Reevaluation of Optimum Dietary Protein Level in Juvenile Whiteleg Shrimp, Litopenaeus vannamei (Boone, 1931)

Abstract

This feeding trial was conducted to reevaluate the optimum dietary protein level required for juvenile whiteleg shrimp, Litopenaeus vannamei (Boone, 1931). Triplicate of thirty shrimp averaging 1.0±0.1g (mean±SD) were randomly distributed into each of four diets in 12 plastic aquaria. Shrimps were fed one of four isocaloric diets, containing 33, 38, 44 and 54% crude protein (CP) (CP33, CP38, CP44 and CP54, respectively) at a ratio of 4% body weight per day for six weeks. At the end of feeding trial, weight gain and specific growth rate of shrimp fed CP44 and CP54 diets were significantly higher than those of shrimp fed CP33 diet (P<0.05). Feed conversion ratio of shrimp fed CP44 diet was significantly lower than that of shrimp fed CP33 diet. Protein efficiency ratio was significantly affected by dietary protein level. Dietary protein levels significantly influenced on amino acid composition of edible portion of shrimp. Broken line analysis of weight gain showed an optimum protein requirement of 43.3% in juvenile whiteleg shrimp. Therefore, these results suggest that the optimum dietary protein level could be higher than 43.3% but less than 44% reared in the semi-recirculation system.