R. Bras. Zootec.01/Dec/2009;38(12):2465-72.
Performance and carcass traits of Nellore and Canchim young bulls finished in a feedlot system, receiving diets with sugarcane and two concentrate levels
DOI: 10.1590/S1516-35982009001200024
The objective of this study was to evaluate the performance and carcass traits of young bulls, finished in a feedlot and fed diets with sugarcane (Var. SP 80-1816) and two concentrate levels (40 or 60 % of the DM). Fifteen Nellore bullocks, with approximately 330 kg and 18 months old, and 15 Canchim bullocks (5/8 Charolês ×3/8 Nellore), with approximately 300 kg and 15 months old, were used. The animals were housed in individual pens for a period of 126 days, with the first 21 days of adaptation. The animals were weighed and ultra-sound images were taken at the beginning of the experiment and at every 35 days. A randomized complete design was used in a factorial scheme (2 genetic groups ×2 concentrate levels). There were no significant interactions for any of the evaluated variables. The Canchim animals presented better feed efficiency (0.17 ×0.14) and higher loin eye area gain (19.7 ×13.2 cm2). The 60% concentrate diet improved better daily weight gain (1.44 ×0.98 kg/animal), slaughter weight (499.43 ×460.20 kg), hot carcass weight (265.39 ×244.70 kg) and hindquarter weight (129.74 ×118.68 kg). The Canchim animals presented larger loin eye area (80.89 ×66.85 cm2) and the Nellore animals presented thicker backfat (5.5 ×3.2 mm). Diets with 60% concentrate are better for finishing cattle with high potential for liveweight gain than diets with 40% concentrate.
Keywords: backfat; bullocks; feed efficiency; hindquarter; rib eye area; weight gain