Effects of Zeranol-Implantation Periods on Palatability of Longissimus Steaks from Young Bulls and Steers2

Fifty-five fall-born, Simmental-crossbred, male calves were allotted at birth to one of five treatments: bulls castrated at 5 mo and implanted from birth to slaughter (ST); bulls implanted from birth to slaughter (BI-BS); bulls implanted from birth to weaning (BI-BW); bulls implanted from weaning to slaughter (BI-WS) and non-implanted control bulls (CB). Implanted calves received 36 mg of zeranol at approximately 100-d intervals. Calves were fed a high-concentrate diet from 8.1 mo of age to an average slaughter age of 17 mo. Longissimus steaks (LS) were evaluated for palatability traits by both a trained sensory panel (TSP) and a take-home consumer panel (CP). Conclusions from both panels were similar. The TSP found LS from ST to be juicier (P less than .05) than LS from all bull groups, and to be more tender (P less than .05) than LS from BI-BW and BI-WS. The CP found LS from ST to be juicier, more tender and more acceptable (P less than .05) than LS from BI-BW, BI-WS and CB. Steaks from BI-BS were more tender (P less than .05) than LS from BI-WS and CB. Steaks from BI-BS and BI-BW had lower (P less than .05) shear values than LS from CB, but LS from ST had lower (P less than .05) shear values than LS from all bull groups.(ABSTRACT TRUNCATED AT 250 WORDS)