Enriching laying hens eggs by feeding diets with different fatty acid composition and antioxidants

The current study was conducted to evaluate egg quality, egg yolk fatty acids, health-related indices and antioxidants from laying hens' eggs fed different combined vegetable by-products, rich in fatty acids and antioxidants. One hundred twenty 50 weeks-old Tetra SL laying hens were divided into three groups. They were given daily a standard diet (Control, C), a diet containing 9% rapeseed meal with 3% grapeseed meal (T1 diet), or a diet containing 9% flaxseed meal and 3% sea buckthorn meal (T2 diet). Hen production performances, egg quality, egg yolk fatty acids total polyphenols content and antioxidant capacity were determined. The T1 diet significantly reduced the egg yolk content of palmitic acid from 76.615 mg (C) to 46.843 mg (T1) and that of oleic acid from 788.13 mg (C) to 682.83 mg (T1). Feeding flaxseed and sea buckthorn meals significantly increased the egg yolk content of alpha-linolenic acid in T2 yolks (35.297 mg) compared with C yolks (4.752 mg) and that of docosahexaenoic acid (DHA) from 16.282 mg (C) to 74.918 mg (T2). The atherogenicity indices (AI) were not significantly affected, whereas the thrombogenicity indices (TI) decreased significantly (p < 0.0007) from 0.72 (C) to 0.60 (T1) and 0.66 (T2), respectively. Adding this combination of meals to the hens' diets, increased the total polyphenol content and antioxidant capacity in T1 and T2 eggs compared to C eggs. The significant enrichment of eggs with n-3 fatty acids and antioxidant capacity, as well on the health-related indices especially from T2 eggs, represents a potential functional feed ingredient in poultry feeding, to obtain eggs as functional food.