Effect of dietary A-Max supplementation as a prebiotic on growth performance and hemato- immunological parameters of great sturgeon (Huso huso Linnaeus, 1758) juveniles

An 8-week feeding trial was conducted to evaluate the effects of dietary commercial prebiotic A-Max, a mixture of mannan oligosaccharides, fructo oligosaccharides and B glucan, on growth and hemato-immunological parameters of great sturgeon (Huso huso) juveniles. After acclimation, fish (initial weight of 28.79±0.85 g) were placed into 12 tanks (30 fish per tank). Fish were fed a basal diet (containing 44% protein and 20% lipid) supplemented with 0 (control), 0.5, 1.0 and 1.5 g kg-1 A-Max in a totally randomized design in triplicate groups. At the end of the trial, growth factors and haemato-immunological parameters were assessed. Fish fed 1.5 g kg-1 prebiotic mixture displayed higher growth performances and feed efficiency compared to the control group (p > 0.05). There were no significant differences in survival rate among all treatment groups (p > 0.05). The results showed that RBC, WBC, lymphocyte, neutrophil, haematocrit and total protein were significantly affected by 1.5 g kg-1 dietary prebiotic mixture (p < 0.05). An elevation of monocyte and haemoglobin (p > 0.05) was found in the fish fed diet containing 1.0 g kg-1 prebiotic. In addition fish fed the diet with 1.5 g kg-1 prebiotic mixture showed a significant increase in lyzosyme activity, respiratory burst activity, serum total immunoglobulin (Ig) and alternative complement activity (ACH50) (p < 0.05) compared with those fed the diets supplemented with other levels of prebiotics. The results showed that the addition of 1.5 g kg-1 prebiotic mixture to the diet of great sturgeon juveniles improving growth performance, some haematological parameters and immune response and seemed to be an effective immunostimulant.