J. E. Rossi,
S. C. Loerch 1,
F. L. Fluharty
The Ohio State University Department of Animal Sciences
The trial evaluated effects of dietary crude protein level during periods of compensatory growth in steers fed to achieve step-wise increases in growth rate during the feeding period. There were no differences in performance among prescription intake systems when predicted gain was 2.5 lb/d. When predicted gain was 3.0 lb/d, prescription intake steers gained 23% more (3.7 lb/d) than what was predicted. No differences in average daily gain or feed efficiency were observed among prescription intake steers consuming 14% or 16% crude protein diets during this period. Overall feed intake was numerically lower for prescription intake steers despite requiring 14 more days on feed than ad libitum intake steers to reach the slaughter weight. Overall feed efficiency was not different among the five feeding systems (P > 0.57). Prescription intake steers had lower quality grades than ad libitum steers (P < 0.10), but were leaner than ad libitum steers as evidenced by lower (P < 0.10) backfat, yield grades, and carcass fat. Prescription intake steers performed similarly when consuming either a 14% or 16% crude protein diets when predicted gain was 3.0 lb/d. Likewise, performance of prescription intake steers was similar when consuming either a 12% or 14% crude protein diet during the ad libitum intake period. Therefore, feeding diets with crude protein levels higher than 14% when predicted gain is 3.0 lb/d and 12% during the ad libitum intake period to prescription intake steers does not appear to be necessary.
1 For more information, contact at The Ohio State University, Ohio Agricultural Research and Development Center, 114 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691; 330-263-3903, e-mail: loerch.1@osu.edu