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.

Automated summary

The study found that replacing fish meal protein with a mixture of 60% poultry by-product meal and 40% fermented soybean meal can substitute up to 60% of the feed protein without adverse effects on the growth performance of Asian seabass. The different replacements of fish meal protein had varying effects on the weight gain percentage and specific growth rate of the seabass.