Abstract
A 10 week feeding trial was conducted to investigate the effects of dietary glucose, dextrin and starch on growth and body composition of juvenile starry flounder. Triplicate groups of fish (average weight, 9.7 g) were fed iso-nitrogenous (53% crude protein) and iso-caloric (16.1 kJ/g diet) diets containing 20% glucose, 20% dextrin and 5-25% α-potato starch with 5-14% lipid levels. Survival was not affected by dietary carbohydrate. Weight gain, feed efficiency and protein efficiency ratio of fish fed the diet containing 20% glucose were the lowest among all groups. The best weight gain was observed in fish fed the diets containing 20% dextrin. Growth and feed efficiency were not affected by dietary α-potato starch level. Lipid contents of the whole body and liver were not affected by dietary glucose, dextrin and starch at the same level. However, lipid content tended to decrease with increasing dietary starch level and those of fish fed the diets containing 5% α-potato starch were significantly higher than those of fish receiving 10-25% α-potato starch. Liver glycogen content and hepatosomatic index tended to increase with increasing dietary starch level. These results indicate that juvenile starry flounder are able to efficiently utilize dextrin and α-potato starch compared to glucose in diets and that up to 25% α-potato starch could be incorporated in the diet of juvenile starry flounder for optimum growth.
