Determining the Effect of Heat Stress on Chicken Performance, Welfare, and Probable Mitigation Strategies

The poultry industry worldwide provides chicken meat and eggs, one of the most important protein sources among animal foods. The impact of climate change, which increases heat stress and harms the performance and welfare of the chicken, is a problem for the industry. Since chickens can only endure a small range of temperatures when under the effects of heat stress, this environmental stress has posed the greatest challenge to the worldwide poultry business. Heat stress lowers feed efficiency, body weight, feed intake, and egg production and increases chicken mortality. Severe heat stress hurts feed intake, growth rate, mortality, egg production, hatchability, and other production qualities that contribute to the economic viability of the poultry industry. Heat stress generally stimulates the neuroendocrine system, activating the hypothalamic-pituitary-adrenal axis and increasing corticosterone concentrations, influencing metabolism and immunological responses. Some mitigation strategies employed to reduce the impact of heat stress on chickens include modifying the environment by providing adequate ventilation and cooling systems and adjusting their nutrition to help lower the body's metabolic heat output and keep electrolyte levels stable under high-stress, high-temperature circumstances. Dietary plans and feed formulations containing important elements such as selenium, zinc, calcium, vitamin E, vitamin C, vitamin A, electrolytes, essential amino acids, and plant extracts help combat all types of stress in birds and boost their immunity. It is essential to gain a deeper understanding of the interplay between various environmental factors, particularly heat stress, and their subsequent effects on chicken performance, behavior, welfare, and reproduction, as well as the most effective management and nutritional strategies to mitigate the negative effects of various stresses in chickens. This review seeks to provide a complete overview of the effects of heat stress on the performance, welfare, and production of chickens and to analyze the scope and effectiveness of probable mitigation strategies to ameliorate its hazard.