An 8-week Soy Protein for Turtles experiment was conducted to evaluate the effects of dietary fish meal (FM) replaced by soybean protein concentrate (SPC) on Japanese strain of soft-shelled turtle, Pelodiscus sinensis juveniles. Diets were formulated to replace FM protein by SPC at 0, 15, 30, 45, 60 or 60% supplemented with phytase (2000 FTU/kg) and each diet was fed to triplicate groups.

The results showed that SPC could successfully substitute for 30% FM protein in the diets for P. sinensis juveniles, and the maximum effective substitution may be greater if exogenous phytase was added. The turtles fed the 15 or 30% replacement diets showed comparable feed and protein utilization efficiency compared with the control group, whereas more than 30% replacement of FM adversely significantly lowered the apparent digestibility coefficients for dry matter, protein, lipid, phosphorus and gross energy.