Zinc methionine supplementation during the summer season enhanced the growth, immunity, antioxidants and zinc retention of broiler chickens

The current study is aimed for determining the optimal dose of zinc methionine (Zn-met) in broiler birds during the summer season in order to improve growth, immunity, stress tolerance, and concentration of Zn in vital organs. Total of 240 number of one day-old Vencobb chicks were randomly allocated into six dietary groups, each group consisting of five replicates of 08 birds. The dietary interventions consisted of: T1: Basal diet; T2: Basal diet + inorganic Zn (ZnSO4) 80 ppm; T3: Basal diet + Zn-met 20 ppm; T4: Basal diet + Zn-met 40 ppm; T5: Basal diet + Zn-met 60 ppm, and T6: Basal diet + Zn-met 80 ppm. The trial lasted for 5 weeks. The weight and FCR under T5 and T6 increased significantly. Antibody titres were significantly increased in treated chickens. The experimental chickens in all the Zn treated groups showed a significant increment in catalase and superoxide dismutase activities with a decreased lipid peroxidation rate. Zn concentrations in blood along with different organ samples viz. liver, kidney, and breast muscle were significantly higher in all the supplemented birds. There were no observable histological abnormalities evident in liver and kidney tissues in the T5 and T6 groups with the highest Zn-met dose. It was concluded that adding Zn at 60 ppm above basal level resulted in improved performance of the chickens along with protection from heat stress.