The biochemical,pathological and immunological effectiveness of commercial probiotics in nile tilapia,oreochromis niloticus

Improved resistance against diseases in nile tilapia,oreochromis niloticus can be achieved by probiotics. a total of 450 fish (50±5 g) were divided into 5 groups: 1st group received diet with 0.1 ml/kg c.a growth® probiotic,2nd group received diet with 0.2 ml/kg feed c.a growth® probiotic,3rd group received diet with 0.15 g/kg feed tonolest® probiotic,4th group received diet with 0.3 g/kg feed tonolest® probiotic,5th group was fed on probiotic-free diet. eight weeks later,fish fed c.a growth® probiotic revealed significant increase in phagocytic activity,differential leucocytic count,serum lysozyme and bactericidal activity,total protein and globulin levels than fish fed on tonolest® probiotic. moreover,groups receiving c.a growth® probiotic showed significant increase in antibody titre against aeromonas hydrophila than other groups. in addition,nile tilapia receiving c.a growth® probiotic showed significant decrease in cortisol hormone and bacterial counts in gastrointestinal tract than fish receiving tonolest® probiotic in all weeks. c.a growth® probiotic evoked no/limited cellular damage and decreased pathological lesions in groups challenged with a. hydrophila. on the other hand,tonolest® probiotic evoked more pathological damage in organs especially with high dose and less effective in decreasing pathological changes in groups challenged with a. hydrophila. © copyright 2016 zoological society of pakistan.