Bed sea bream Pagrus major having a mean body weight of 18.5 g were reared
on diets containing 0, 10, 20, and 30% of rapeseed protein concentrate (RPC
) for 52 days. Glucosinolates, sinapine, and phytic acid contents of RPC we
re respectively 0.58 mu mol/g, 0.2%, and 4.4%. Final mean body weights of f
ish fed the 20 and 30% RPC diets were lower than fish fed the 0 and 10% RPC
diets. No significant differences among the dietary treatments were found
in daily feed intake, feed efficiency, protein efficiency ratio, hematology
, and relative weight of the hepatopancreas, stomach and intestine to body
weight, Crude fat content of the whole body fell, but that of the hepatopan
creas increased with an increase in diet RPC levels. Hematological characte
r and plasma total protein, albumin, cholesterol, Mg and Zn concentrations
did not show any differences among the dietary treatments. However, plasma
P concentrations of fish fed the 0 and 10% RPC diets were higher than fish
fed the 30% RPC diet. Moreover, apparent protein and sugar digestibilities
fell slightly with an increase in dietary RPC contents. These results sugge
st that a practically substituitve limit with RPC for dietary brown fish me
al is about 10% in red sea bream.