What specific dietary component directly links to the yolk color associated with egg quality?

Carotenoids in the feed

The visual characteristic of yolk color, often used as an indicator of perceived quality by consumers, is directly and chemically linked to the presence of carotenoids within the laying hen's diet. Carotenoids are pigments derived from various feed ingredients, such as grass and insects, which the chickens consume. When hens have access to a more varied diet that is rich in these pigments, they deposit them into the yolk, resulting in a richer, often deeper golden hue. While factors like active foraging contribute to this varied diet, the underlying nutritional components responsible for the color itself are these specific pigments. This mechanism explains why localized feed sources, which inherently differ in carotenoid content, drive flavor and visual variation across different geographical production areas.