Dynamics of omega‐3 long chain polyunsaturated fatty acid incorporation in egg yolk by autotrophic microalgal supplementation

Four different microalgal species ( Phaeodactylum tricornutum , Isochrysis galbana , Nannochloropsis oculata , and Chlorella fusca ) in two doses (125 and 250 mg ALA + EPA + DHA per 100 g feed) were supplemented to the diet of laying hens to examine the impact on the dynamics of long chain omega‐3 polyunsaturated fatty acid (n‐3 LC‐PUFA) incorporation in the egg and yolk color changes. However, no major differences in dynamics of these parameters were observed between the species and between the supplementation doses. The maximum n‐3 LC‐PUFA content was observed after 14 days supplementation, except for the highest supplementation doses of Phaeodactylum and Nannochloropsis . In this case, the maximal value was obtained after 10 days. After a few days of wash‐out, still an enrichment of n‐3 LC‐PUFA was observed, except for the lowest dose of Chlorella . Due to the enrichment of carotenoids in the egg, originating from microalgae, the yolk color changed. Concomitant with the delay of n‐3 LC‐PUFA incorporation, also a delay of yolk color changes was observed. After 7 days of microalgal supplementation, again a stable yolk color was obtained and after 10 days of wash‐out, the yolk color returned to the standard yolk color in most cases. Practical applications: Knowledge of the dynamics of n‐3 LC‐PUFA and carotenoid incorporation is very important to know how long the microalgae need to be supplemented in to the diet of the laying hens in order to find a compromise between omega‐3 and pigment levels to be stated on eggs' labels and the cost of the treatment. From an economical viewpoint, it is interesting to evaluate the supplementation of different microalgal species and different doses, since this could lead to different impacts on the economical aspect of the use of microalgae in the diet of laying hens. Microalgae were supplemented into the diets of laying hens and the impact of this supplementation on long chain omega‐3 polyunsaturated fatty acid incorporation into the egg and yolk color changes was examined.