Requirement of n-3 long
chain polyunsaturated fatty acids for European sea bass (Dicentrarchus
labrax) juveniles: growth and fatty acid composition
A. Skalli, J.H. Robin-2004
Aquaculture, 24(1-4): 399-415
Abstract:
European sea bass juveniles (14.4±0.1 g mean weight)
were fed diets containing different levels of fish oil then of n-3 highly
unsaturated fatty acids (n-3 HUFA) for 12 weeks. The fish performance as
well as fatty acid (FA) composition of neutral and polar lipids from whole
body after 7 and 12 weeks feeding were studied. The requirements of juvenile
sea bass for n-3 highly unsaturated fatty acids (n-3 HUFA) were studied by
feeding fish diets containing six different levels of n-3 HUFA ranging from
0.2% to 1.9% of the diet, with approximately the same DHA/EPA ratio (1.5:1).
The growth rate at the end of the trial showed
significant differences. Fish fed low dietary n-3 HUFA (0.2% DM of the diet)
showed significantly lower growth than the diet 3 (0.7%), then no further
improvement (P>0.05) of growth performance was seen by elevating
the n-3 HUFA level in the diet up to 1.9% (diet 6). No difference in feed
efficiency, protein efficiency ratio or protein retention was observed among
treatments, nor in protein and total lipid content. However, the n-3 HUFA
levels in diets highly influenced fish fatty acid composition in neutral
lipid, while polar lipid composition was less affected. Comparison of polar
lipid content after 7 or 12 weeks indicated that DHA remained stable at the
requirement level, while arachidonic acid decreased with time. Results of
this experiment suggest that the requirement for growth of n-3 HUFA of
juvenile sea bass of 14 g weight is at least 0.7% of the dry diet.