Hen age and fatty acid composition of egg yolk lipid.

1. Total lipid, total cholesterol, and phospholipid contents per gram of egg yolk were found to be the same for eggs from 21 and 57 week-old hens. 2. In contrast, fatty acid composition of total egg yolk lipid was different for the 2 groups of hens. The contents of long-chain (20 C and 22 C) polyunsaturated fatty acids of n-6 and n-3 series were 20% to 25% higher in egg yolks from the younger hens. 3. This finding is discussed with respect to the nutritional value of eggs from hens of different ages regarding the use of egg yolk lipid in the production of infant formulae.