Effects of Pigments Extracted from the Marigold Flower on Egg Quality and Oxidative Stability of the Egg Yolk Lipids in Laying Hens

This research aimed to compare the effects of pigments extracted from dried petal meal of marigold flower and synthetic pigments on productive performance of laying hens, egg quality and antioxidant properties of the egg. A total of 64 laying hens, aged 75 weeks, were distributed in a completely randomized design in 4 treatments and 4 replications containing 4 hens per cages. Experimental groups contained: (1) basal diet without pigment; (2) basal diet + 25 ppm commercial synthetic pigment (red canthaxanthin); (3) basal diet + 20 ppm total carotenoids extracted from marigold flower and (4) basal diet + 40 ppm total carotenoids extracted from marigold flower. During a 8-weeks trial, egg production (number and weight), egg quality (height and diameter of the yolk, albumen height, thickness, weight of eggshell, Haugh unit), yolk color index (two methods of Roche yolk color fan and hunter lab instrument) and oxidative stability of egg yolk lipids (based on malondialdehyde value at fresh, 0 and 21th days of room temperature of storage) were measured and analyzed in a completely randomized design. There was no significant difference for egg production and its quality between experimental and control groups. However, the yolk color index in hens consumed natural or synthetic pigment was significantly higher (P<0.01). The oxidative stability of yolk in hens being fed marigold pigment improved significantly after 3 weeks (P<0.05). Consequently, although the intensity of yolk color induced by xanthophyll of marigold flower was lower than synthetic pigments, the yolk color is acceptable for Iranian consumers. In conclusion, the use of marigold as a natural colourant or incorporating its derived antioxidant components in laying hens diets should be economically evaluated.