The Effect Of Different Carbohydrate Sources In Diet On Aquaculture Performance And Mechanism In GIFT Nile Tilapia(Oreochromis Niloticus) Juvenile

The effect of practical diet’s carbohydrate sources on aquaculture performance, blood parameters and activities of four carbohydrate metabolic enzymes in Genetic Improvement of Farmed Tilapia strain Nile tilapia (Oreochromis niloticus)(GIFT strain Nile tilapia) were studied in this paper. Six kinds of isonitrogenous (35.43%) and isoenergetic (15.95KJ/g) semi-pure formulated diets were designed in which contained25%glucose, maltose, sucrose, sugarcane molasses, dextrin and wheat starch as experiment groups1,2,3,4,5and6respectively. Each diet was fed for61days to triplicate nets of20fish (3.4±0.2g; mean±SE), random arranged in nets of an indoor cement pit with circulation system.The result showed:the specific growth rate (SGR) and feed efficiency ratio (FER) in groups1and2were significantly lower than other groups (p<0.05). Group1had lower parameters, such as carcass protein, glucose, cholesterol, triglyceride, and significantly lower indexes than other groups on carcass lipid, gross energy, muscle glycogen and total protein (p<0.05). The carcass protein, carcass lipid, gross energy, glucose and cholesterol were lower in group2. For liver lipid, both of groups1and2showed significantly lower than other groups (p<0.05). Apart from the pyruvate kinase (PK) activities in hepatic tissue demonstrated no significant difference between groups (p>0.05), significantly higher hexokinase (HK) activities in hepatic tissue were observed in groups1and2(p<0.05). Besides, the glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities of hepatic tissue in groups1and2showed significantly lower than other groups (p<0.05).So we summarize that the differences on aquaculture performance of juvenile GIFT strain Nile tilapia by feeding distinct sugar substructure diets were related with hexokinase (HK) activities,glucose-6-phosphatase(G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities in hepatic tissue, rather than the molecular size of carbohydrates.It’s safe and practical to largely add sugarcane molasses in feed of juvenile GIFT strain Nile tilapia, which can improve the economic benefit and value of sugarcane molasses, as well as saving grain resources.