Effect of dietary essential
fatty acids on growth, body composition and blood chemistry of juvenile
starry flounder (Platichthys stellatus)
S.-M. Lee, J.H. Lee, K.-D. Kim-2003
Aquaculture, 225(1-4): 269-281
Abstract:
A 10-week feeding experiment was conducted to
investigate the effects of dietary lipid source and n-3 highly unsaturated
fatty acids (n-3 HUFA) level on growth, body composition and blood chemistry
of juvenile starry flounder. Three replicate groups of fish (average weight
1.9 g) were fed diets containing different n-3 HUFA levels ranging from 0.0%
to 2.7% adjusted by either lauric acid as sole lipid source or different
proportions of corn oil, linseed oil and squid liver oil at 10% of total
lipid. Survival was not affected by dietary lipid source or n-3 HUFA level.
Weight gain, feed efficiency and protein efficiency ratio of fish fed the
diets containing squid liver oil were significantly higher than those fed
the diets containing lauric acid, corn oil or linseed oil as the sole lipid
source. However, there were no significant differences in weight gain, feed
efficiency and protein efficiency ratio among fish fed the diets containing
different n-3 HUFA levels ranging from 0.6% to 2.7%. Dietary n-3 HUFA
requirement when using a broken line model was estimated at 0.9% for weight
gain of fish. Crude lipid content of fish fed the diet containing lauric
acid was significantly lower than that of other groups. Fatty acid
compositions of neutral and polar lipid of fish were directly reflected by
dietary fatty acid composition. The highest 14:0, 18:2n-6, 18:3n-3 and n-3
HUFA contents were observed in fish fed the diets containing lauric acid,
corn oil, linseed oil and squid liver oil, respectively. The contents of n-3
HUFA in fish linearly increased with increasing dietary squid liver oil.
Plasma cholesterol concentration and aspartate aminotransferase activity
were affected by dietary lipid sources. These results indicate that dietary
n-3 HUFA are essential and a value of at least 0.9% of n-3 HUFA in the diet
could be recommended for optimum growth and efficient feed utilization of
juvenile starry flounder.