Effect of dietary protein/starch ratio and energy level on growth of the giant freshwater prawn Macrobrachium rosenbergii

Feeding experiments were carried out with the giant freshwater prawn Macrobrachium rosen-bergii juveniles in order to determine the requirement of dietary protein and energy levels in terms of growth, feed efficiency, and body constituents. Protein requirement was between 13-25%. Namely, the highest survival and growth occurred in the group fed with the protein/starch (P/S) ratio of 1: 1, although feed efficiency was the highest at the P/S ratio of 1:3. The effect of dietary energy level were studied in purified diets with constant P/S ratio (1:1). Increasing the dietary energy level improved growth and feed efficiency. However, protein efficiency ratio was maximal in the diet with 384kcal/100 g. High cellulose in the diet seemed to induce not only retardation of growth, but also depression of locomotive activity. With regard to muscle constituents, a definite variation was found in lipid, in response to dietary composition. Triglycerides were not found, while mono-, diglycerides, and phospholipids re-presented about 90% in the muscle lipid. The lipid level and lipid class composition seemed to be related to the nutritional condition.