Effects of high levels of n-3
HUFA in broodstock diet on egg quality and egg fatty acid composition of
Japanese flounder, Paralichthys olivaceus
H. Furuita, H. Tanaka, T. Yamamoto, N. Suzuki, T.
Takeuchi-2002
Aquaculture, 210(1-4): 323-333
Abstract:
We investigated the effect of high levels of n-3
highly unsaturated fatty acids (n-3 HUFA) in broodstock diet on egg
quality and chemical composition of eggs of Japanese flounder. The
broodstock were fed diets containing three levels of n-3 HUFA (2.1%,
4.8% or 6.2%) 2 months before and during the spawning period. No significant
difference was found for weight gain of broodstock among the treatments. Egg
production was highest in fish fed the highest level of n-3 HUFA.
However, egg quality parameters, such as percentage of buoyant eggs,
hatching rate and percentage of normal larvae, were significantly higher in
the group fed the lowest n-3 HUFA diet. The fatty acid composition of
eggs was influenced more markedly in the neutral lipid fraction than in the
polar lipid fraction by dietary n-3 HUFA levels. Arachidonic acid
(AA; 20:4n-6) and egg quality parameters both decreased with
increasing dietary n-3 HUFA levels. The results suggest that a high
level of n-3 HUFA in broodstock diet negatively affects egg quality
of Japanese flounder.
(Inland Station, National Research Institute of
Aquaculture, Fisheries Research Agency, Tamaki, Mie 519-0423, Japan, Tel.:
+81-596-58-6411; fax: +81-596-58-6413, e-mail: furuita@fra.affrc.go.jp)