The Influence Of Dietary Energy, Protein And Copper Levels On The Sulphur Amino Acid Requirements Of Broiler Chickens

Abstract

Three experiments were conducted with male broiler chicks to determine the influence of dietary metabolisable energy ( ME ) , crude protein (CP) and copper (Cu ) levels on the total sulphur amino acid (TSAA) requirement of broilers both during the starter ( 0-3 wk) and t he grower periods ( 4-6 wk) reared in the tropics . In all the experiments the parameters used to evaluate the TSAA requirements are body weight gain , feed : gain ratio and carcass composition. In the first experiment , two factorial arrangements of three ME levels ( 3000 , 3200 and 3400 kcal /kg ) x four level sof TSAA ( 0 . 73 , 0 . 83 , 0 . 93 and 1. 03% ) and the same three ME levels ( 3000 , 3200 and 3400 kcal /kg ) x four levels of TSAA ( 0 . 65 , 0.72 ,0.79 and 0.86% ) were used for t he starter and the grower periods,respectively . The results showed significant differences ( p< . 05 ) in body weight gain and feed : gain ratio of the broilers within creasing dietary TSAA levels both in starter and grower periods. There were no significant interaction ( p< . 05 ) between dietary ME and TSAA levels for the performance , with the exception for feed in take of starter broilers . It indicated that for the starter period , a TSAA of 0 . 93% produced the best performance regardless of energy levels while for the grower period the requirement of TSAA at both 0 . 79 and 0 . 86% were suggested . The results further showed that dietary energy levels had no effect on the TS AA requirement of the broilers.