Utilization of Xanthophyll in Fresh-Cut and Field-Wilted, Dehydrated Alfalfa and Coastal Bermudagrass for Pigmenting Egg Yolks

Practical layer diets were formulated to contain 18.1 mg/kg total xanthophyll with 9.2 mg/kg of xanthophyll supplied by alfalfa (ALF) or Coastal bermudagrass (CBG) that was fresh-cut, field-wilted for 6 hr (daytime) or 16 hr (overnight), and then dehydrated. The diets were fed for 21 days after which eggs were collected for color and pigment analysis. Fresh-cut Coastal bermudagrass contained 84% more carotene and 36% more xanthophyll than the fresh-cut alfalfa. No consistent differences were found in xanthophyll utilization values (egg yolk xanthophyll to feed xanthophyll ratios), or CIE and L*a*b* values for yolks from hens fed diets containing the different forage products. Although alfalfa resulted in egg yolks that were slightly more red (Roche values of 10.3 vs. 9.6; a* values of 8.4 vs. 7.6) and exhibited a slightly higher dominant wavelength (580.6 vs. 580.3), these differences were thought to be due to the slightly higher xanthophyll content found in the analyzed alfalfa diets. Although total xanthophyll content may differ between these forages, or as a result of processing, when ALF or CBG products are fed to supply about equal levels of total xanthophyll, similar yolk color can be expected.