Potential of Several Protein Sources as Fish Meal Substitutes in Diets for Large Yellow Croaker, Pseudosciaena crocea R

A feeding experiment was conducted to evaluate the potential of replacing fish meal (FM, Diet 1) with soybean meal (SBM, Diet 2), meat and bone meal (MBM, Diet 3), poultry by-product meal (PBM, Diet 4), and peanut meal (PM, Diet 5) in practical diets of juvenile large yellow croaker, Pseudosciaena crocea. Five isonitrogenous and isoenergetic diets (43% crude protein and 20 kJ/g gross energy on dry matter basis) were formulated. Diet containing FM as the main protein source was used as a control (Diet 1). Diets 2-5 had 30% of the FM protein replaced with SBM, MBM, PBM, or PM protein. Each diet was randomly assigned to triplicate groups of 25 fish per cage (initial body weight 23.3 ± 0.96 g). Fish were maintained in sea floating cages (1.5 × 1.5 × 2.0 m), water temperature ranged from 27 to 30 C, salinity from 25 to 28‰ and dissolved oxygen content was more than 7 mg/L. Fish were hand-fed twice daily to apparently satiation for 8 wk. Fish fed Diets 1-4 showed no significant difference in survival, weight gain (WG) and specific growth rate (SGR), while fish fed Diet 5 showed significant inferior WG and SGR (P < 0.01). Carcass crude protein and crude lipid of the fish fed Diet 5 were significantly lower than those of the fish fed the other diets (P < 0.05). Carcass lysine content of the of fish fed Diet 5 showed slight, yet significantly decrease (P < 0.05), compared with those of the fish fed Diets 1-4, while other essential amino acids (EAAs) content showed no significant differences among the different treatments. Results of the present study indicate that about 30% of FM protein can be replaced by SBM, MBM, or PBM protein in large yellow croaker diets without adversely effecting growth.