Understanding the Needs of Branch Chain Amino Acids in BroilerProduction

摘要

Valine is the 4 limiting amino acid for broilers fed diets utilizing amino acid contributing ingredients of vegetable origin (Thornton et al., 2006). Ideal amino acid ratio concept is a popular method to express amino acid requirements relative to lysine. Utilizing L-valine in concert with ideal amino acid ratio concept in diet formulation allows nutritionists to meet an optimum digestible valine to lysine ratio while decreasing nitrogen excretion and maintaining cost effective diets. Formulating diets at a digestible valine to lysine ratio below the broiler's need for valine limits their genetic potential in meeting performance objectives. Digestible valine to lysine ratio has been reported to vary among various production periods with ratios ranging from 0.74 to 0.78 (Corzo 2007, 2008; Rostagno et al, 2011). Corzo et al. (2011) has reported acceptable performance with the inclusion of L-valine into broiler diets. Price spread among cereal grains, supplemental oil/fat, and protein meals determinesthe value of L-valine. During times of high fat prices and a wide spread of grain and protein meal prices will led to the inclusion of L-valine supplementation. Isoleucine will become the pressure point in diet formulation with the inclusion of L-valine. Understanding the digestible isoleucine needs of broilers is important to optimize the rate and efficiency of growth when including L-valine in the diet. This presentation will review research on dietary valine and isoleucine of broilers to optimize growth performance and processing yields.