Fabrication yields of serially harvested calf-fed Holstein steers fed zilpaterol hydrochloride

Holstein steers (n = 110) were fed zilpaterol hydrochloride (ZH) for 0 or 20 d before slaughter during a 280-d serial harvest study. Cattle were harvested every 28 d beginning at 254 d on feed (DOF) and concluding at 534 DOF. After slaughter, carcasses were chilled for 48 h and then fabricated into boneless closely trimmed or denuded subprimals, lean trim, trimmable fat, and bone. Inclusion of ZH increased cold side weight (CSW) by 10.3 kg (P < 0.01; 212.7 vs. 202.4 kg [SEM 1.96]) and saleable yield by 10.4 kg (P < 0.01; 131.9 vs. 121.5 kg [SEM 1.16]) in calf-fed Holstein steer carcasses. Additionally, saleable yield as a percentage of CSW increased (P <= 0.01) by 2.19% (62.64 vs. 60.45% [SEM 0.22]) for cattle supplemented with ZH. Subprimal weights were heavier (P <= 0.05) from cattle that received ZH except for the bottom sirloin ball tip, back ribs, and outside skirt regardless of slaughter endpoint. Yield of top round, bottom round, and knuckle was increased (P <= 0.01) following ZH supplementation by 0.37, 0.24, and 0.18%, respectively. Yield of the top sirloin butt, strip loin, and tenderloin was increased (P <= 0.01) concurrent with ZH supplementation by 0.18, 0.11, and 0.09%, respectively. Regarding the rib primal, the rib eye roll tended (P = 0.08) to had increased yield (2.80 vs. 2.72% [SEM 0.03]) with ZH supplementation; both back ribs and blade meat exhibited increased (P <= 0.04) yields of 0.04%. Relative to the chuck primal, increased (P <= 0.03) yields of shoulder clod, pectoral meat, and mock tender were observed (0.13, 0.07, and 0.04%, respectively). Yield changes for subprimal brisket, plate, and flank were limited to increased (P < 0.01) proportion of flank steak and elephant ear (cutaneous trunci), 0.07 and 0.04%, respectively. Feeding duration notably altered (P <= 0.01) weights and percentages of all subprimals except the brisket. Saleable yield increased (P <= 0.01) by 0.192 kg/d with additional DOF. Moreover, trimmable fat and bone increased (P <= 0.01) by 0.146 and 0.050 kg/d, respectively. These data illustrate improved saleable meat yields for calf-fed Holstein steers supplemented with ZH and provide the beef industry knowledge of fabrication yield changes throughout a wide range of harvest endpoints.