Substitute of soy protein concentrate for fish meal in diets of white shrimp (Litopenaeus vannamei Boone)

The present study was conducted to evaluate the effects of partially replacing dietary fish meal (FM) with soy protein concentrate (SPC) on growth, body composition, digestive enzyme activities, and nutrient digestibility of white shrimp. Five isonitrogenous diets with SPC inclusion levels of 0.0, 2.5, 5.0, 7.5 and 10.0%, were prepared to replace 0.0, 12.5, 25.0, 37.5, and 50.0% FM in basal diet containing 20.0% FM, respectively, and fed to white shrimp with an initial body weight of 1.80 g. After 49 days feeding, 5.0% SPC diet did not affect the growth of white shrimp (P > 0.05), but weight gain was decreased (P < 0.05) and the apparent digestibility of dry matter and protein and hepatopancreas protease activity were decreased (P < 0.05) by the inclusion of 7.5% or 10.0% SPC. With the increase of dietary SPC level, the whole-body crude protein content, serum triglycerides, and cholesterol contents decreased (P < 0.05), while the whole-body lipid content increased (P < 0.05). Muscle amino acids showed no significant differences (P > 0.05) among treatments except glycine (Gly). The above results indicated that 25% FM could be substituted by SPC, and the SPC inclusion level was 5% without negative effects on the growth of white shrimp.