Cholesterol and lecithin requirement of juvenile banana shrimp, Penaeus merguiensis

Abstract

Two feeding experiments with three test diets each, were conducted to determine the nutritive values of cholesterol and lecithin for juvenile banana shrimp, Penaeus merguiensis. Artificial diets were prepared by supplementing 0, 0.5 and 1% cholesterol and 0, 1 and 2% lecithin in each diet. All fat-containing ingredients were defatted before use. Results from the cholesterol feeding experiment showed that shrimp fed the diet without cholesterol supplement had similar weight gain to shrimp fed a diet supplemented with 0.5 or 1% cholesterol. This indicates that the noncholesterol supplemented diet which already contained 0.6% sterol esters, might have satisfied the cholesterol requirement of banana shrimp. On the other hand, the excess cholesterol might have caused some adverse effect. The accumulation of nonpolar lipid (NL) in the whole body of shrimp was related to the cholesterol level in the diet. The whole body NL was 31.07, 37.83 and 38.88% in shrimp fed 0, 0.5 and 1% dietary cholesterol, respectively. Body weight gain of shrimp fed 2% dietary lecithin was significantly higher than those fed on a diet without lecithin supplement ( P<0.05). Consequently, the increase in polar lipid content in the whole body of shrimp was found to increase due to phosphatidylcholine (PC) in the diet. The PL content was 59.14, 63.97 and 64.3% for shrimp fed diet supplemented with 0, 1 and 2% lecithin, respectively. There was no difference in total lipid content among treatments and between experimental sets. It varied from 1.94 to 2.13% and 2.04 to 2.13% for the lecithin and cholesterol feeding experiments, respectively. The results of this study suggest that banana shrimp may require lecithin between 1 to 2% in the diet for good growth, high survival and feed efficiency. Whereas, there is no advantage given by supplementing cholesterol to the basal diet.