Alternativas para a terminação de bovinos em pastejo em relação ao confinamento

Abstract

The objective of this study was to evaluate the effect of finishing systems for grazing cattle in relation to feedlot, on productive performance and carcass and meat characteristics. Four treatments were evaluated, which were arranged in a completely randomized design, being a model in conventional feedlot, with 20% grass silage and 80% concentrate, and another three in grazing, combining the concentrate offer, with the stocking rate, the combinations being tested: low (0.5% and 5.0), half (1.0% and 7.5) and intensive grazing termination IGT (2.0% and 15.0), respectively, supply of concentrated, based on body weight, and stocking rate expressed in heads/hectare. 36 Nellore heifers with 277 ±30 Kg of body weight and fifteen months of age were used, nine animals per treatment. The forage mass was not restrictive for the free consumption of the animals during the experimental period, thus, in the IGT system there was less forage supply with 1.35 and disappearance of 29.71% of forage mass and 92.72% of blade leaf. It was observed that the consumption of concentrate varied from 1.22 Kg DM/day in the low system to 4.38 Kg DM/day in the IGT system and that this had no difference for the feedlot system. In the same way, the termination systems influenced the average daily gain of the animals with 0.53; 0.76; 0.79 and 0.82 Kg/day, respectively, for low, half, IGT and feedlot systems. The final live weight of the animals did not differ between systems. The values of daily carcass gain - DCG of the IGT animals were more than twice the low system, 0.582 and 0.254 Kg/day, respectively. In addition to the DCG, both the subcutaneous fat thickness - SFT that ranged from 3.87 to 5.54 mm, and the carcass gain yield, which was below 58% for animals in the low system and above 80% for the animals in the IGT and feedlot systems were altered by the systems. However, most of the qualitative characteristics of carcass and meat were not influenced by the termination systems. The IGT system provided the animals with high productivity, with better utilization of area, matching the feedlot system, without affecting most of the qualitative characteristics of the carcass and meat of heifers.