ABILITY OF BROILERS TO RESIST HEAT FOLLOWING NEONATAL EXPOSURE TO HIGH ENVIRONMENTAL-TEMPERATURE

Two trials were conducted to determine whether heat exposure of neonat al broilers had any effect on their growout performance or on their mo rtality during heat exposure later in life. Broiler chicks, 5 or 6 d o ld, were exposed to 36.1 C for 24 h in environmental chambers. At 47 d in Trial 1 and at 42 d in Trial 2, the broilers were exposed to 37.8 C for 6.5 h in Trial 1 and 8 h in Trial 2. Early heat exposure did not influence resistance to later heat exposure as measured by mortality. Also, early heat exposure did not affect body weight gain, feed effic iency, or growout mortality.