This study aims to evaluate the effects of prebiotics (inulin and fructooligosaccharides (FOS)) on the growth performance and immune response of stripped catfish fingerling (Pangasianodon hypophthalmus). Experiment was randomly designed with 5 treatments including control; 0.5% inulin; 1% inulin; 0.5% FOS and 1% FOS, triplications for each treatment. The experiment was carried out for 28 days. After 21 and 28 days, several immune parameters including the total erythrocyte cells, total leucocyte cells, number of each type of leucocytes and lysozyme activity were analyzed for evaluation of fish immune response. After 28 days, fish was weighted for estimation of growth performance and challenged with Edwardsiella ictaluri for evaluation of bacterial resistance. Fish mortality was recorded every day for 14 days. After 3 days of infection with E. ictaluri, 3 fish/tank were collected for immune assay. Results showed that hematological parameters and lysozyme activity of inulin and FOS supplemented treatments were higher than those of control treatment after 28 days. Treatment of 1% inulin showed that the total number of leukocyte, monocyte, neutrophil, lymphocyte, thrombocyte and lysozyme activity were higher than those of control treatment after 28 days. The lowest mortality after challenge with E. ictaluri was also addressed in treatment 1% inulin and the difference was statistically significant compared to the control treatment (p<0.05). Base on these results, supplemetation of 1% inulin enhanced immune response of striped catfish and could protect the fish from bacterial damage.
Key word: FOS, growth performance, inulin, immunostimulants, Pangasianodon hypophthalmus.