Cholesterol requirement of subadult black tiger shrimp Penaeus monodon (Fabricius)

The high cost of cholesterol used in aquaculture diets for shrimp makes it important to precisely define their requirement for this essential nutrient in order to avoid excess supplementation of the diet. Two experiments were carried out to determine the cholesterol requirement of subadult (about 3 g) Penaeus monodon (Fabricius). The growth response and survival of shrimp were compared following feeding for up to 8 weeks with diets in which the cholesterol content varied between 0.7 and 8.5 g kg(-1). Feed intake was quantified and the retention of ingested cholesterol determined by whole body analysis. The cholesterol requirement of subadult P. monodon was found to be about 75 mg kg(-1) body weight d(-1). The optimum dietary cholesterol content was approximately 1.7 g kg(-1) (dry matter), which is appreciably lower than the current recommendation of 2.3-4 g kg(-1). In most practical shrimp diets, the endogenous cholesterol in the ingredients provides more than 1.7 g kg(-1) of cholesterol. Hence, our research suggests that it may be unnecessary to add expensive, supplementary cholesterol to commercial shrimp diets.