Effect of Different Carbohydrate Sources on the Growth,Body Composition, Plasma Biochemical Indices and Glycolytic Enzyme Activities of Trachinotus ovatus

Abstract:

In this trial, five isonitrogenous and isolipidic diets were formulated with different carbohydrate sources at 20%, including glucose, sucrose, dextrin, corn starch, and gelatinized corn starch. The Trachinotus ovatus with initial weight of (31.24±0.58) g were fed with each diet for 8 weeks. Then the effects of different carbohydrate sources on a variety of biological activities were compared so to determine the optimal carbohydrate sources. The results suggested that the carbohydrate sources with higher molecular weight significantly increased the weight gain (WG) and the specific growth rate (SGR) (P<0.05). The group fed with gelatinized corn starch showed the highest WG (335.35%) and SGR (2.62%/d). The vicerosomatic index (VSI), hepatosomatic index (HSI), liver glycogen content, and muscle glycogen content of the five carbohydrate groups were significantly different (P<0.05), and those of the glucose group were the highest. Carbohydrate sources also affected the levels of plasma glucose, total cholesterol, and triglycercide (P<0.05). No significant difference was observed in hepatic hexokinase (HK) activity (P>0.05). Activities of glucokinase (GK), pyruvate kinase (PK) and phosphofructokinase (PFK) reached the highest in the glucose group (P<0.05). These results suggested that macromolecules (starch) are better for the growth of T. ovatus than glucose, sucrose, and dextrin, thus gelatinized corn starch should be the optimal carbohydrate source. Furthermore, carbohydrate sources may also have effects on the glycogen synthesis, glycolipid transformation and glycolysis.