Parts Yield of Broilers Reared Under Cycling High Temperatures

Two studies were conducted to examine effects of cycling high environmental temperature during the growing period on subsequent carcass yield. Commercial broilers were reared form 23 to 49 days of age at either 23.9 C constant temperature or 23.9 to 35 C cycling high temperature. Birds in the heat stress environment were exposed to 8 h of 23.9 C, 4 h of 23.9 to 35 C, 4 h of 35 and 8 h of 35 to 23.9 C. Birds grown at elevated temperatures weighed up to 21% less (P < .05) than those raised in a thermoneutral growth environment, with this weight difference being pronounced in both sexes. Whole carcass weight and carcass part weight from birds at 23.9 C were greater than from those in the cycling high temperature environment.