Effects of Body Condition, Initial Weight, and Implant on Feedlot and Carcass Characteristics of Cull Cows

Feeding cull cows an energy-dense diet can increase amount and quality of marketable product. Furthermore, implanting cull cows with steroid implants may improve BW gain, feed efficiency, carcass traits, and overall eating quality. Therefore, objectives of this study were to determine effects of implant, initial BW, and body condition score (BCS) at the beginning of the study, on feedlot performance and final live animal and carcass weights, and carcass characteristics of cull cows fed a high-concentrate diet for approximately 90 d. One-half (68) of the cows were allotted to implant treatment (Synovex-Plus®) by initial BW and BCS. Cows were fed a warm-up diet (50 to 60% concentrate, DM basis) for 14 d and then fed a finishing (80 to 85% concentrate, DM basis) diet for the remainder of the study. Variations in initial BW of cows were associated positively (P<0.10) with final BW, hot carcass weight, longissimus area, and yield grade. Initial BCS had a positive affect (P<0.10) on fat thickness but did not influence (P>0.10) ADG, final BW, or other carcass traits. Implant influenced (P<0.05) both feedlot and carcass characteristics; implanted cattle had 18 kg greater final BW, 0.22 kg greater ADG, 18 kg greater carcass weight, 8.6 cm 2 larger longissimus area, 27 units (100 units per marbling score) less marbling and 0.24 units less yield grade. Initial BW, BCS, and implanting influence feedlot performance and carcass characteristics of cull cows.