Singular or combined dietary administration of multi-strain probiotics and multi-enzyme influences growth, body composition, digestive enzyme activity, and intestinal morphology in Siberian sturgeon (Acipenser baerii)

The effectiveness of single versus combined dietary supplementation of multi-strain probiotics and exogenous multi-enzyme (Ronozyme(R)) on growth indices, feed utilization and gastrointestinal functions of Siberian sturgeon was investigated for 10 weeks. A feeding trial was performed in triplicate with the juveniles (N = 240; 138.1 g), which were fed on C: basal diet (control), E: 62.5 mg/kg Ronozyme(R) (25 mg/kg xylanase, 30 mg/kg protease and 7.5 mg/kg phytase), P: 2 g/kg probiotics mixture (Pediococcus pentosaceus 1 x 10(9) and Lactococcus lactis 1 x 108 CFU/g) and P + E diets. Upon the completion of the feeding trial, the group fed with dietary P + E showed the highest final body weight and metabolic weight gain; however, the lowest feed conversion ratio was calculated in E and P + E groups (p < 0.05). Protein and lipid efficiency ratios were significantly decreased in the control group (p < 0.05). The highest and lowest crude protein and lipid contents were recorded in P + E treatment, respectively (p < 0.05). The height, width and area of intestinal villi in the fish fed with treated diets were higher than the control group (p < 0.05). The activities of lipase and protease were increased in P and P + E groups (p < 0.05). The load of lactic acid bacteria was upregulated in the fish gut fed with P and P + E diets (p < 0.05). Overall, the combination of the probiotics mixture and multi-enzyme significantly improved the metabolism and digestibility of Siberian sturgeon.