Genotype by Diet Interactions in Body and Abdominal Fat Weight in Broilers

Three experiments were conducted to study early growth, feed and water intake, feed efficiency, abdominal fat, and feathering in commercial broilers (C) and unselected (AC) chickens fed high-protein (P) or high-energy (E) diets. Commercial birds were heavier, consumed more feed and water, had better feed efficiency, higher abdominal fat levels, and poorer feather scores than AC birds. Body weights of C birds fed the E diet were, in general, greater than BW of contemporaries fed the P diet. However, AC body weights did not respond in a similar manner. Feed intake patterns were similar to those for BW. Water intake and water to feed ratio values were consistently greater in both AC and C birds fed the P diet. The C birds had higher percentages of abdominal fat than AC birds, and C birds fed the E diet had higher abdominal fat (89%) than those fed the P diet; the difference was only 33% in the AC stock and this resulted in significant (P<.05) stock by diet interactions. Diet had little influence on feathering in AC birds, whereas C birds that received the E diet had significantly (P<.05) poorer feathering than those that received the P diet.