Hens ranked as highly feed efficient have an improved albumen quality profile and increased polyunsaturated fatty acids in the yolk1

Abstract

The shelf life of eggs that 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 is highly feed efficiency (HFE) exhibits 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 wk) using 140 Isa Brown layers (28 wk old), the 10 most efficient (FCR < 1.99 ± 0.05) and the 10 least efficient (FCR > 2.30 ± 0.05) hens were identified and designated as HFE and low feed efficiency (LFE) groups, respectively. Internal quality and composition were determined on eggs (n = 10 per group) stored at 15 °C for 0, 14, and 28 d. At 0, 14, and 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 with 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 marker (thiobarbituric acid reactive substances; TBARS) values both in fresh and in 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.