Utilization and Yolk Coloring Capability of Xanthophylls from Synthetic and High Xanthophyll Concentrates

Four marigold products, a bixin product, and two synthetic xanthophylls, canthaxanthin and β-apo-8′-carotenal, were evaluated for their effects on xanthophyll utilization and coloring capability in egg yolks. The selected sources, obtained as commercially available products, were added to a yellow corn basal diet containing 11 mg total xanthophyll/kg diet, and all except bixin were formulated to supply an additional 13 mg total xanthophyll/kg of test diet. Laying hens were fed control and test diets for a 21-day repletion period prior to egg collection for yolk xanthophyll and color analyses. Yolk xanthophyll content was determined by the same procedure used for feed xanthophyll analysis, and yolk color determined using the Roche color fan (RCF) and reflectance colorimetry. Canthaxanthin and β-apo-8′-carotenal resulted in the largest increases in coloring capability and the highest and lowest xanthophyll utilizations, respectively. Within the group of marigold products, there was no difference in xanthophyll utilization. The bixin product, when used alone or in combination with a marigold concentrate, produced no effect on xanthophyll utilization or yolk color.