Effect of dietary protein and lipid levels on growth performances and digestive enzymes activities in grouper (Epinephelus coioides)

Abstract

This study investigates the effect of dietary protein and lipid levels on growth and digestive enzymes activities in grouper (Epinephelus coioides). Furthermore, grouper juveniles (8.63±0.47 g) were separated into ten groups and cultivated in a 100-L tank. Five groups were fed in different protein levels of 35, 40, 45, 50, and 55% protein, while the remaining were fed in different lipid levels of 6, 8, 10, 12, and 14% lipid. All experimental diets were mixed with 1.0% Sauropus androgynus extract. The fishes were sampled for digestive enzyme activities at 1, 4, and 7 days. The results showed that fish receiving 55% protein affected the growth and increased the activities of protease, lipase, carboxypeptidase A (CPA), and carboxypeptidase B (CPB). Liver tissue included higher levels of lipase, as well as carboxypeptidase A and B, while digestive tract tissue contained measurable levels of protease. In conclusion, the administration of grouper juveniles with S. androgynus extract can affect growth performances and increase digestive enzyme activities.