Applied Research Note: “The impact of orange corn in laying hen diets on yolk pigmentation and xanthophyll carotenoid concentrations on a percent inclusion rate basis”

Abstract

SUMMARY: Consumers associate nutritional quality and potential health benefits with yolks showing deeper colors produced by healthy layers fed a well-balanced, nutrient-rich diet. However, cereals and oilseed meals generally used in poultry feed do not provide sufficient carotenoids to achieve deeper yolk colors, thus carotenoid additives may be supplemented. High carotenoid corn genotypes have been developed, and when included in poultry diets increase carotenoid concentrations in yolks. Seven different diets were fed to 210 Novogen White laying hens over 21 d. Each diet had 5 replicates of 6 hens housed in conventional cages. The only difference in diet treatments was percent inclusion rate of orange corn or inclusion of a carotenoid additive (Oro Glo). Yolk color was assessed by colorimeter and DSM YolkFan. Yolk carotenoid concentrations were determined by high performance liquid chromatography. Yolks from hens fed diets with a 100% orange corn inclusion rate had the highest YolkFan scores and total xanthophyll levels at the end of the study. Orange corn inclusion rate showed a linear relationship with colorimeter a* values (r = 0.96) and YolkFan scores (r = 0.90) for egg yolks. Orange corn inclusion of 50 and 75% produced yolks with a* axis color value equivalent to that found in yolks from hens fed 100% yellow corn plus 35 g/kg of Oro Glo. Data indicates that orange corn can be a suitable replacement for carotenoid additives. A 50 to 75% orange corn inclusion could be sufficient to achieve yolk colors similar to diets that involve supplementation with a carotenoid additive.

Keywords

• orange corn
• carotenoids
• yolk color
• eggs
• laying hens