AbstractHeat stress reduces the production performance of chicken leads to immunosuppression and increases the mortality rate in chicken. All the nutritional supplements (e.g. vitamins, zinc, Kcl) have functions in relation to heat stress. Suitable mineral and vitamin premixes can be developed for heat stressed chickens for improved performance, welfare and reducing feed cost. Heat stress increase the serum concentration of ACTH which increase corticosteroid level and in turns reduces the production. Dietary supplementation of vitamin C (200 mg/kg) improved the egg production and egg shell quality in laying hen during summer stress. Ascorbic Acid supplementation (300 mg/kg of diet) improved body weight gain, feed conversion ratio and decreased the mortality in broilers. Dietary supplementation of anti-oxidant vitamins (vitamin E or vitamin C in combination) is helpful to maintain the growth performance, egg production and improvement in egg quality. Vitamin E (250 mg/kg diet) increased serum concentration of T3, T4 and decreased concentration of ACTH thereby production is maintained. Low protein diet (14%) with provision of additional methionine @ 0.44% maintained the production performance of laying hens. Supplementation of Dietary Electrolyte Balance like NaCl, NaHCO3, KHCO3 and NH4Cl (360 m Eq/kg) in heat stress can improve eggshell quality of laying hens. Supplementation of 0.1% KCl with 400 mg vitamin C showed better performance for broilers reared under heat stress. Zinc in combination with vitamin A improves performance and carcass quality of broiler under heat stress.
Keywords: Immunosuppression; Acth; Electrolyte; Vitamin C; Vitamin E; Stress; KCl; Vitamin A.