Dietary myo-inositol requirements of juvenile hybrid sturgeon (Acipenser baerii ♀ x A. schrenckii ♂)

This study was conducted to determine the optimal dietary myo-inositol (MI) requirement of juvenile hybrid sturgeon (Acipenser baerii female x A. schrenckii male). Fish with an initial average body weight of 28.28 +/- 0.41 g were randomly divided into six groups with three repetitions in each group and fed the experimental diets with different graded MI concentrations (70.2, 130.0, 270.2, 443.0, 1,096.6 and 1997.3 mg/kg) three times per day for 12 weeks. The results showed that with the increase in dietary MI level from 70.2 mg/kg to 443.0 mg/kg, weight gain (WG) was increased significantly (p < .05); however, when the MI level was further increased, there was no significant difference in weight gain rate (WG) over time (p > .05). Specific growth rate (SGR) showed a similar trend. The feed conversion ratio (FCR), survival rate (SR), hepatosomatic index (HSI), viscerasomatic index (VSI) and condition factor (CF) were not affected by dietary MI supplementation (p > .05). Dietary MI did not affect whole-body and muscle crude protein and ash content (p > .05), while dietary MI significantly affected the muscle and whole-body crude lipid and moisture content (p < .05). Moreover, serum triglyceride (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were decreased by increasing dietary MI levels. Total antioxidant capacity (T-AOC), malonic dialdehyde (MDA) and superoxide dismutase (SOD) activities in the liver were also affected by the dietary MI (p < .05). In summary, this study indicated that the optimal dietary MI requirement for juvenile hybrid sturgeon (Acipenser baerii female x A. schrenckii male) was 335.84 mg/kg and 590.65 mg/kg based on the maximum WG and liver MI accumulation indices respectively.