Hens ranked as highly feed efficient have an improved albumen quality profile and increased polyunsaturated fatty acids in the yolk

The shelf-life of eggs which contain elevated levels of polyunsaturated fatty acids (PUFA) is compromised due to the relative instability and therefore greater potential for lipid peroxidation of unsaturated fatty acids (FA). Poultry that are highly feed efficient (HFE) exhibit higher systemic levels of antioxidant enzymes, and therefore may produce eggs with improved albumen quality and favorable FA profiles that are stable over time. We tested the hypothesis that HFE laying hens produce eggs with improved internal egg quality and a favorable yolk FA profile prior to and following storage. Following an initial screening phase (7 weeks) using 140 Isa Brown layers (28 week old), the 10 most efficient (FCR 2.30 ± 0.05) hens were identified and designated as high feed efficiency (HFE) and low feed efficiency (LFE) groups respectively. Internal quality and composition were determined on eggs (n = 10 per group) stored at 150C for 0, 14 and 28 d. At 0, 14 & 28 d, the albumen weight, albumen height, Haugh unit (HU) and albumen:yolk ratio of eggs from the HFE group were significantly higher (P < 0.01), whereas the eggs from the LFE group had heavier (P < 0.01) yolk than the HFE group. After 28 d storage, the yolk color score of the LFE group was lower (paler; P < 0.05) compared to that of the HFE group. The relative proportions of total PUFA and the ratio of total PUFA and total saturated fatty acids (SFA) were higher (P < 0.05) in HFE group of eggs. The LFE group of eggs contained higher (P < 0.05) levels of lipid peroxidation markers (thiobarbituric acid reactive substances; TBARS) values both in fresh and stored eggs. The results suggest that HFE hens produce eggs with greater albumen quality and higher levels of yolk PUFA both at lay and after storage