Submitted to: Nutrition Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2002
Publication Date: 2/21/2002
Citation: Duff, G.C., Galyean, M.L., Cole, N.A. 2002. Dietary protein for beef cattle finishing diets. In: Proceedings of 17th Annual Southwest Nutrition and Management Conference, February 21-22, 2002, Phoeniz, Arizona. p.143-155.
Technical Abstract: Protein requirements and utilization by ruminants have been extensively evaluated. Protein nutrition is again the focus of research because of the potential impact of nitrogen (N) on the environment. Excess nutrients (N, P, etc.) in manure can pose a threat to soil, water, and air quality. Diet composition can influence the quantity and chemical composition of manure produced, affect the composition of runoff from feedyards or fields fertilized with feedlot manure, and also affect air quality. This paper highlights current research programs evaluating protein concentrations and sources for ruminants during various stages of growth. For newly-received beef calves, it appears that the optimum level of urea to feed with a high-concentrate, processed grain receiving diet is approximately 0.5% of the DM for maximum feed efficiency. The Consortium for Cattle Feeding and Environmental Sciences, a group of university and USDA scientists, are currently conducting research to study the impact of N and P on various aspects of beef cattle feeding operations. One study that evaluated protein concentrations and protein sources for finishing yearling steers suggests that daily gain and daily feed intake can be increased by feeding diets with 13.0% CP compared with 11.5 or 14.5% CP diets; however, no differences in feed efficiency resulted. Results from this and 7 other Consortium projects will be used for development of a national feed database and computer models/decision tools to predict optimum protein nutrition in feedlot cattle.