LAUSR

The dietary supplementation of acidifier in Cirrhinus mrigala juvenile was evaluated in terms of change in growth, autochthonous intestinal microbiota and haemato-biochemical parameters for period of 60 days. Acidifier was added at a level of 0 (control diet), 0.5, 1 and 1.5% to the practical pellet diet. At the end of the experiment, growth parameters, survival, bacillus bacterial population, haematological and immunological parameters were analysed. Higher WG%, SGR and PER and lower FCR (P < 0.05) was found in group fed 1.5% OA. Lysozyme activity and respiratory burst activity (nitroblue tetrazolium) were significantly affected by dietary 1.5% acidifier (P < 0.05). In fish fed on the diet with 1.5% acidifier showed a significant increase of total heterotrophic autochthonous bacterial and Bacillus levels (P < 0.05) compared with those fed on the diets supplemented with organic acid. In addition to increase in WBC, RBC, haemoglobin and platelets count levels were observed in this group. Relative % survival rate was found to be higher in the fish fed on 1.5% acidifier after challenging with Aeromonas hydrophilla bacteria. These results indicated that dietary supplementation of acidifier at a dose of 1.5% improved growth performance and enhanced the beneficial intestinal microbiota and stimulate immune response of Cirrhinus mrigala juvenile.