Dietary supplementation of probiotics in poultry exposed to heat stress – a review

Heat-related stress has become a serious problem in poultry industry along with the global temperatures rise. Heat stress causes detrimental effects on physiology, immunology and microbiology resulting in abnormalities and impaired performances of birds. Several nutritional strategies have been conducted to counteract the detrimental effects of heat stress in poultry, including dietary supplementation of probiotics. This strategy has been proposed to ameliorate the intestinal ecosystem, physiological conditions and immune system, leading to the improved performance and health of birds subjected to heat stress. This review presents the potential benefits of probiotics against heat stress in poultry from the viewpoint of intestinal microbial ecology, morphology and structure, physiological conditions, immune system and production performances. The possible mechanisms through which probiotics may give beneficial impacts on heat-stressed birds are also discussed along with the data reporting the possible drawbacks of using probiotics in heat-stressed poultry.