Lecithin requirement of Penaeus monodon juveniles

Abstract

An 8-week feeding experiment was carried out to determine the lecithin requirement of Penaeus monodon postlarvae. Six shrimps with initial mean weight of 0.11 g were stocked in oval fiberglass tanks in a flowthrough system with 40 ℓ of seawater. There were 5 replicates or a total of 30 shrimps per treatment. Diets were similar for all treatments except for the source of lipid and levels (0, 1 and 2%) of added soybean lecithin. Cod liver oil (treatments 1 to 3), crude degummed soybean oil (treatments 4 to 6) and refined soybean oil (treatments 7 to 9) were the three sources of lipid.

Differences in mean weight gain due to source among treatments were not significant after the fourth week of feeding but were significant after the sixth week. Mean survival rate was affected by source of lipid after the fourth and sixth weeks. Levels of lecithin significantly affected mean weight gain after the fourth and sixth week of feeding. Mean survival rate was significantly different among treatments after the sixth but not the fourth week. Although feed conversion or feed efficiency was generally poor, a trend is discerned. Feed conversion improved as dietary levels of lecithin increased from 0 to 2%. P. monodon juveniles need lecithin but the amount has yet to be defined.