Effects of the prebiotics Immunoster and Immunowall on growth performance of juvenile beluga (Huso huso)

Abstract

Summary The objective of this study was to determine the effects of the prebiotics Immunoster and Immunowall (two commercial prebiotics) on growth performance of juvenile beluga (Huso huso). Prior to the feeding trials, fish were fed the basal diet to apparent satiation four times per day for a 4-week acclimatization period. The basal diet contained 42% crude protein, 14.5% crude lipid, 10.06% ash and 6.1% moisture. Then, 450 beluga juveniles weighing 95.6 ± 9.4 g were randomly distributed into 15 fiberglass tanks (2 · 2 · 0.53 m) in three replicates and kept at a density of 30 fish per tank. Two levels (1 and 3%) of Immunoster and two levels (1 and 3%) of Immunowall were added to the basal diet in place of cellulose. Diets were manufactured by extrusion processing. Juvenile belugas were fed four times daily at rates approximately apparent to satiation for 8 weeks. Average Daily Growth (ADG), Body Weight Gain (BWG), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Condition Factor (CF) and Hepatosomatic Index (HSI) were monitored and assessed. Generally, fish fed Immunoster and Immunowall had better growth characteristics during the 8-week feeding trial. Survival rate was 100% in all treatments. Final weight and final length were significantly affected by Immunoster and Immunowall (at both levels) in all experimental groups in comparison with the control group (P < 0.05). The highest and the lowest final weight were observed in Immunowall 1% (241.6 ± 85 g) and control (199.2 ± 84.7 g), respectively. It can be declared that two mentioned prebiotics can improve growth performance of beluga sturgeon.