1990 Volume 56 Issue 8 Pages 1263-1269
A feeding experiment was conducted to compare the EFA value between eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in juvenile red seabream, and to determine their requirements for both fatty acids by feeding them defatted fish meal diets containing different levels of EPA and/or DHA ranging from 0 to 1% in diet.
Juvenile red seabream fed a diet without supplemental EFA began to show a high mortality and poor appetite after one week feeding. The cumulative mortality of this group was 46% after 24 days. The growth and feed efficiency were effectively improved by elevating EPA or DHA levels to 1% or 0.5% in the diet, respectively. However, further elevation of the DHA level from 0.5 to 1% and addition of both EPA and DHA in diets at levels of 0.25 and 0.5% each did not result in further improvement of these parameters. The hepatosomatic index was high in the fish fed low levels of EPA or DHA and was reduced by elevating EPA levels to 1% in diets, although DHA was more effective than EPA.
Thus, the requirement of EPA and DHA was estimated to be around 1% and 0.5% in diet for juvenile red seabream, respectively. The EFA efficiency of DHA was also found to be about twice as high as that of EPA, and there was no additive effect of EPA and DHA on growth and feed efficiency.