Dried porcine soluble benefits to increase fish meal replacement with soy protein concentrate in large yellow croaker Larimichthys crocea diet

Abstract

AbstractThe effect of dried porcine soluble (DPS) supplementation on replacement of dietary fish meal with soy protein concentrate (SPC) for large yellow croaker, Larimichthys crocea, was assessed in a feeding trial conducted in inshore net pens. Five isoproteic and isolipidic diets were tested. A basal diet (BD) contained 400 g/kg fish meal, and SPC was used as an alternative ingredient to replace 40% (F24) and 60% (F16) of the fish meal in BD at an equal protein basis. DPS was added at 5 g/kg in F24 (FD24) and F16 (FD16). Fish weighing 33.6 ± 7.4 g were fed with the test diets in 1.5 × 1.5 × 2 m net pens for 9 weeks. The fish meal replacement level significantly affected weight gain, feed conversion ratio, phosphorus retention efficiency, body phosphorus content, and ratio of fish meal consumption to fish production (RCP), while the DPS supplementation level significantly affected weight gain. The weight gain of fish fed FD24 was higher than that of fish fed F16, while no significant difference was found in weight gain between fish fed BD and fish fed FD24, F24, FD16 and F16. The feed cost, RCP and phosphorus waste of fish fed BD were higher than those of fish fed FD24, F24, FD16 and F16. Fish fed FD24 exhibited the best production performance, and the production performance of fish fed F24 and FD16 was close to that of fish fed BD. The present study indicates that the fish meal level in large yellow croaker diet could be lowered to 240 g/kg with SPC alone as a fish meal substitute, and could be further reduced to 160 g/kg by supplementation of 5 g/kg DPS. Therefore, DPS supplementation can benefit to increase fish meal replacement with SPC in large yellow croaker diet.