Carcass traits of steers from two breeding systems, straightbreds (S) and F1 crossbreds were studied. The S breeding system included the Charolais (C) and the Nellore (N) breeds and the F1 included 1/2 C + 1/2 N and 1/2 N + 1/2 C crosses. A total of 463 steers, born from 1984 to 1996 were used. The crossbred steers were superior to the purebreds in slaughter weight, carcass weight, conformation, carcass length, cushion thickness, arm perimeter, sidecut percentage, fat thickness and Longissimus muscle area, and the heterosis levels, in percentage, were 10.7, 11.6, 3.8, 2.9, 2.5, 2.8, 3.1, 14.2 and 8.0, respectively. Straightbred animals were superior than the F1 in sawcut percentage and bone percentage. Between the straightbreds the C group showed higher slaughter weight, carcass weight, conformation, carcass length, cushion thickness, sidecut percentage, sawcut percentage and Longissimus muscle area, but they were inferior than the N group in dressing percentage, leg length, arm length, forequarter percentage and subcutaneous fat thickness. Crossbreeding between C and N resulted on positive heterosis for important commercial traits.
Bos indicus; Bos taurus; conformation; dressing percentage; fat thickness
