Effect of oil blends with near equal increases in 18 carbon n-3 and n-6 fatty acids on fatty acid profile of eggs

The present study aimed to compare the near equal substitution of 18 carbon omega-3 (n-3) and omega-6 (n-6) fatty acids (FA) on their elongation and deposition into the egg yolks and tissues of laying hens. Fifty 40 wk old Hy-line W-36 white leghorn hens were randomly allocated to five experimental groups (10 hens per group). The basal diet was a corn-soybean meal mash layer diet containing 3.14 % conventional soybean oil (SOY), control, and the experimental diets were prepared by substituting 1.25 % of the SOY for high-stearidonic acid (SDA; 18:4n-3) soybean oil or a high-alpha linolenic acid (ALA; 18:3n-3), a high-gamma linolenic acid (GLA; 18:3n-6), or a high-linoleic acid (LA; 18:2n-6) oil blend. No adverse effects on laying performance, egg components, and tissue weight were reported. Hens fed high-SDA and high-ALA diets showed higher levels of total n-3 FA than control and other treatments. Total n-3 highly unsaturated FA (HUFA) was increased in the yolk and breast muscle of hens fed high-SDA compared to the high-ALA. Similarly, the high-GLA and high-LA diets increased the total n-6 and total n-6 HUFA in yolk, liver, and breast than other diets. The total n-6 HUFA was the greatest in the yolk and breast muscle of hens fed high-GLA diet. The efficiency of synthesis and transfer of n-3 and n-6 HUFA was greater in the yolk of hens fed high-SDA and high-GLA diets than other treatments. Hepatic expression of FASN and ELOV2 was higher in SDA than the other UFA treatments. Overall, the high-SDA and high-GLA diets more efficiently enriched the yolk and body tissues with HUFA. Further investigation on the most efficient level of inclusion into the diet might be needed.