Effect of total sulfur amino acids in corn-cassava-soybean diets on growth performance, carcass yield and blood chemical profile of male broiler chickens from 1 to 42 days of age

The experiment was conducted to determine the effects of total sulfur amino acid (TSAA) in diets on growth performance, carcass yield and blood chemical profile of commercial male broiler chickens from 1 to 42 days of age. Six graded levels of TSAA were fed during the starter (1-21 days of age) and the grower (22-42 days of age) periods at 61, 84, 100, 105, 110 and 115% of commercial recommendation. The experiment was a completely randomised design. In all, 1050 commercial male broiler chicks (Ross 308) were divided into six treatments, and each treatment consisted of seven replicates of 25 chicks each. Body weight gains of chicks that received TSAA at 100% of commercial concentrations were significantly greater than those that received the recommended National Research Council concentrations (84% of commercial levels, P < 0.05). The best feed-conversion ratio and feed cost per gain were found at the commercial recommendation level. Nonetheless, broilers that were fed TSAA at concentrations higher than the commercial recommendation levels did not exhibit positive effects on growth performance. With respect to carcass yield, the breast meat yield was increased by increasing TSAA in the diets (P < 0.05), particularly when supplied at commercial recommendation levels, whereas the eviscerated carcass and liver weights were not significantly affected. There was no significant effect of increasing TSAA in the diets on serum triglyceride, uric acid, total protein, albumin and globulin. In conclusion, broilers fed diets supplemented with TSAA at commercial concentrations gave the best growth performance, carcass yields and economic return.