PSVIII-16 Effects of an aggressive implant strategy on fabrication yields of Jersey steers

Abstract Jersey steers (n = 12) were used to evaluate the effects of an aggressive implant strategy aimed to improve value in historically low-value, dairy steers. Steers were fed for 420d after being randomly allocated to one of two treatments: IMP (Revalor-200 administered at d0-d70-d140-d210-d280-d350) or CON (negative control). Steers were harvested after 420d and were fabricated after chilling into primals, subprimals, and trimmed lean, fat, and bone components. Data were analyzed via independent t-test. Primals from IMP cattle were a greater percentage of round (P = 0.02; 22.93 vs 21.55%) whereas CON cattle were a greater percentage of rib (P = 0.01; 9.56 vs 8.81%) and plate (P = 0.06; 9.51 vs 8.43%). Subprimals were greater for IMP than CON in the brisket (P < 0.01; 2.55 vs 2.03%), bottom sirloin tri-tip (P = 0.04; 0.75 vs 0.64%), bottom round (P < 0.01; 3.23 vs 2.74%), and eye of round (P < 0.01; 1.35 vs 1.04%), with tendencies for differences in knuckle (P = 0.09; 3.01 vs 2.78%) and heel meat (P = 0.08; 1.20 vs 1.09%). Muscle to bone ratio was similar (P = 0.31) between CON (2.34:1) and IMP (2.54:1), whereas muscle to fat ratios were greater (P = 0.02) in IMP (4.05:1) than CON (2.68:1). Total carcass fat was greater in CON than IMP (P = 0.03; 20.19 vs 15.07%), total red meat yield was numerically larger in IMP than CON (P = 0.13; 59.02 vs. 53.88%), yet total bone was similar between treatments (P = 0.94; 22.97 vs 22.83%) cattle. These data indicate an aggressive implant strategy on Jersey steers can increase muscle to fat ratio and fabrication yields in the round and brisket, while reducing total carcass fat.