Comparison of unsaturated fatty acid content in egg yolk. *OCE, ABBCE, BBBCE respectively represent Ordinary chicken eggs, A brand black-bone chicken eggs, B brand black-bone chicken eggs. UFA, MUFA, PUFA, ω-6PUFA, ω-3PUFA respectively represent Unsaturated fatty acid, Monounsaturated fatty acid, Polyunsaturated fatty acid, ω-6 Polyunsaturated fatty acid, ω-3 Polyunsaturated fatty acid. Unmarked letters indicate no significant differences.