Aspectos ambientais, produtivos e econômicos do aproveitamento de resíduo úmido de cervejaria na alimentação de cordeiros em sistema de confinamento

Abstract

The objectives of this work were to evaluate the generation and the pollutant power of brewery residues and to determinate the productive and economic aspects of the use of this residue as replacement to the concentrate meal on the diet of lamb in feedlots as the finishing phase. Twenty-five male, non-castrated Texel lambs, single born, weaned at the age of 69 days were used. They were offered diets with five levels (0%, 25%, 50%, 75%, and 100%) of brewery residues replacing the meal concentrate. The lambs were slaughtered 77 days after the installation of the experiment. For every 100 kg barley grain used as source material, 132.02 kg of brewery residue was generated. The brewery residue was classified as Class IIA and showed pH value of 4.63, for BOD5 of 659 mg O2 L-1 and for COD of 10769.9 mg O2 L-1, revealing that this residue has high pollutant charge. There was a quadratic effect on the dry matter food intake and a decreasing linear effect on the daily weight gain and the cold carcass weight with the increase in the level of brewery residues. The economical analysis showed that there was a linear decrease in the feed costs with the increase of the quantity of brewery residues in the diets. However, no effect of the inclusion level of the brewery residues on the profit related to live animal or carcass sales was verified.