A 10week net pen experiment was carried out to examine the capacity of malabar grouper(Epinephelus malabaricus)in utilizing a blend of poultry byproduct meal,feather meal and blood meal at different dietary protein levels.A 2×4 experimental design,including two dietary protein levels(490 and 530 g/kg crude protein)and four fish meal level(500,350,200,50 g/kg),was established.At each dietary protein level,one feed was formulated to contain 500 g/kg herring meal as control,and in the remaining three feeds,the blend that was formulated to contain 65% poultry by product meal,20% feather meal and 15% blood meal was incorporated at 139,278 or 416 g/kg to replace 30%,60% or 90% of the fish meal.Initial body weight of the experimental fish was(33.4±0.1)g per fish.During the experiment,fish were fed to satiation twice daily except the days during which extremely high temperature or heavy waves occurred.The results of the experiment indicated that dietary protein level did not significantly affect feed intake(FI),weight gain(WG),feed conversion ratio(FCR),nitrogen retention efficiency(NRE),energy retention efficiency(ERE)and whole body composition,while dietary fish meal content had significant effect on WG,FCR,NRE and ERE.At the same dietary protein level,specific growth rate(SGR)decreased with the decrease of fish meal level.At the same dietary fish meal level,fish fed the feeds containing 530 g/kg crude protein had slightly high SGR relative to fish fed the feeds containing 490 g/kg crude protein.Results of the present study reveal fish meal level in diets for malabar grouper can be reduced to 200 g/kg by incorporating the blend of poultry by-product meal,feather meal and blood meal,and no benefit was found in reducing dietary fish meal level for malabar grouper by elevating dietary protein level from 490 to 530 g/kg crude protein.