Effects of different levels of clove bud (Syzygium aromaticum) on yolk biochemical parameters and fatty acids profile, yolk oxidative stability, and ovarian follicle numbers of laying hens receiving different n-6 to n-3 ratios

•Fish oil and clove bud decreased egg yolk cholesterol, triglyceride and ω-6/ω-3 ratio.•Clove bud could improve n-3-enriched eggs oxidative stability in different conditions.•Fish oil stimulated the impressionability of egg yolk to lipid peroxidation.•Clove bud suppressed egg MDA content and enhanced yolk vitamin E concentration.