One experiment was conducted to determine whether low - protein amino acid fortified diets would prevent the reduction in broiler performance. Chicks were fed the experimental diets from 1 to 56 days of age. Regardless of crude protein (CP) content, all diets were formulated to be isocaloric and to meet National Research Council requirements 1994 of essential amino acids as well. In starting Period (0 to 21d) body weight gain (BWG) and feed intake (Fl) significantly decreased as CP levels decreased. In growing and finishing periods, BWG, Fl and Feed conversion Ratios (FCR) were not significantly influenced by dietary CP levels. Live body weight (at 56 days)were not significantly affected by dietary CP levels. Abdominal fat deposition (AFD) significantly increased as dietary CP level decreased. Whole breast yields and carcass yields was not affected by dietary CP levels.
)