The effects of replacing fish meal protein with a mixture of poultry by‐product meal and fermented soybean meal on the growth performance and tissue nutritional composition of Asian seabass ( Lates calcarifer )

The effects of fish meal (FM) protein replaced with a mixture of poultry by-product meal (PBM) and fermented soybean meal (FSBM) on the growth performance of Asian seabass (Lates calcarifer) was investigated. Seven diets were formulated to replace 0% (CON−), 0% (CON+), 20% (MPS20), 40% (MPS40), 60% (MPS60), 80% (MPS80) and 100% (MPS100) FM protein with a mixture of 60% PBM and 40% FSBM. Treatment diets except CON− contained feed attractants; each diet was randomly assigned to triplicate groups of ten 1.27 g fish for 6 weeks. The fish fed the CON−, CON+, MPS20, MPS40 and MPS60 diets showed no significant differences in weight gain percentage (WG%) and specific growth rate (SGR), whereas those fed the MPS100 diet had the lowest WG% and SGR. The crude lipid of fish muscle ranged from 66 to 71 g/kg, whereas that of fish liver ranged from 372 to 426 g/kg. The amounts of polyunsaturated fatty acid (PUFA) and n-3 LC-PUFA of fish muscle decreased as the FM protein replacement level increased. A mixture of 60% PBM and 40% FSBM would be able to substitute FM protein for up to 60% without adverse effects on the growth performance of Asian seabass.