Performance and egg quality of light laying hens fed with canthaxanthin and marigold flower extract

The aim of this study was to determine the best level of inclusion of natural (marigold flower extract) and synthetic (canthaxanthin) pigments in the diet of light laying hens from 75 to 85 weeks old in terms of effects on performance, egg quality, and economic viability of production. A total of 288 laying hens were used in a completely randomized design, with a 4 x 4 factorial arrangement, with four levels of marigold flower extract (2.10; 2.40; 2.70; 3.00 ppm) and four of canthaxanthin (0. 40; 0.70; 1.00; 1.30 ppm), with three replications and six hens per experimental unit. The feed conversion by mass of eggs, egg mass, and egg laying rate showed linear improvement with the inclusion of canthaxanthin. The yolk index showed a quadratic effect with the inclusion of marigold and canthaxanthin, presenting a better estimate with diets containing 2.60 ppm/kg of marigold feed and 0.95 ppm/kg of canthaxanthin feed. The percentage of yolk and the Haugh unit increased linearly with the rising levels of marigold, whereas the percentage of albumen decreased linearly. In the evaluation of the YolkFan DSM® and the redness/yellowness, chroma (a*) presented a quadratic effect for the inclusion of marigold (2.73 and 2.80 ppm/kg of feed) and linear increase with canthaxanthin. It was concluded that the best yolk index was with 2.60 ppm/kg marigold flower extract and 0.95 ppm/kg canthaxanthin in the diet of light laying hens from 75 to 85 weeks old.