Abstract
Holstein male calves (36) were allocated at birth to 1 of 3 treatment groups: castrated at 3-7 days of age (steers), intact and untreated and implanted with diethylstilbestrol at birth, 3, 6, 8 and 10 mo. of age. Daily gain and carcass traits of all animals and testicular measurements of bulls and implanted bulls were recorded. Implanted bulls, bulls and steers gained 1.30, 1.19 and 1.08 kg/day. Carcasses from steers were more highly marbled and had higher quality grades than carcasses from either bulls or implanted bulls. Steer carcasses also had more fat cover, more internal fat, smaller rib-eye area and lower cutability than carcasses from bulls and implanted bulls. Physical separation of the 9-10-11 rib section confirmed that steer carcasses contained more fat trim and less lean than carcasses from bulls and implanted bulls. Composition of lean meat did not differ between the 3 groups of animals. Testicular weight was lighter (300 vs. 419 g) in implanted bulls than in intact bulls.