REALIMENTATION OF CULL BEEF COWS. I. LIVE PERFORMANCE, CARCASS TRAITS AND MUSCLE CHARACTERISTICS

ABSTRACT

The objective of this study was to determine whether culled beef cows fed a high-concentrate diet (FED) would have improved live performance, carcass traits and muscle characteristics compared with forage fed (CON) cows. In addition, ractopamine (RAC) supplementation was evaluated for added benefits over high concentrate alone. Live weight, average daily gain, hot carcass weight, ribeye area, marbling, quality grade and carcass fat measurements increased (P ≤ 0.05) by realimentation. As a percent of hot carcass weight, muscle yields did not differ (P > 0.05). Lipid content increased (P ≤ 0.05) in 5 out of the 10 muscles from FED cows. Cows fed ractopamine showed some numeric improvements over feeding alone, but few statistical differences (P > 0.05). This may result from variability associated with cull cows, and warrants investigation into the best dose/duration for ractopamine. However, realimentation by itself was able to improve cull cow quality.

PRACTICAL APPLICATION

The U.S. beef industry continues to explore new avenues to enhance undervalued sectors of the production system. Through realimentation, cull cow quality can be improved. The data presented herein demonstrate that feeding a high-concentrate diet to cull cows increases both live and carcass weights. In addition, high concentrate-fed cull cows display more marbling and whiter fat cover than those fed at maintenance level. Qualification for premium programs, heavier weights and overall higher quality may lead to increased value for this underutilized sector of the beef industry.