Terminação de cordeiros sob pastejo com teores crescentes de proteína

Abstract

The supplementation of lambs on pasture suggests circumvent the nutritional deficiencies of forage. Knowing the level of consumption and the protein content of the supplement promotes production regarding product quality and profitability. The objective of this study was to evaluate the levels of crude protein in supplement under the production of lambs - undefined breed, recreated to grazing. A total of 50 lambs with initial weight 20.20 ± 2.94 kg raised on pasture of Napier grass for 75 days. The treatments were four levels of crude protein supplement (8, 16, 24 and 32%) and a control group that received only mineral salt for sheep. The mixing multiple was composed of common salt, mineral supplement suitable for sheep, soybean meal, ground corn and limestone. The energy level in the supplement was 1.8 Mcal/kg for all treatments, except for the control group. It was evaluated parameters related to the dietary intake of forage and supplement, animal grazing behavior, daily gain, slaughter weight, carcass characteristics and meat quality. The slaughter occurred at 75 days of experiment and was determined the weight and cut yield. Samples of Longissimus dorsi muscle were collected to evaluate the color, pH and traits related to meat quality as composition, loss weight by cooking and tenderness. The final weight, total average gain, body weight at slaughter and empty body weight were significantly better for animals receiving supplements containing 8, 16, 24 and 32% CP, when compared with the control treatment (0% CP). The protein supplementation improves slaughter weight, fat cover and with that, decreases the weight losses for defrosting.