The effects of feed form, protein profile, energy level, and gender on broiler performance in warm (26.7 C)...

Two dietary energy levels, 3032 and 3109 kcal ME/kg, and four protein levels of approximately 17, 18, 19 and 20%, were used to formulate eight grower-finisher rations used in four feeding regimens used in both mass and crumble form fed to broilers in a warm (26.7 C) environment. The protein levels were established by specific lysine: energy ratios with methionine plus cystine at a constant percentage of lysine. Best overall broiler performance was obtained with a feeding regimen using the higher energy level with high-protein profile in crumble form; feed conversion for this regimen was improved 5.4% and body weight 3.2% over the poorest performing diet, which was the lower energy diet with low-protein profile in mash form. Overall, crumbling improved feed conversion 1.5% and increased body weight 2.2%, the high-protein profile improved feed conversion 2.0%, and increasing metabolizable energy from 3032 to 3109 kcal/kg improved feed conversion 2.2%. Feed conversion for males was 3.3% better than for females.