Comparative Effects of Organic and Nano-Selenium on Egg Quality and Antioxidant Capacity in Layer Hens

This study evaluates the effects of dietary selenium (Se) sources—sodium selenite (SS), nano-selenium (Nano-Se), selenocysteine (Se-C), and selenomethionine (Se-Met)—on production performance, egg quality, preservation characteristics, yolk Se content, and antioxidant capacity in Hy-Line Grey laying hens. A total of 450 healthy 18-week-old Hy-Line Grey laying hens were allocated to five groups (basal diet without Se, 0.30 mg/kg SS, Nano-Se, Se-C, or Se-Met) for an 8-week trial after a 4-week Se-depletion phase. The key results demonstrate that while no significant differences were observed in the feed intake, egg production rate, or egg weight among the groups (p > 0.05), organic Se (Se-C, Se-Met) and Nano-Se significantly improved the yolk color (p < 0.05) and yolk index (p < 0.05) and mitigated declines in the albumen height and Haugh unit during storage. Notably, Nano-Se exhibited superior efficacy in enhancing yolk color and antioxidant enzyme activity (p < 0.05). Furthermore, organic Se and Nano-Se increased yolk Se deposition (p < 0.05), increased yolk antioxidant enzyme activity (p < 0.05), and reduced lipid peroxidation (p < 0.05). These findings indicate that supplementing 0.3 mg/kg organic Se or Nano-Se enhances egg quality, extends shelf life, and improves antioxidant capacity, offering a sustainable strategy for selenium-enriched egg production.