Effect of different sources of carbohydrate on growth performance, body composition, digestibility, digestive and liver enzymes of Siberian sturgeon (Acipenser baerii)

The present study was carried out to determine the effect of different levels of glucose and corn starch as carbohydrate sources on growth performance, body composition, digestibility, digestive and liver enzymes of Siberian sturgeon (Acipenser baerii). A total number of 120 Siberian sturgeons weighing 25.64 ± 2.80g were fed four diets including glucose 15%, glucose 30%, corn starch 15% and corn starch 30% for a period of 11 weeks. Results showed that final weight, final total length, percentage of body weight increase, specific growth rate, mean daily growth, protein efficiency ratio and condition factor in fish fed corn starch 15% were high in comparison with other treatments (P>0.05). Significant difference was seen between fish fed corn starch 30% with fish fed glucose 15% in hepatosomatic index (P<0.05). The highest content of carcass protein was seen in corn starch 15% that showed significant difference with glucose 15% and 30% (P<0.05). Fish fed glucose 15% had the highest content of carcass total carbohydrate which showed significant difference with corn starch 15% and 30% (P<0.05). The contents of lipase, pepsin, trypsin and chymotrypsin enzymes and also apparent digestibility of protein and lipid in fish fed corn starch 15% were higher than the other treatments (P<0.05). The highest contents of liver enzymes were recorded in fish fed glucose 30% (P>0.05). Based on the mentioned results, corn starch at the level of 15% can increase growth and improve body composition, digestibility and digestive enzymes in Siberian sturgeon.