Feeding strategy during growing phase on the performance and carcass traits in beef bulls finished on the pasture

The objective of this study was to evaluate the performance, feed intake, carcass traits, and economic aspects of cattle fed different levels of supplementation during the growing phase (mineral supplementation-MS; low protein supplementation-PS, at 0.15% of body weight (BW); and a high protein-energy supplementation-PES at 0.40% of BW) and finished on the pasture with concentrate supplementation at 1.6% of BW. Ninety bulls were distributed in a completely randomized design and allocated into paddocks predominantly composed of Urochloa brizantha cv. Marandu grass. During the finishing phase, cattle were managed in paddocks of Urochloa decumbens grass. The average daily gain (ADG) and total weight gain during the growing phase were not different between animals fed PS (0.670 kg/day; 57.1 kg, respectively) and PES (0.730 kg/day; 62.4 kg, respectively), but both differed significantly from those supplemented with MS (0.540 kg/day; 45.1 kg). There was no difference between groups for average daily gain and total weight gain during the finishing phase (0.600 kg/day; 48.3 kg) and the same response was observed for carcass yield (55.18%, on average). However, bulls fed PES had higher hot carcass weight compared with those supplemented with MS and PS. Protein supplementation (0.15% of BW) and protein-energy supplementation (0.40% of BW) improved beef cattle performance during the growing phase. However, supplementation during the growing phase has a small impact on cattle performance in the finishing phase, although protein-energy supplementation at the growing phase improves the hot carcass weight and carcass traits during the finishing phase.