Abstract
This study was conducted to examine the negative impact of heat stress on broiler chickens and laying hens and to explore the potential of dietary functional nutrients in mitigating these effects. Heat stress in poultry was found to negatively influence productivity and immune response while simultaneously increasing mortality, internal nutrient requirements, and stress-related hormones levels. These physiological changes led to increase of blood glucose levels, respiration, muscle tension, and neural sensitivity. To address these heat stress-induced challenges, the inclusion of functional nutrients in poultry diets may offer several benefits, including: (i) attenuation of heat stress responses, (ii) enhancement of immune function, (iii) improvement of antioxidant capacity, (iv) maintenance of productivity, and (v) promotion of intestinal health. These functional effects are expected to enhance disease resistance and overall productivity. However, the effectiveness of dietary functional nutrients may differ based on the specific type of additive, the method of administration, and physiological and environmental conditions. Therefore, it is crucial to optimize the selection and application of functional nutrients to the particular needs and context of each poultry farming operation. In conclusion, this study provides foundational insight and strategic recommendations for practical use of dietary functional nutrients to reduce the impact of heat stress in broiler chickens and laying hens.