Effects of meal frequency on growth performance of hybrid tilapia, Oreochromis niloticus × O. aureus, fed different carbohydrate diets

To investigate the effect of meal frequency on the utilization of carbohydrate by tilapia, Oreochromis niloticus × O. aureus, diets containing 44% of different carbohydrates were fed for 8 weeks either two or six times a day. The three carbohydrates were starch, dextrin and glucose. Each diet was fed to three aquaria of fish with 15 fish/aquarium. The results indicated that weight gain was significantly higher (P < 0.05) for fish fed six times a day than for those fed two times a day for all three carbohydrate-containing diets. Feed efficiency ratio, protein deposited and energy retained generally followed the same patterns as the weight gain. Fish receiving the glucose diet grew significantly (P < 0.05) slower (225.15% weight gain) than fish receiving the dextrin (262.39% weight gain) or starch (246.29% weight gain) diet when fed two times a day. Phosphofructokinase (PFK) and 6-phosphogluconate dehydrogenase (6PGD) activities were higher in fish fed six times a day.