Effect of betaine on performance and intestinal morphology of broiler chicks under heat stress

This study was conducted to determine effects of betaine supplementation on growth performance and intestinal morphology of broiler chicks subjected to heat stress condition. Two hundred day-old male broiler chicks (Ross 308) were used in a completely randomized design with four dietary treatments. Each dietary treatment replicated five times with 10 birds per replicate. The dietary treatments consisted of a basal diet and the basal diet supplemented with 0.05, 0.1 and 0.2 % of betaine. The experimental diets were offered to chicks under heat stress condition (32±1ºC from 9 AM to 5 PM) during the final period of rearing (25 to 42 days of age). The results did not show any significant effect for the dietary treatments on feed intake and body weight gain, but betaine addition at the levels of 0.1 (2.001) and 0.2% (1.98) decreased feed conversion ratio compared to the control (2.06) group (P=0.08). Crypt depth of ileum was lower in chicks fed diet with 0.1% betaine (72.40 µm) than the control (85.60 µm) (P