Andrew J. Roberts Adjunct Faculty USDA-ARS 243 Fort Keogh Road University of Idaho Miles City, MT 59301-4016   Phone: 406-874-8216 Fax: 406-874-8289 Email:andy@larrl.ars.usda.gov   Ph.D. Washington State University ­ Animal Sciences, 1988 M.S. University of Wyoming ­ Animal Sciences, 1984 B.S. New Mexico State University ­ Animal Sciences, 1982 RESEARCH INTERESTS: Develop Beef Cattle Better Suited for Sustainable Production.   RESEARCH SUMMARY: 1) Determine the role of follicular growth in maintaining pregnancy during early gestation. 2) Determine genetic and environmental partitioning of phenotypic variation in reproductive traits of heifers and bulls measured early in life under two differing planes of nutrition and evaluate their relationships with lifetime reproductive performance of cows. 3) Identify quantitative trait loci and novel genes affecting attainment of puberty, probability of conception, return to estrus after calving, reproductive longevity, and other components of sustained reproduction. 4) Develop selection methods to increase genetic potential for profitability of beef production through optimal use of feed inputs in sustainable cow-calf production.   REPRESENTATIVE PUBLICATIONS: Funston, R. N., R. J. Lipsey, T. W. Geary, and A. J. Roberts. 2005. Effect of administration of human chorionic gonadotropin after artificial insemination on concentrations of progesterone and conception rates in beef heifers. J. Anim. Sci.83:1403-1405. Roberts, A. J., J. Klindt and T. G. Jenkins. 2005. Effects of varying energy intake and sire breed on duration of postpartum anestrus, insulin-like growth factor -1 and growth hormone in mature crossbred cows. J. Anim. Sci.83:1705-1714. MacNeil, M. D., T. W Geary, G. A. Perry, A. J. Roberts and L. J. Alexander. 2006. Genetic partitioning of variation in ovulatory follicle size and probability of pregnancy in beef cattle. J. Anim. Sci. 84:1646-1650. Roberts, A. J., M. J. Al-Hassan, P. M. Fricke, and S. E. Echternkamp. 2006. Large variation in steroid concentrations and insulin-like growth factor binding proteins exists among individual small antral follicles collected from within cows at random stages of estrous cycle. J. Anim. Sci. 84:2714-2724. Perry, G. A., M. F. Smith, A. J. Roberts, M. D. MacNeil, and T. W. Geary. 2006. Relationship between size of ovulatory follicle and pregnancy success in beef heifers. J. Anim. Sci. 85:684-689