Eman A Abd El-Gawad *,Ashraf M Abd El-latif ,Ramy M Shourbela
In this study, Nile tilapia was fed experimental diets containing different levels (0, 1, 2, and 3%) of fructooligosaccharide (FOS) for 6 weeks to investigate its effect on the antioxidant activity, non-specific immunity and growth performance of Nile tilapia. Liver and serum samples were taken after 3 and 6 weeks feeding. Results showed that malondialdehyde level and superoxide dismutase activity decreased significantly (P<0.05) with dietary FOS supplementation after 3 and 6 weeks feeding compared to the control. Catalase and glutathione peroxidase activities were significantly decreased in groups fed 1 and 2% FOS for 3 weeks. Serum immunoglobulin M and lysozyme activity were significantly increased with dietary FOS after 3 and 6 weeks feeding. Nitric oxide revealed significant increase with 2% dietary FOS after 3 weeks feeding and there were no significant difference (P>0.05) in other treated groups fed for 6 weeks compared to the control. Weight gain also recorded significant increase in group fed 2% FOS for 6 weeks. These results indicated that dietary FOS supplementation could significantly enhance the antioxidant activities, non-specific immune response and growth performance of Oreochromis niloticus. It could be conclude that 2% dietary FOS was the most suitable and beneficial dose for Nile tilapia.