Utilização de gordura protegida na alimentação de cabritos Boer + Saanen

Abstract

The aim of this study was to evaluate the intake, the production parameters, the digestibility of dry matter and the nutrients of diets with increasing levels of metabolizable energy, blood parameters, and economic analysis of the diets of Boer + Saanen goat kids, finished in feedlot system, as well as to study its carcass characteristics, the proportions of commercial joints, tissue composition, and chemical composition, color parameters and fatty acid profile of the Longissimus thoracis et lumborum muscle. 28 uncastrated male Boer + Saanen goat kids were used, which were slaughtered with 31.95 ± 1.13 kg, assigned to a completely randomized design in four treatments: control with 2.5 Mcal ME/kg DM and the others with 2.6, 2.7 and 2.8 Mcal ME/kg DM, with protected fat to increase the energy density of diets. In order to estimate digestibility, it was used ADFi as internal marker. There were treatment effects (P <0.05) in the intake of dry matter, organic matter, ether extract and non-fiber carbohydrates. It was observed a quadratic effect on the parameters of daily weight gain and feed conversion. Digestibility of NFC and TC showed a linear decrease and CP increased linearly. It was observed a quadratic response in relation to EE digestibility. The serum cholesterol level was influenced by the treatments (P <0.05), showing a linear increase. The economic evaluation showed to be favorable for the diet with 2.5 Mcal ME / kg DM. There was no influence of the treatments (P> 0.05) in carcass quantitative traits, however, the greater thickness fat showed a crescent linear effect. In the fatty acid profile, it was observed a crescent linear effect on the proportion of conjugated linoleic acid, and n-6. Saturated fatty acids, unsaturated, polyunsaturated, n-3 amount and n-6/n-3 ratio, showed a quadratic response. The increase of energy density of Boer + Saanen goat kids diet, through inclusion of protected fat, influences the intake and digestibility of dry matter and nutrients, however it doesn't improve the production performance, proportions of commercial joints, tissue composition, chemical composition and color of Longissimus thoracis et lumborum muscle, however, it increases the proportion of linoleic acid and improves the n-6/n-3 ratio in meat of Boer + Saanen goat kids.