulls that transmit lower dairy form produce healthier daughters that survive longer, are more fertile, and produce a greater economic return, despite somewhat lower milk yield. Herritability of dairy form is around .30 compared to .04 for fertility, indicating that selection progress for improved fertility may be more quickly attained by indirect selection on dairy form.

In Minnesota, the selection project at the Southern Research and Outreach Center (Waseca), which continued since 1964, was discontinued in 2003. Plans are to maintain the control line into the future with approximately 30 lactating cows, which has been the size of the lactating herd during the years it was housed at Waseca. The change of location for the control line provides new opportunities for research.

Nebraska evaluated autoregressive repeatability animal model for the analysis of first lactation test day records of Holstein cows.

New York looked at the effects of year and season of calving, age at first calving, early milk production, and fraction of North American Holstein genes on days open in primiparous cows were assessed by survival analysis and a sire model. Days open were shorter for cows calving in winter and summer relative to cows calving in autumn. Age at first calving showed an intermediate optimum with a lower hazard of conception for cows calving at an age younger than 23 or older than 27 months relative to cows with age at first calving between 23 and 27 months.

USDA/AIPL revised Net Merit with new economic values estimated with the help of many other researchers in S-1008 and introduced in August 2003. Inclusion of DPR with 7% of total emphasis and calving ease with 4% of total emphasis required relatively less emphasis for some other traits, primarily milk volume, protein, and productive life.


WORK PLANNED FOR NEXT YEAR

Work will continue on analyses of reproductive, production and type traits using different models, including longitudinal and survival. Work will include identification of major gene(s) for selected fitness trait. Matings and data collection for the crossbreeding project will continue

Baumgard, L. H., W. J. Weber, G. W. Kazmer, S. A. Zinn, L. B. Hansen, H. Chester-Jones, and B. A. Crooker. 2002. Effects of selection for milk yield on growth hormone response to growth hormone releasing factor in growing Holstein calves. J. Dairy Sci. 85: 2529-2540.

Berger, P. J., J. Koltes, M. H. Healey, M. S. Ashwell, R. D. Shanks, H. Schlesser, and H. A. Lewin. 2003. Putative quantitative trait loci affecting perinatal survival in eleven Holstein families. J. Dairy Sci. 86(Suppl. 1) : 161.

Blake, R. W. 2002. Differential genetic expression with alternative environmental definitions. Pages 477-489 in Proc. XII Cong. Portuguese Anim. Sci. Assoc. (APEZ), Vila Real, Portugal.

Blake, R. W., and C. F. Nicholson. 2003. Livestock, land use change, and environmental outcomes in the developing world. Invited paper. International conference, Responding to the Increasing Global Demand for Animal Products. Sponsored by British Soc. Anim. Sci., Amer. Soc. Anim. Sci. and Mex. Soc. Anim. Prod., Merida, Mexico.

Blake, R., E. Fereres, T. Henzell, and W. Powell. 2002. Las ciencias agropecuarias en la Argentina (The agricultural sciences in Argentina). Ciencia Hoy (Science Today) 12(70): 31-51.

Boettcher, P.J., J. Fatehi, and M.M. Schutz. 2003. Genotype-by-Environment Interactions in Conventional versus pasture-based dairies in Canada. J. Dairy Sci.86:383-406.

Bohmanova, J., I. Misztal, and J. Pribyl. 2003. Differences in growth trajectories in seven beef breeds. J. Anim. Sci. (Suppl.) 81:198.

Caraviello, D. Z., K. A. Weigel, and D. Gianola. 2003. Analysis of the relationship between type traits and functional survival in US Holstein cattle using a Weibull proportional hazards model. J. Dairy Sci. (submitted).

Caraviello, D. Z., K. A. Weigel, and D. Gianola. 2003. Comparison of Weibull proportional hazards models and linear models for predicting the genetic merit of US Jersey sires for longevity. J. Dairy Sci. (submitted).

Caraviello, D. Z., K. A. Weigel, G. Shook, and P. Ruegg. 2003. Measure of the impact of somatic cell count on longevity of Holstein and Jersey cows using survival analysis. J. Dairy Sci. 86 (Suppl. 1):129.

Carvalheira, J., E. J. Pollak, R. L. Quaas, and R. W. Blake. 2002. An autoregressive repeatability animal model for test-day records in multiple lactations. J. Dairy Sci. 85:2040-2045.

Cassady, J. P. , C. H. Brown, B. T. McDaniel, S. P. Washburn, and J. C. Wilk. 2003. Effects of inbreeding on reproduction in first lactation U.S. Jerseys. Presented as a poster abstract at the American Jersey Cattle Association-National All-Jersey annual meetings. Adams-Mark Hotel; Columbus, Ohio. June 25-28.

Cassell, B. G. 2002. Calving ease evaluations are being improved. Hoards Dairyman.147(16):626-627

Cassell, B. G. 2002. Has semen really become a commodity? Hoards Dairyman, 147(12):488.

Cassell, B. G. 2002. Is it time to select for disease resistance? Hoards Dairyman.147(18):716-717.

Cassell, B. G. 2002. She will live a LOT longer if she is pregnant. Hoards Dairyman.147(14):555.

Cassell, B.G. V. Adamec, and R.E. Pearson. 2003. Maternal and fetal inbreeding depression for 70-day non-return and calving rate in Holsteins and Jerseys. J. Dairy Sci. 86:2977-2983. Wisconsin

Cassell, B.G., S.M. Jobst, M.L. McGilliard, and R.E. Pearson. 2002. Evaluating sire selection practices using lifetime net income functions. J. Dairy Sci. 85:3492-3502.

Cassell, B.G., V. Adamec, and R.E. Pearson. 2003. Effect of incomplete pedigrees on estimates of inbreeding and inbreeding depression for days to first service and summit milk yield in Holsteins and Jerseys. J. Dairy Sci. 86:2967-2976.

Cruickshank, J., M. R. Dentine, P. J. Berger, and B. W. Kirkpatrick. 2003. Detecting quantitative trait loci for twinning and production traits in Holstein dairy cattle. J. Dairy Sci. 86(Suppl. 1): 195.

Dechow, C. D., G. W. Rogers, L. Klei, and T. J. Lawlor. 2003. Heritabilities and correlations among body condition score, dairy form, and selected linear type traits. J. Dairy Sci. 86:2236-2242.

Dechow, C. D., G. W. Rogers, T. J. Lawlor, L. Klei, A.E. Freeman, and G. Azim. 2003. Genetic correlations among body condition score, dairy form and disease from the US. J. Dairy Sci. 86(Suppl. 1):196. (Abstr.).

Dechow, C. D., G. W. Rogers, T. J. Lawlor, L. Klei, and P.M. VanRaden. 2003. Genetic correlation estimates among body condition score, dairy form, days open and production traits in US Holsteins. J. Dairy Sci. 86(Suppl. 1):130. (Abstr.).

DeGroot, B.J., J.F. Keown, S.D. Kachman, and L.D. Van Vleck. 2003. Estimates of genetic parameters for first lactation test-day yields of Holstein cows with a cubic spline model. J. Anim. Sci. 81:(Suppl.1)3.

DeGroot, B.J., J.F. Keown, S.D. Kachman, and L.D. Van Vleck. 2003. Use of cubic splines for estimating lactation curves of Holstein cows treated with bovine somatotropin. 15th Ann. Kansas State Univ. Conf. on Applied Statistics in Agriculture.

DeGroot, B.J., J.F. Keown, S.D. Kachman, and L.D. Van Vleck. 2003. Estimates of genetic parameters and lactation curves with a cubic spline model for Holstein cows treated with bovine somatotropin. J. Dairy Sci. 86:(Suppl.1) 37.

Druet, T., J. Svlkner, I. Misztal, and N. Gengler. 2002. On the value of incorporating dominance effects in genetic evaluation of dairy cattle. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 01:44.

Edwards, J.L. and Tozer, P.R. 2003. Using activity and milk yield as predictors of fresh cow disorders. J. Dairy Sci.86(Suppl. 1):55 (abstr. 222).

Gengler, N., G.R. Wiggans, J.R. Wright, and T. Druet. 2002. Simultaneous multitrait estima-tion of genetic merit and heterogeneous variances for type traits. J. Dairy Sci. (submitted)

Goodling, R. C., G. E. Shook, K. A. Weigel, N. R. Zwald, and R. D. Welper. 2003. Effect of synchronization protocols on genetic parameters of reproductive traits in dairy cattle. J. Dairy Sci. 86 (Suppl. 1):129.

Hammell, E. E., M. L. Raeth-Knight, E. Ballinger, J. G. Linn, A. J. Seykora, and L. B. Hansen. 2003. Performance of Holstein and Jersey-Holstein crossbred heifer calves when using an intensive feeding program from birth to 84 days of age. J. Dairy Sci. 81(Suppl. 1):173.

Hansen, L. B. 2002. The role of genetics in cow longevity. Proceedings of the Midwest Dairy Herd Health Conference, Middleton, WI, University of WI-Dairy Extension (November 13).

Heins, B. J., A. J. Seykora, and L. B. Hansen. 2003. Effect of mating Holstein females to Holstein versus Jersey AI sires on fertility, dystocia, calf weight, and retained placenta. J. Dairy Sci. 81(Suppl. 1):130.

Heins, B. J., L. B. Hansen, and A. J. Seykora. 2003. Comparison of Holstein, Jersey-Holstein crossbred, and Normande-Holstein crossbred first-parity cows for milk, fat, and protein production and SCS during the first 150 days of lactation. J. Dairy Sci. 81(Suppl. 1):39.

Helmink, S.K., R. D Shanks, and E.A. Leighton. 2003. Investigation of breeding strategies to increase the probability that German shepherd dog and Labrador retriever dog guides would attain optimum size. J. Animal Sci.(accepted)

Huang, Y-C., and R. D. Shanks. 2002. Genetic aspect of foot abscess, heel warts and interdigital hyperplasia in dairy cattle. J Chin. Soc. Animal Sci. 31(2):141-155.

Johanson, J. M. and P. J. Berger. 2003a. A within herd evaluation of sires for perinatal mortality including birth weights. Midwest Branch ADS 2003 Meeting, Des Moines, IA. Abstr. #2.

Johanson, J. M. and P. J. Berger. 2003b. Birth weight as a predictor of calving ease and perinatal mortality in Holstein cattle. J. Dairy Sci. 86: (in press).

Kassa, H., R. W. Blake, and C. F. Nicholson. 2002. The crop-livestock subsystem and livelihood dynamics in the Harar Highlands of Ethiopia. Pages 74-75 in Proc. Responding to the Increasing Global Demand for Animal Products.

Kearney, J.F., M.M. Schutz, and P.J. Boettcher. 2003. Genotype by environment interaction in grazing versus confinement dairy production. II. Health and reproduction. J. Dairy Sci. (In Press).

Kearney, J.F., M.M. Schutz, P.J. Boettcher, and K.A. Weigel. 2003. Genotype by environment interaction in grazing versus confinement dairy production. I. Milk production traits. J. Dairy Sci.(In Press).

Kolter, J., P.J.Berger, J.C.M. Dekkers, M.H. Healey, M.S. Ashwell, R.D. Shanks, H. Schlesser, and H.A. Lewin. 2003. Evidence for major quantitative trait loci affecting perinatal survival in two elite Holstein sire families. Proc. The John M. Airy Beef Cattle Symposium. Visions for genetics and breeding. p131. Ed. J. M. Reecy.

Koltes, J., P. J. Berger, J. C. M. Dekkers, M. H. Healey, M. S. Ashwell, R. D. Shanks, H. Schlesser, and H. A. Lewin. 2003. Evidence for major quantitative trait loci affecting perinatal survival in two elite Holstein sire families. Proc. The John M. Airy Beef Cattle Symposium. Visions for genetics and breeding. p131. Ed. J. M. Reecy. Johnston, IA.

Kuhn, M. T., P. M. VanRaden, and J. L. Hutchison. Use of early lactation days open records for genetic evaluation of cow fertility. J. Dairy Sci. (submitted)

Kuhn, M.T. and VanRaden, P.M. 2003. Use of early lactation days open records for genetic evaluation of cow fertility. J. Dairy Sci.86(Suppl. 1):132 (abstr. 522).

Lawlor, T. J., S. Tsuruta, L. Klei and I. Misztal. 2002. Use of a random regression model to investigate changes in genetic parameters over time. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 17:06.

Legarra, A., I. Misztal, and J. Jamrozik. 2003. Plotting covariance functions from random regression models. J. Dairy Sci (Suppl. 1) 86: 114.

Legarra, A., T. Strabel, J. K. Bertrand, and I. Misztal. 2003. Setting up the Gelbvieh Multiple Breed Evaluation. J. Anim. Sci. (Suppl.) 81:198.

Luimes, P. H., E. H. Beaupre, J. H. White, W. J. Weber, H. Chester-Jones, L. B. Hansen, B. A. Crooker, and J. R. Knapp. 2003. The effect of phenotypic selection for milk production on hepatic expression of prolactin receptor. J. Dairy Sci. 81(Suppl. 1):118.

Marx, G. D, and L. B. Hansen. 2003. Dairy research on large and small cows changes industry standards. Minnesota Holstein News, March 2003: 26-27.

Meier, B. J., M. Hutjens, H. M. Dann, and R. D. Shanks. 2003. Manure evaluation field study. Illinois Dairy Day Report. p. 24-25.

Miller, R.H., Norman, H.D., Wiggans, G.R., and Wright, J.R. 2003. Test-day milk loss associated with elevated test-day somatic cell score. J. Dairy Sci.86(Suppl. 1):195 (abstr. M65).

Misztal I., and O. Ravagnolo. 2002. Studies on genetics of heat tolerance in Holsteins. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 18:05.

Misztal, I., S. Oseni, and S. Tsuruta. 2003. Analyses of heat tolerance for milk in Holsteins using different sources of heat-stress information. J. Dairy Sci (Suppl. 1) 86: 39.

Misztal, I., S. Tsuruta,T. Strabel, B. Auvray, T. Druet, and D. H. Lee. 2002. BLUPF90 and related programs (BGF90). Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 28:07.

Montaldo, H., J.F. Keown, L.D. Van Vleck, and C.P. Van Tassell. 2003. Economic evaluation of Holstein sires selection strategies for herds in Italy, Mexico, The Netherlands and the United States using stochastic stimulation. Revista Veterinaria Mexico 34(2):179-201. Series # 13429.

Munthala, M. B., A. P. Schinckel, M. M. Schutz, and T. S. Stewart. 2003. Response to selection for growth traits in purebred and crossbred pigs selected on a maternal line index. Midwest Dairy and Animal Science Meetings, Des Moines, IA. JAS (Abstr.)

Nash, D. L., G. W. Rogers, W. M. Sischo, J. B. Cooper, G. L. Hargrove, and J. F. Keown. 2003. Heritability of intramammary infections at first parturition and relationships with sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield. J. Dairy Sci. 86:2648-2242.

Nash, D.L., G.W. Rogers, J.B. Cooper, G.L. Hargrove, and J.F. Keown. 2003. Heritability of intramammal infections at first parturition and relationships with sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield. J. Dairy Sci. 86:2684-2695. J. Series # 13225.

Nobre P. R. C., I. Misztal, S. Tsuruta, J. K. Bertrand, L. O. C. Silva, and P. S. Lopez. 2002. Genetic evaluation of growth in beef cattle with a random regression model. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 20:10.

Nobre, P. R. C. , I. Misztal , S. Tsuruta, J. K. Bertrand, L. O. C. Silva, and P. S. Lopes. 2003. Analyses of Growth Curves of Nelore Cattle by Multiple Trait and Random Regression Models. J Anim. Sci. 81:918-926.

Nobre, P. R. C. , I. Misztal , S. Tsuruta, J. K. Bertrand, L. O. C. Silva, and
P. S. Lopes. 2003. Genetic evaluation of growth in Nellore cattle by multiple trait and random regression models. J Anim. Sci. 81:927-932.

Norman, H.D., Wright, J.R., and Powell, R.L. 2003. Performance of Holsteins that originated from embryo transfer or multiparous births. J. Dairy Sci.86(Suppl. 1):317 (abstr. W89).

Norman, H.D., Wright, J.R., VanRaden, P.M., and Kuhn, M.T. 2003. Characteristics of genetic evaluations for daughter fertility in relation to other fitness traits. J. Dairy Sci.86(Suppl. 1):131 (abstr. 519).

Oseni, S., and I. Misztal. 2002. Seasonality of days open in US Holsteins. J. Dairy Sci (Suppl. 1) 86: 131.

Oseni, S., I. Misztal, S. Tsuruta, and R. Rekaya. 2003. Seasonality of Days Open in US Holsteins. J. Dairy Sci. 86:3718-3725.

Pettersson G.K., P.A. Oltenacu, D.O. Maizon, E.C. Svensson, P.G.A. Liberg. 2002. Effects of dam-related factors on heart girth at birth and morbidity, and of dam, environment, and management-related factors on growth rate from birth to 90 days of age in Swedish dairy calves. Prev. Vet. Med. (Accepted, In press).

Powell, R.L. and P.M. VanRaden. 2003. Correlation of longevity evaluation with other trait evaluations from 14 countries. Interbull Bulletin 30: 15-19. Dept. Anim. Breeding and Genet., SLU, Uppsala, Sweden.
Powell, R.L., Sanders, A.H., and Norman, H.D. 2003. Accuracy of foreign dairy bull evaluations in predicting US evaluations for yield. J. Dairy Sci.86(Suppl. 1):38 (abstr. 153).

Raeth-Knight, M. L., J. G. Linn, D. G. Johnson, L. B. Hansen, A. J. Seykora, B. J. Heins, and R. M Templeton. 2003. Performance of Holstein and Holstein-Jersey crossbred heifer calves from birth to 84 days of age. J. Dairy Sci. 81(Suppl. 1):22.

Raffrenato, E., R. W. Blake, P. A. Oltenacu, J. Carvalheira, and G. Licitra. 2003. Genotype by environment interaction for yield and somatic cell score with alternative environmental definitions. J. Dairy Sci. 86:2470-2479.
Reynoso-Campos, O., D. G. Fox, R. W. Blake, M. C. Barry, L. O. Tedeschi, C. F. Nicholson, H. M. Kaiser, and P. A. Oltenacu. 2003. Predicting nutritional requirements and lactation performance of dual-purpose cows using a dynamic model. Agric. Syst. (in press)

Rogers, G. W. 2003. How dangerous is inbreeding? The Dairy Mail. March. 10:75-76.

Rogers, G. W. 2003. Longevity or Survival. The Dairy Mail. May. 10:83-85.

Rogers, G. W. 2003. Reduced clinical mastitis  breed for lower SCCs. The Dairy Mail. January. 10:85-87.

Rogers, G. W. 2003. Semen quality lowers risk. The Dairy Mail. July. 10:103-105.

Rueda, B., R. W. Blake, C. F. Nicholson, D. G. Fox, L. O. Tedeschi, A. N.

Pell, E. C. M. Fernandes, J. F. Valentim, and J. da Costa. 2003. Production and economic potentials of cattle in pasture-based systems of the western Amazon region of Brazil. J. Anim. Sci. (in press)

Rueda, B., R. W. Blake, E. Fernandes, C. F. Nicholson, and J. F. Valentim. 2003. Soil, plant and cattle nutrient dynamics on pastures of the western Amazon of Brazil. Agric. Ecosys. Environ. (submitted)

Sanders, A.H., Ross, F.A., and Norman, H.D. 2003. Using the internet for distribution of dairy genetic evaluations and research information to the dairy industry. J. Dairy Sci.86(Suppl. 1):162 (abstr. 642).

Sapp, R. L., R. Rekaya, J. K. Bertrand, I. Misztal, and K. A. Donoghue. 2002. Genetic parameter estimates of udder scores in Gelbvieh cattle. J. Anim. Sci. (Suppl.) 81:88.

Schlesser, H., R.D. Shanks, P.J. Berger, M.H. Healey. 2003. Graphical approach to evaluate genetic estimates of calf survival. J. Dairy Sci. 86(Suppl. 1): 196 (Abstr).

Seykora, T. and VanRaden, P.M. 2003. Changes to Net Merit ushered in with August proofs. Hoard‘s Dairyman 148(14):531.
Shanks, R. D. 2003. A new genetic evaluation for fertility. Illinois Dairy Day Report. p. 36-37.

Spike, P. L., R. R. Benson, R. L. Fernando, J. C. M. Dekkers, P. J. Berger, and B. R. Skarr. 2003. A simulation program using finite loci with infinite possibilities. J. Dairy Sci. 86(Suppl. 1): 113.

Tsuruta S., I. Misztal, T. J. Lawlor, and L. Klei. 2002. Estimation of genetic parameters over time for final score in holsteins using a random regression model. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 17:20.

Tsuruta, S., I. Misztal, and T. Druet. 2003. Comparison of estimation methods for heterogeneous residual variances with random regression models. J. Dairy Sci (Suppl. 1) 86: 113.

Tsuruta, S., I. Misztal, T. J. Lawlor, and L. Klei. 2003. Estimation of genetic correlations among production, body size, udder, and productive life traits over time in Holsteins. J. Dairy Sci (Suppl. 1) 86: 38.

Vallejo, R. L., Y. L. Li, G. W. Rogers, and M. S. Ashwell. 2003. Genetic diversity and background linkage disequilibrium in North American Holstein Cattle population. J. Dairy Sci. 86:(currently in typesetting).

Vallimont, J. E., G. W. Rogers, L. A. Holden, M. L. OConnor, J. B. Cooper, C.D. Dechow, and J.S. Clay. 2003. Milk urea nitrogen and conception rate: a population study using test-day records. J. Dairy Sci. 86(Suppl. 1):239. (Abstr.).

Van Tassell, C. P., G. R. Wiggans, and I. Misztal. 2003. Implementation of a sire-maternal grandsire model for evaluation of calving ease in the United States. J. Dairy Sci. 86:3366-3373.

VanRaden, P. M., A. H. Sanders, M. E. Tooker, R. H. Miller, H. D. Norman, M. T. Kuhn, and G. R. Wiggans. Development of a national genetic evaluation for cow fertility. J. Dairy Sci. (submitted)

VanRaden, P.M. 2003. Longevity and fertility trait definitions compared in theory and simulation. Interbull Bulletin 30: 43-46. Dept. Anim. Breeding and Genet., SLU, Uppsala, Sweden.

VanRaden, P.M. and A.J. Seykora. 2003. Net merit as a measure of lifetime profit: 2003 revision. http://aipl.arsusda.gov/reference/nmcalc.htm

VanRaden, P.M. and Tooker, M.E. 2003. Definition of traits and comparison of models for genetic evaluation of cow fertility. J. Dairy Sci.86(Suppl. 1):131 (abstr. 520).

VanRaden, P.M., and A.H. Sanders. 2003. Economic merit of crossbred and purebred US dairy cattle. J. Dairy Sci. 86:1036-1044.

VanRaden, P.M., Tooker, M.E., Sanders, A.H., and Wiggans, G.R. 2003. Quality of data included in genetic evaluations for daughter pregnancy rate. J. Dairy Sci.86(Suppl. 1):132 (abstr. 521).

VanRaden, Paul, Ashley Sanders, Melvin Tooker, Bob Miller, and Duane Norman. 2002. Daughter pregnancy rate evaluation of cow fertility. http://aipl.arsusda.gov/reference/fertility/DPR_rpt.htm

Vasconcelos, J., A. Martins, M. F. Petim-Batista, J. Cola, R. W. Blake, and J. Carvalheira. 2003. Prediction of daily and lactation yields of milk, fat and protein using an auroregressive repeatability test day model. (in preparation)

Washburn, S. P., W. J. Silvia, C. H. Brown, B. T. McDaniel, and A. J. McAllister. 2002. Trends in reproductive performance in Southeastern Holstein and Jersey DHI herds. J. Dairy Sci. 85:244-251.

Weber, W. J., S. J. Kolath, M. C. Lucy, H. Chester-Jones, L. B. Hansen, and B. A. Crooker. 2003. Effect of genetic potential for milk yield on the onset of reproductive activity and corpus luteum function in Holstein cows. J. Dairy Sci. 81(Suppl. 1):238.

Weigel, K. A. 2003. Genetic selection for improved reproduction. J. Dairy Sci. 86 (Suppl. 1):66.

Weigel, K. A., and K. A. Barlass. 2002. Results of a producer survey regarding crossbreeding in US dairy cattle. J. Dairy Sci. (submitted).

Weigel, K. and VanRaden, P.M. 2003. Fertility is now a selection trait. Hoard‘s Dairyman 148(5):180. (Also published as "New evaluations offer a genetic approach to improving cow fertility", NAAB Electronic Resource Guide)

Weigel, K.A. 2003. Improving the reproductive efficiency of dairy cattle through genetic selection. J. Dairy Sci. (accepted).

Wiggans, G. R., C.P. Van Tassell, J.C. Philpot and I. Misztal. 2002. Comparison of dystocia evaluations from sire and sire-maternal grandsire threshold models. Proc. 7th World Congress Gen. Appl. Livest. Prod., Monteplier, France. CD-ROM communication 20:17.

Wiggans, G. R., I. Misztal, and C. P. Van Tassell. 2003. Calving Ease (Co)Variance Components for a Sire-Maternal Grandsire Threshold Model. J. Dairy Sci. 86:1845-1848.

Wiggans, G.R., Misztal, I., and Van Tassell, C.P. 2003. Calving ease (co)variance components for a sire-maternal grandsire evaluation model. J. Dairy Sci. 86(5):1845-1848.

Wilson, R. D., K. A. Weigel, P. M. Fricke, M. L. Leibfried-Rutledge, D. L. Matthews, and V. R. Schutzkus. 2003. Combining in vitro embryo production and sexed semen technologies. J. Dairy Sci. 86 (Suppl. 1):118.

Zwald, N. R., and K. A. Weigel. 2003. Identification of environments for AI progeny testing schemes that yield the highest heritability and correlation with second-crop evaluations for yield and type traits. J. Dairy Sci. 86 (Suppl. 1):38.

Zwald, N. R., K. A. Weigel, and R. Welper. 2003. Analysis of health and fertility traits for proven and young sires in herds participating in a progeny test program using data from on-farm herd management software. J. Dairy Sci. 86 (Suppl. 1):196.