The experiment was conducted to investigate the egg yolk color of commercial laying hens fed different levels of marigold petals and leaves. A total number of 48 Hy-Line Brown layers aged at 80 weeks were randomly distributed into 6 dietary treatments having 4 replications, each of 2 birds, and fed 5 different levels of marigold petal and leaves (0.5 and 1% of yellow marigold petal, 2 and 4% of orange marigold petal and 1% of marigold leaves) for the duration of 6 weeks. The influence of test ingredients on production characteristics of laying hens, external (shape index, eggshell thickness) and, internal (egg yolk color score, yolk index, albumen index, Haugh unit) egg quality characteristics were investigated simultaneously. Yolk color was improved significantly for the addition of marigold petals and leaves as compared to the control diet. Marigold feeding to Hy-Line Brown up to 4% did not show any adverse effects on egg production and egg weight and there were no significant variations concerning body weight. Egg yolk color was measured by the Roche Yolk Color Fan and by CIE*(L*a*b*) colorimetric method. A significant increase in egg yolk color was observed in the treatments that received the yellow and orange marigold petal and marigold leaves (P
Key words: Laying hens, Yolk color, Marigold petal, Marigold leaves, Pigmentation
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