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

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.