Submitted to: Beef Improvement Federation Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/25/2002
Publication Date: 7/30/2002
Citation: Jenkins, T.G., Ferrell, C.L. 2002. Beef cow efficiency - revisited. Beef Improvement Federation Proceedings. pp. 32-43. Interpretive Summary: Cow/calf producers provide animals targeted for meeting the demand for high quality, nutritious product for the American producer. Approximately 60-70% of the feed required to produce a pound of beef product is consumed by producing females. Cow/calf producers need information to improve efficiency of production. Data presented document differences exist among cattle breeds and breed crosses for traits that directly and indirectly affect the efficiency of production. Experimental evidence for genetic differences in growth, appetite, lactation, fattening ability and maintenance efficiency was reviewed. Results from a five-year study with mature cows were reviewed. Cows representing breeds of cattle with high genetic potential for milk production and growth had lower production efficiency in an environment of lower feed energy availability. At higher feed availability, the reproductive performance of those breeds characterized as having greater potential for growth and lactation was not limited and these types were more effective in converting feed energy to calf weight. When applied at the herd level, a critical finding from this research is that the relationship between herd productivity and feed resources is curvilinear. This suggests that an optimum feeding strategy can be developed to improve cow efficiency.
Technical Abstract: Variation exists among cattle populations to improve the conversion of feed resources to a final product. A biologically efficient cow is one producing a calf each year she remains in the cowherd. The nutrition-reproduction axis may influence this success. Energy expenditure for maintenance may affect the reproduction of the cow. Energy expenditure for maintenance appears to be correlated to genetic potential for mature size and lactation. At restricted feed availability, an increase in maintenance efficiency among breeds with greater potential for size can be associated with longer postpartum periods for mature cows resulting in a lower reproductive rate thus lowering cow efficiency. At lower intakes, variation in milk production exists among breeds with higher milk production potential, resulting in lowered efficiency of gain for calves with higher growth potential.