Digestibilidade dos aminoácidos e valores energéticos do farelo de girassol e sua inclusão na ração de frangos de corte

Abstract

Five experiments were carried out at Department of Animal Science of Federal University of Viçosa to determine the energetic and nutritional values of sunflower meal (SFM) and the use of SFM in diets for broiler chickens. Two experiments were carried out to determine corrected apparent metabolizable energy (AMEn), through the method of total excreta collection with broiler chickens, and corrected true metabolizable energy (TMEn) and true digestibility of amino acids of (SFM), through the method of forced feeding with cecectomized roosters. The SFM used presented 89.95% of DM, 28.09% of CP, 4,429 kcal/kg of CE, 22.37% of CF, 2.87 of EE, 0.83% of P and 0.30% of Ca. The TMEn and AMEn were 2,200 and 1,983 kcal/kg, respectively. The values of lysine, methionine, and threonine were 0.68, 0.54, and 0.82, respectively. A trial was carried out at to evaluate the performance, carcass yield and cuts, and economic viability of broilers fed with diets containing different levels of inclusion 0, 5, 10, 15, and 20% of SFM. With inclusion of SFM the feed intake reduced linearly in the initial phase and the feed:gain ratio improved linearly in the total period, while there was quadratic effect to feed:gain ratio in the initial phase. No significant differences were found for carcass yield and cuts. And two experiments were carried out in order to evaluate the performance, carcass yield and cuts, and economic viability of broiler chickens fed with diets containing two different levels of SFM (0% and 20%), with or without enzymatic complex supplementation (EC) (Cellulase, β-glucanase, xylanase and phytase) and the values of AMEn of initial diets. No interactions were observed between the SFM and EC on the performance of animals. While the SFM has significantly decreased the feed intake in the initial phase and the total period, weight gain did not differ during these phases. In all stages there was improvement in feed:gain ratio with the use of SFM, probably due to the inclusion levels of oil in the diet, which might have improved digestibility. There was a significant increase in weight gain with the use of EC in the initial phase. There was no significant effect of SFM and EC on carcass yield or cuts.There was no significant effect of adding EC on the values of AMEn of diets, but the addition of EC significantly improved apparent coefficients of metabolizability of phosphorus and calcium.