Effects of High Temperature and Humidity on Heat Prostration of Broiler Chickens

Abstract

Tests were conducted to determine the effects of humidity, body weight, and acclimation on mortality due to heat prostration when market-size male broiler chickens were exposed to an ambient temperature of 40.6°C. Results indicate that acclimation temperature varied diurnally between 23.9° and 32.2° or 35°C., compared to a constant 21.1°C., effectively reduced mortality when 8-week-old broiler males were exposed to the high ambient temperature. The humidity level was found to have an important effect on heat prostration. For 8-week-old male broiler chickens, the critical dewpoint temperature when ambient temperature is 40.6°C. was found to be between 21.1° and 23.9°C., where thermal radiation was not a factor. Critical relative humidity for these conditions would be between 33 and 38 percent.