Influence of Branched-Chain Amino Acid Balance in Broiler Diets

Abstract

Two experiments were conducted to evaluate the influence of balance among the branched-chain amino acids Leu, Ile, and Val in broiler diets when levels of these amino acids were deemed adequate. High levels of Leu were obtained by either increasing the quantity of corn gluten meal (disproportionately high in Leu relative to Ile and Val) or by supplementing a corn-soybean meal diet with crystalline Leu. Supplements of Ile and Val were added to aliquots of the high Leu diets to maintain Ile:Leu:Val ratios similar to those observed in diets at the lowest level of Leu. Live performance and organ weights of chicks grown to 21 d on these diets were evaluated. The results of the present studies suggest that an antagonism among or between Leu, Ile, and Val is not likely to result in depressed performance of broilers fed practical type diets when levels of these amino acids are above their minimum requirements. The primary effect noted in these studies was a reduction in feed intake as the level of corn gluten meal increased, attributed primarily to changes in texture of the diet. Further research is needed to evaluate the potential impact of an imbalance in diets with reduced levels of crude protein where one or more of the branched-chain amino acids may be at minimal dietary levels with high levels of Leu from corn protein.