Eighty six young bulls were used, divided into four genetic groups: Nellore (n=20), Canchim (n=17), ½ Canchim ×Nellore (NC) (n=25) and ¾ Canchim ×Nellore (TQ) (n=24). The animals were weighed every 28 days to evaluate the average daily gain (kg/day), dry matter intake (kg/day) and feed conversion. When the animals reached slaughter weight (450 kg) and fat thickness greater than 4 mm, were slaughtered to evaluate the rib eye area (cm²), subcutaneous fat thickness (mm), marbling, shear force, ether extract (%) and total cooking losses. The Nellore group fitted correctly into the proposed system, showing similar performance when compared to the CN group (1.18 and 1.29 kg/day for Nellore and CN, respectively) and feed conversion (6.90 and 7.04 for Nellore and CN, respectively). The dry matter intake (kg/day) differed among all groups (11.82, 9.39, 8.90 and 8.31 for Canchim, TQ, CN and Nellore, respectively). The carcass weight (kg) was higher in the Canchim group (291.14) than the other groups (250.74, 246.64 and 244.18 for TQ, CN and Nellore respectively). Although the carcass dressing percentage of the Nellore group (58.75%) was the highest, this group had the lowest yield of commercial cuts in the hindquarter especially for the sirloin (10.22, 11.55, 11.64 and 11.18% for Nellore, Canchim, TQ and CN, respectively). The shear force values indicated that the slaughter of young animals can assure tender beef regardless of the genetic group.
feedlot; feed to gain ratio; rib eye area; subcutaneous fat thickness; tenderness
