Mitigation of Heat Stress in Broiler Chickens during Hot Summer Seasons through Betaine Hydrochloride Osmoprotectant Intervention

Abstract

Abstract Modern poultry genotypes produce more body heat due to their greater metabolic activity and in tropical country; high environment temperature often worsens the situation. Heat stress is a major concern for the poultry industry as it adversely affects growth as well as immune functions. Nutritional interventions play an important role in ameliorating the negative effects of heat stress and will be more economical approach. In order to evaluate the role of osmolyte (betaine) as a heat ameliorating agent in broiler chicken, an experiment was conducted with gradient levels of 0, 0.5, 1.0 and 1.5 g/kg for a growing period of 42 days. Each group comprised 48 birds in six replicates of 8 each. All birds were maintained under standard managemental conditions. Thermo-Humidity Index value ranged 85–87 throughout the experimental period. Production performance, immunity, gut morphometry, hemato-biochemical and stress indicators were studied. Supplementation of betaine significantly improved production performance as well as breast meat yield (P < 0.05). Supplementation (1 and 1.5g/kg) significantly (P < 0.01) improved both the humoral and cellular immunity. Betaine supplemented groups also depict significant (P < 0.01) rise in hemoglobin and relative immune organ weight. Addition of betaine to basal diet significantly (P < 0.01) increased the villus length and also lowered H:L ratio, with better ALT and AST values than the control. The dose level of at 1 and 1.5g/kg improve all the parameters but villi structure was more improved in 1g/kg dose level and also it is economical than 1.5g/kg dose level. To conclude present study confirms that, the supplementation of betaine at 1g/kg levels could significantly improve overall growth performance, gut morphology and welfare in heat stressed broiler chickens.