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

Modern poultry genotypes produce more body heat due to their greater metabolic activity accompanied with tropical environment often worsens the situation. Nutritional interventions play an important role in ameliorating the negative effects of heat stress which will be more economical and sustainable approach.

In order to evaluate the role of osmolyte (betaine) as a heat ameliorating agent, an experiment was conducted in broiler chicken 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. 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 1.5 g/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. Villi structure was more improved in 1 g/kg dose level. The present study confirms that, supplementation of betaine at 1g/kg levels could significantly improve overall growth performance, gut morphology and welfare in heat stressed broiler chickens.