Quantification of the spatial distribution of surface temperatures of broilers.

Thermal comfort is of great importance in chickens to preserve body temperature homeostasis during the growth period and during environmental thermal challenges. Because surface temperatures contribute much to thermal comfort, this research is aimed at studying spatial distribution of surface temperatures of broiler chickens. For this purpose, temperatures of 26 different parts on the chicken body surface were measured using thermography during the growth period of 6 wk. It was observed that there were significant differences in spatial distribution of broiler surface temperatures. The greatest temperatures were measured at the positions with little or no feathering (i.e., cheek, skull, and inner thigh). The least temperatures were observed on the places with thickest feather cover (i.e., wing and breast). The surface temperatures decreased as a function of age from approximately 36 to 28 degrees C. The spatial temperature range on the surface of the bird varied from 6 degrees C in wk 1 to 15 degrees C on wk 6. Temperature differences between the surface of the chicken and its surroundings were also studied, and it was found that in the range of 1 to 6 wk the age of the bird had significant effects on temperature difference (P < 0.0001). The temperature difference between the surface of the chicken and environment was at a maximum on wk 4 during the growth period of 6 wk.