Brief Summary of Minutes of Annual Meeting

Members Not Attending: Jason Ahola and Cassie Welch, Idaho; Larry Berger, Illinois; Grant Crawford, Minnesota; Gustavo Cruz, California; Robert Dailey and Eugene Felton, West Virginia; Robert Herd, Australia; Travis Maddock, Florida; Robert Myer, Florida; Roberto Sainz, California; Thomas Welsh, Texas; Robert Wettemann, Oklahoma; Scott Whisnant, North Carolina. The annual meeting of the W1010 technical committee was held in Columbia, Missouri on July 1 and 2, 2010. The meeting was called to order by esteemed chair, Professor Gordon Carstens. The group was welcomed to the University of Missouri by Dr Rod Geisert, Director of the Division of Animal Sciences. Each of the stations attending prepared a brief written report and presented this information to the group in attendance. In the business meeting, Dr Bret Hess provided programmatic updates relevant to the technical committee and also provided insight into NIFA funding opportunities. It was decided that the next year meeting would be held immediately after BIF meetings in Montana. Dr Kerley will serve as Chair in 2010-11. Dr Kriese-Anderson was elected to serve as Secretary. Following experiment station presentations, the committee explored avenues, mechanisms and future plans for collaborative research and joint grant submissions. A great time was had by all, the weather was typical for Missouri in July, and all noted the children were above average in Columbia.

Results of research conducted by members of the committee indicate that: - high efficiency heifers tend to carry less body fat and appear to reach puberty approximately seven days later for each one kg improvement of residual feed intake (FRI); - within animal repeatability of feed behavior traits are high and that they may be useful indicator traits for RFI in beef cattle; - RFI was not phenotypically associated with scrotal circumference or semen quality traits in growing bulls; - RFI in bulls and steers is not the same trait, which is probably not unexpected given the physiological differences between steers and bulls. Genetic correlations between bull and steer RFI may need to be taken into consideration when making genetic selection decisions; - thyroid hormone may be involved in the regulation of maintenance energy requirement (MR) of beef cows during late gestation. Identification of cows with lower MR and greater efficiency could improve the profitability of beef production; - selection for serum IGF concentration may affect mature weights in cattle and that heifers selected for high IGF-I concentration may have lighter mature weights and lower maintenance requirements as cows than those selected for low IFG-I concentration; - mitochondrial function explains, at least in part, RFI differences among cattle.

Davis, M.E., and R.C.M. Simmen. 2010. Estimates of inbreeding depression for serum insulin-like growth factor I concentrations, body weights, and body weight gains in Angus beef cattle divergently selected for serum insulin-like growth factor I concentration. J. Anim. Sci. 88:552-561. Smith, S.N., M.E. Davis, and S.C. Loerch. 2010. Residual feed intake of Angus beef cattle divergently selected for feed conversion ratio. Livest. Sci. doi:10.1016/j.livsci.2010.04.019. Qing, Q. 2010. Effect of Divergent Selection for Insulin-Like Growth Factor I (IGF-I) on Mature Weight and Growth Curves in Angus Cattle. M.S. Thesis. The Ohio State University, Columbus. Barioni, L.G., V.A.T. de León, J.W. Oltjen, and R.D. Sainz. 2009. A Hybrid Algorithm to Optimize Beef Feedlot Operations. 7th International Workship Modelling Nutrient Digestion and Utilization in Farm Animals, Paris, September 10-12. p.61 de León, V.A., L.G. Barioni, J.W. Oltjen, and R.D. Sainz. 2009. Development of a heat balance model for cattle. 7th International Workship Modelling Nutrient Digestion and Utilization in Farm Animals, Paris, September 10-12. p.43. McPhee, M., J. Oltjen, J. Fadel, D. Mayer and R. Sainz. 2009. Parameter estimation and sensitivity analysis of fat deposition models in beef steers using acslXtreme. Mathematics and Computers in Simulation 79 :27012712. Oltjen, J.W., A. Ahmadi, A.J. Romera, D.J. Drake, P. Gaspar and S.J.R. Woodward. 2009. PCRANCH: Cow-Calf Herd Simulation System. 7th International Workship Modelling Nutrient Digestion and Utilization in Farm Animals, Paris, September 10-12. p. 64. Prado-Cooper, M., 2009. Maintenance energy requirements, postpartum reproduction, and ruminal temperature at parturition and estrus of beef cows. PhD Dissertation. Oklahoma State University Bailey, C.L., 2009. Identification of maintenance energy requirements and estrus in beef cows. MS Thesis. Oklahoma State University Prado-Cooper, M.J., R.D. Madden, J.W. Dillwith, C.L. Bailey, E.C. Wright, K.R. HR.Krehbiel, D.L. Step, and R.P. Wettemann. 2009. Proteomic analyses in beef cows with low and high maintenance energy requirements. J. Anim. Sci. (E-Suppl. 2)87:296. Pye, T.A., B.H. Boehmer, and R.P. Wettemann. 2010. Maintenance energy requirements of gestating beef cows, rumen temperature, and plasma concentrations of thyroxine and triiodothyronine. J. Anim. Sci. (E-Suppl. 2)88:403. Rutherford, William Cobie Jr. 2010. Thesis: Evaluation of residual feed intake in centrally-tested bulls and related steers. Accessed 8/16/2010. (http://etd.auburn.edu/etd/handle/10415/2038). Rutherford, W.C., L.A. Kriese-Anderson and G.S. Hecht. 2010. Heritability and genetic correlations of residual feed intake between Angus and Simmental bulls and resulting steer relatives. Abstract 69 presented at the American Society of Animal Science Annual Meeting. July 11-15, 2010. Denver, CO. Accessed 8/16/2010 (http://adsa.psa.ampa.csas.asas.org/meetings/2010/abstracts/0184.pdf). 88 (e-supplement 2):184-185. Hafla, A.N., P.A. Lancaster, G.E. Carstens, D.W. Forrest, J.T. Fox, M.E. Davis, R.D. Randel and J.W. Holloway. 2010. Relationships between feed efficiency traits, and scrotal circumference and semen-quality traits in yearling bulls. J. Anim. Sci. (E-Suppl. 3) 88:13. Mendes, E.D.M., G.E. Carstens and L.O. Tedeschi. 2010. Characterization of feeding behavior traits and associations with feed efficiency in beef heifers fed a high-grain diet. J. Anim. Sci. (E-Suppl. 2) 88:791.