the combined effects of the yeast saccharomyces cerevisiae and aspergillus niger on the haematological and biochemical parameters of cultured juvenile beluga (huso huso)

background: probiotics, in form of microbial supplements, are known to be a suitable alternative for antibiotics and can affect the health indicators of host. objectives: the present study was conducted to assess the combined effects of dietary autochthonous saccharomyces cerevisiae and aspergillus niger on haematological and serumbiochemicalparameters of beluga sturgeon (huso huso) juveniles. methods: this study was based on a completely randomized design with 4 treatments and 3 replicates on beluga juveniles with average weight of (mean ±se) 31.8±2.81g. beluga juveniles were divided randomly into 12 fiber glassy tanks with density of 30 fish per tank and were fed with diet contain dietary probiotic with density of 2×106 (cells/g) for the first treatment, 4×106 (cells/g) for the second treatment, 6×106 (cells/g) for the third treatment and basal diet without probiotic for the control group for 8 weeks. results: diet supplementing with concentration of 6×106 (cells/g), significantly improved serum biochemical parameters (p0.05). also results indicate that growth factors were improved in experimental treatments in comparison with the control group. conclusions: the results showed that the use of combination of these species with studied concentrations can improve the performance of some biochemical parameters such metabolites factors, immune, enzymes and serum electrolytes of belugajuveniles. it is recommended that the concentration of a. niger and s. cerevisiae, used for third treatment be used as an immune stimulator for beluga juveniles.