Feeding strategy does affect carbohydrate utilization by hybrid tilapia Oreochromis niloticus × O. aureus

Abstract

An eight-week growth trial was conducted to evaluate the effect of feeding strategy (continuous fed vs two meals per day) on the utilization of carbohydrate by juvenile hybrid tilapia, Oreochromis niloticus × O. aureus. The carbohydrates were starch and glucose, and included at 44% of the diet. Average initial body weight of the fish was 0.47 ± 0.01 g, and fish were fed at a rate of 5% body weight per day. The results indicated that weight gain was significantly higher (p<0.05) for fish fed continuously than for those fed two meals a day for both carbohydrate diets. Higher hepatic phosphofructokinase (PFK) and malic enzyme (ME) activities were observed in the continuous-fed fish than in meal-fed fish. Hepatic asparate transaminase (AST) and alanine transaminase (ALT) activities of the continuous-fed fish with glucose diet were lower than those of the meal-fed fish. Plasma AST and ALT activities were higher in the meal-fed fish than in the continuous-fed fish. These data suggest that carbohydrate utilization by tilapia is affected by feeding strategy and that continuous fed improves carbohydrate utilization.