Docosahexaenoic Acid Is Superior to Eicosapentaenoic Acid as the Essential Fatty Acid for Growth of Grouper, Epinephelus malabaricus

Abstract

Juvenile grouper (Epinephelus malabaricus) were fed seven experimental diets, one control diet and one reference diet for 12 wk to determine the dietary requirement of grouper for docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. Each of the seven diets contained 1 g/100 g DHA and EPA in various combinations and 9 g/100 g tristearin. The control diet contained 1 g/100 g trilinolenin and trilinolein (3:1, wt/wt), and no supplemental EPA or DHA. The reference diet contained only natural oils from a mixture of cod liver oil, linseed oil and safflower oil at a ratio of 2:1:1 (wt/wt/wt). Significant differences (P < 0.05) in growth were observed among the dietary treatments but not in survival rate or relative liver weight. Only the diet with the highest DHA/EPA ratio (3:1) promoted significantly greater growth than the control diet. Purified EPA and DHA did not perform better in promoting growth than did the impure EPA and DHA oils. Enhanced growth was observed when the dietary DHA/EPA ratio was greater than 1, indicating that DHA was superior to EPA in promoting fish growth. Neutral lipid (NL) was the predominant lipid fraction (>70%) in both liver and muscle. Tissue NL/polar lipid did not differ among groups except the reference diet group that had a higher ratio (P < 0.05). DHA and EPA levels in the grouper tissues, especially muscle, were highly reflective of dietary levels of DHA and EPA, indicating that direct incorporation was likely. In addition, the 20:1(n-9), concentration in NL fractions seems to be an appropriate indicator of dietary essential fatty acid deficiency in grouper.

The influence of Iraqi mothers' socioeconomic status on their milk-lipid content

“…The n 6 FAs are commonly present in vegetable oils and eggs (especially C 20:4 n 6 in lecithine) and n 3 FAs are commonly present in fish oil (Flayeh, 2000;Wu et al, 2002). A noticeable quantity of n 6 FAs was detected in Iraqi mothers' breast-milk, but it was still lower than that of most milk samples from other countries (Innis, 1991;Jorgensen et al, 1995;Jensen, 1999;Wu et al, 2002). Iraqi breast-milk was particularly poor in n 3 FAs.…”

Fatty-acid composition of the colostrum and serum of fullterm and preterm delivering Iraqi mothers

“…In addition, the percentage of DHA and the ratio of n3/n6 in PT colostrum are lower than in FT colostrum. This indicates that there is a decrease in the absolute and relative amounts of DHA, the most important FA for infant growth (Wu et al, 2002). Generally, it has been observed that the level of n3/n6 for both groups (mainly PT-group) is lower than that recommended by WHO for infant optimum nutrition (0.1).…”

Dietary docosahexaenoic acid is more optimal than eicosapentaenoic acid affecting the level of cellular defence responses of the juvenile grouper Epinephelus malabaricus

“…The basal diet was composed of solvent-extracted fishmeal 651·5 g kg 1 , solvent-extracted corn starch 43·5 g kg 1 , solvent-extracted -starch 43·5 g kg 1 , vitamin mixture 40 g kg 1 , mineral mixture 80 g kg 1 , -cellulose 11·5 g kg 1 and carboxymethyl-cellulose (binder) 30 g kg 1 [30]. Proximate analysis of the basal diet showed a crude protein concentration of 52·3%, moisture content of 3·5%, ash content of 9·8% and a residual amount of lipid (0·9%).…”