Effects of Source and Level of Ruminally Protected Choline on Performance and Carcass Characteristics of Finishing Beef Steers

Previous research (Galyean et al., 1997) indicated that daily gain and feed efficiency were improved when finishing beef steers were fed graded levels of ruminally protected choline (RPC; .25, .5, and 1% of dietary DM). Responses were cubic (P < .10) in nature, with an 11% increase in daily gain and a 6.8% improvement in feed efficiency for .25% RPC vs the control diet, but no effect on gain or efficiency with the 1% RPC diet vs the control diet. Subsequent research at Kansas State University (Bindel et al., 1998) confirmed the findings of Galyean et al. (1997) and suggest the need for further research to evaluate the efficacy of dietary levels of RPC at less than .25% of the dietary DM and to evaluate additional sources of RPC. This research is needed to allow beef cattle feedlot managers and nutritionists to make informed decisions on the use of RPC in feedlot cattle diets.