Effect of dietary carbohydrate sources on the growth performance, feed utilization, muscle composition, postprandial glycemic and glycogen response of Amur sturgeon, Acipenser schrenckii Brandt, 1869

The present study was conducted to compare growth performance, feed utilization, muscle composition, and postprandial glycemic and glycogen responses of juvenile Amur sturgeon, Acipenser schrenckii, fed different carbohydrate diets in order to select the most appropriate carbohydrate sources for this species. Six experimental diets were formulated containing 22% glucose, fructose, maltose, dextrin, -starch or cornstarch, respectively. Triplicate groups of 20 fish (average weight: (4.7 +/- 0.1) g, means +/- SD) were randomly fed one of the six diets for eight weeks. Results showed that the weight gain rate was highest in fish fed the dextrin (716.0%) or -starch diet (782.9%), and lowest in fish fed the fructose diet (333.2%). Specific growth rate and feed efficiency showed a similar weight gain rate pattern. Apparent digestibility of dietary carbohydrate for Amur sturgeon was the fructose, glucose> maltose> dextrin> -starch > cornstarch diet; apparent digestibility of dietary protein was the fructose> glucose, maltose, dextrin> cornstarch> -starch diet. Contents of muscle moisture, ash and crude lipid were significantly affected by the difference in dietary carbohydrate sources (P<0.05), but no significant difference was observed in crude protein content (P>0.05). Dietary carbohydrate sources significantly affected plasma glucose and liver glycogen concentrations in sturgeon in different periods after feeding (P<0.05). According to the weight gain rate, dextrin and -starch were the most appropriate carbohydrate sources for juvenile Amur sturgeon, whereas fructose was deemed to be an inadequate carbohydrate source.