Substitution of fish meal by Jatropha curcas kernel meal: Effects on growth performance and body composition of white leg shrimp (Litopenaeus vannamei)

Jatropha curcas (L.) is a multipurpose and drought-resistant tree, widespread throughout the tropics and subtropics. Its seeds are rich in oil and protein (contains 600-660 g kg(-1) crude protein similar to fish meal). It is being promoted as a biofuel plant. Jatropha kernel meal obtained after oil extraction is an excellent source of protein. However, presence of toxic and antinutritional constituents restricts its use in fish and shrimp feed. An 8-week experiment was conducted to evaluate the nutritional quality of the detoxified Jatropha kernel meal (DJKM) in white leg shrimp (Litopenaeus vannamei). Shrimp (60) with an initial average body weight of 4.46 +/- 0.64 g were randomly distributed into three treatments with four replicates and fed isonitrogenous and isoenergetic diets (crude protein 350 g kg(-1), crude lipid 90 g kg(-1)): Control (fish meal-based protein), JC(25) and JC(50) (25% and 50% of fish meal protein replaced by DJKM). Higher (P < 0.05) body mass gain, specific growth rate and metabolic growth rate were observed in DJKM-fed groups than in Control group. However, lower (P > 0.05) feed conversion ratio was observed in DJKM-fed groups, while protein efficiency ratio exhibited an opposite trend. Protein, ash and gross energy content of the whole shrimp body were higher (P < 0.05) in DJKM-fed groups compared to Control group. Moisture and lipid content of the whole shrimp body did not differ significantly among the three groups. Cholesterol level in plasma was highest (P < 0.05) in the Control group, followed by JC(25) and JC(50) groups; all being significantly different. In conclusion, DJKM is a promising fish meal replacer in shrimp diets.