Lipid fatty acid composition and oxidative susceptibility in eggs of hens fed a fish fat diet supplemented with vitamin E, C, or synthetic antioxidant

Abstract

Hy-Line laying hens from weeks 24 to 67 of age were fed a 0.3% fish fat diet with or without vitamin E, ascorbic acid, or synthetic antioxidants. Lipid composition, cholesterol and a-tocopherol levels and degree of fat oxidation (TBA-RS) in yolk during storage were investigated. Dietary fish fat led to an increased n-3 PUFA content in yolk lipids (from 14.4 to 21.5 mg kg -1) and to a lower n-6: n-3 PUFA ratio (from 7.75 to 4.97) without any effect on the level of cholesterol in eggs. The supplements tested exerted no influence on the composition of egg fatty acids. The dietary vitamin E supplement increased α-tocopherol in egg yolk from 24.2 to 68.3 mg kg -1 and improved fat stability during storage for 15 and 42 days. Similar stabilizing properties were observed after supplementing the feed with synthetic antioxidants (BHT, BHA and EQ) and to a lesser degree when vitamin C was added.