Research On Animal Production

The experiment was conducted to evaluate the effect of antibiotic, organic acid, probiotic and prebiotic on performance and small intestinal morphology in male Ross 308 broiler chicks for 42 days in tropical conditions. The study was completely randomized design with 5 treatments, 4 replicates and 8 chicks per each. The treatments were: T₁: basal diet, T₂: diet containing antibiotic oxytetracycline (150 g/ton of feed), T₃: diet containing organic acid orgacid (3 kg/ton of feed), T₄: diet containing probiotic protoxin (150 g/ton of feed) and T₅: diet containing prebiotic mannan oligosaccharide (2 kg/ton of feed). The results showed that the experimental diets had no significant effect on feed consumption, live weight and feed conversion ratio. The relative length of jejunum and ileum by prebiotic significantly increased (P<0.05). The acidity of different parts of the small intestine, showed significantly decreased by consumption of organic acid supplementation (P<0.05). The treatment receiving probiotic significantly increased the height of the villi in duodenum and jejunum (P<0.05). Also treatment receiving antibiotic and probiotic significantly increased villi height to crypt depth ratio in the jejunum (P<0.05). The thickness of the muscle layer in jejunum and ileum by consumption of organic acid and probiotic significantly decreased (P<0.05). Generally, the results of the present study showed the positive effects of supplements used on the morphological characteristics of small intestine, but did not have any difference in the performance of broiler chickens.