Impact of microalgal feed supplementation on omega-3 fatty acid enrichment of hen eggs

In many Western countries, the average intake of the health beneficial omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is below the recommended level, raising interest in food enrichment with n-3 LC-PUFA. To that end, the impact of feed supplementation with EPA rich autotrophic microalgal biomass on n-3 L-PUFA enrichment of eggs was studied. Hens were divided in three groups receiving different diets for 28 days: a standard diet (C) for laying hens, (C) supplemented with 5.0% spray dried Nannochloropsis gaditana, and (C) to which 10.0% of these microalgae were added. Microalgal EPA was hardly accumulated in yolk lipids, but preferentially converted to DHA and deposited in yolk phospholipids. The efficiency of deposition of microalgal n-3 LC-PUFA to eggs was rather low. Switching back to standard feed ensured that the n-3 LC-PUFA level obtained in enriched eggs decreased back to that of the control eggs. Moreover, the colour of egg yolk shifted from yellow to more orange-red, which is presumably due to transfer of microalgal carotenoids to egg yolk. Thus, the use of autotrophic microalgae as supplement for standard feed offers an alternative to current sources for the production of DHA enriched eggs