Effect of n - 3 HUFA level in broodstock diets on egg quality of gilthead sea bream (Sparus aurata L.)

Abstract

A variety of morphological, biological and biochemical parameters of freshly spawned eggs of gilthead seabream (Sparus aurata L.) were studied to determine the optimum n − 3 HUFA level in broodstock diets necessary to obtain a high-quality spawn. The effect of very high dietary n − 3 HUFA levels on fish reproduction was also investigated. Broodstock were separated into 8 groups and fed four diets containing different levels of n − 3 HUFA, ranging from 1.13 to 3.15%, for 3 months. Spawning and egg qualities were evaluated daily by 7 parameters. Besides, 8 samples of eggs were taken during the experimental period and were analyzed for proximate and fatty acid composition. After 3 weeks of feeding, significantly improved spawning quality in the broodstock fed 1.6% n − 3 HUFA was observed in terms of fecundity, hatching and larval survival. Unfertilized egg rates were significantly reduced by the increase in dietary 20:5n − 3. The highest level of dietary n − 3 HUFA was associated with a decreased fecundity and yolk sac hypertrophy in just hatched out larvae, n − 3 HUFA content in the eggs showed a positive correlation with dietary n − 3 HUFA, mainly due to the change in 20:5n − 3 content of the eggs.