EFFECT OF FEEDING LOW PROTEIN DIETS SUPPLEMENTED WITH SYNTHETIC AMINO ACIDS ON BROILER BIRDS

Abstract

An eight-week study was conducted to determine the effect of feeding low protein diets supplemented with synthetic amino acids to broiler birds. Ninety six unsexed day-old chicks (Hubbard strain) were used for the study. The birds were randomly divided into 6 groups of 16 birds each. The groups were randomly assigned to 6 diets in a 2x3 factorial arrangement involving 3 levels (18, 20 and 22) of crude protein and two levels (0.25 and 0.5% levels of lysine in the starter phase and 3 levels (18, 19 and 20) of crude protein and two levels (0.25 and 0.5%) level of lysine in the finisher phase. Each treatment was replicated 2 times with 8 birds per replicate. Results showed that in the starter phase, final body weight (FBW), total weight gain, daily feed intake, total feed intake, average daily weight gain, feed conversion ratio, protein efficiency ratio and cost of feed per kg gain were all significantly (p <0.05) affected by dietary treatments. Birds on treatment 3 had similar final body weight value, total weight gain, average daily weight gain (ADWG) and FCR with those on treatment 1 (control). Birds on treatment 3 had the least cost per kg gain. In the finisher phase, final body weight (FBW), total weight gain, daily feed intake, total feed intake, average daily weight gain and cost of feed per kg gain were all significantly (p < 0.05) affected by dietary treatments. Birds on treatments 1 and 3 had similar FBW, ADWG and cost of feed per kg gain. Birds on treatment 3 had the highest total weight gain. It was concluded that in order to achieve substantial economic savings without affecting the growth performance of broilers, 20% CP diet supplemented with 0.25% lysine and 19% CP diet supplemented with 0.25% lysine should be fed to broiler starters and finishers, respectively.