N-3 fatty acid enrichment of table eggs by adding a fish oil preparation (Nordos Fat®) to the diet of laying hens

Experiments were conducted to study the effect of a dietary fat preparation (Nordos Fat®) rich in n-3 fatty acids on the fatty acid composition of the yolk lipids in table eggs. This preparation was added to a commercialdiet for laying hens at concentrations of 1.0, 1.5 and 2.0%. The hens were fed these diets for 8 weeks. Eggs were collected randomly before the treatment and at the end of weeks 1, 2, 4 and 8 of the experimental period. The fatty acid composition of the egg yolk was determined by gas chromatography. Supplementation with the fat preparation markedly increased either the proportions or the concentrations of n-3 fatty acids in the egg yolk. DHA showed the highest increase among the n-3 fatty acids. However, the proportions and concentrations of n-6 fatty acids, particularly C20:4n-6, significantly decreased when the fat preparation was added to the diet. Although the concentration of long-chain fatty acids showed the highest values in the egg yolks of hens fed on 2% fat supplementation, the eggs of hens fed on diets including either 1.0 or 1.5% of the fat also contained high levels of these fatty acids. Accordingly, the fish oil preparation tested in this experiment may be a good source for increasing the concentrations of long-chain n-3 fatty acids in table eggs.