Impact of feeding flaxseed and microalgal residue on omega-3 fatty acids enrichment in hen eggs

To investigate the impact of dietary supplementation of different omega-3 polyunsaturated fatty acids(n-3 PUFAs) resources on PUFAs enrichment in hen eggs, two supplemental materials, flaxseed and oil-extracted microalgal residue of heterotrophic Schizochytrium, were added to the diet of laying hens in 3 groups. Results showed that supplementation with flaxseed and Schizochytrium residue gave rise to the increased, but different n-3 PUFAs levels in egg yolk, mainly α-linolenic acid(ALA) and docosahexaenoic acid(DHA). The ratio of n-6/n-3 PUFAs was reduced in all groups. After 14 days feeding of supplied PUFAs resources, n-3 PUFAs contents reached a plateau, and then remained constant during further supplementation in 3 experimental groups. Both the highest ALA level and DHA level were achieved in flaxseed group and microalgae group, reaching up to 353.69(±68.15) mg/egg and 301.41(± 26.76) mg/egg respectively. Moreover, the n-3 PUFAs enrichment efficiency was relatively low in flaxseed group when compared to other 2 groups. Laying rates of hens before entering peak production period could be improved by adding flaxseed but was not obviously affected by Schizochytrium residue. The egg weight, on the other hand, had no relationship with dietary supplementation. Thus, supplementation of flaxseed or Schizochytrium residue into standard feed offers an alternative choice for the production of n-3 PUFAs enriched eggs.