Effect of Magnifera indica kernel as a feed additive on immunity and resistance to Aeromonas hydrophila in Labeo rohita fingerlings

The study evaluated the efficacy of dietary doses of Magnifera indica (mango) kernel on the immune response and disease resistance of Labeo rohita fingerlings against the bacterial pathogen Aeromonas hydrophila infections in. L. rohita fingerlings fed diet containing 0 (Control), I g, 5 g, 10 g mango kernel kg(-1) dry diet for 60 days. Biochemical (serum total protein, albumin, globulin, albumin:globulin ratio, blood glucose), haematological (WBC, RBC, haemoglobin content) and immunological (superoxide anion production, lysozyme, serum bactericidal activity) parameters of fish were examined at 20, 40 and 60 days of feeding. Fish were challenged with A. hydrophila 60 days post feeding and mortalities were recorded over 10 days post-infection. The results demonstrate that fish fed with mango kernel showed enhanced superoxide anion production, lysozyme, serum bactericidal, serum protein, albumin (P < 0.05) compared with the control group. The mortality (%) was recorded up to 10th day post-challenge. Less survivability was observed in control group (50%) up to day 10 after infection. The survivability was higher in experimental diets. The group fed 5 g kernel kg-1 dry diet showed highest percentage survival (98%). These results indicate that mango kernel stimulates the immunity and makes L. rohita more resistant to A. hydrophila infection. (c) 2006 Elsevier Ltd. All rights reserved.