Lutein and zeaxanthin are commonly referred to as the macular carotenoids, as they are localized to ocular tissues and their loss is associated with age-related macular degeneration. High carotenoid eggs have been suggested as a good dietary source of macular carotenoids, particularly lutein. In this paper we demonstrate two key proof of concept steps: transferring the high carotenoid phenotype to elite inbred backgrounds and carotenoid enrichment of eggs through feeding high carotenoid maize (Zea mays L.) grain to laying hens (Gallus domesticus). Using two inbred backgrounds and three high carotenoid donor lines, BC1S2 lines were developed with selections made based solely on visual assessment of kernel color. The 20-wk laying hen feeding trial consisted of four complete diets that varied for the maize component (i.e., a high-zeaxanthin maize line, a high-lutein maize line, and a conventional yellow maize line with and without a commercial lutein [Oro-glo] supplement) with eggs samples collected every 4 wk. High-carotenoid maize diet treatments yielded carotenoid concentrations in egg yolks that were approximately fourfold higher than those achieved with the conventional maize feed control and were found to be equally available to the laying hen as a lutein feed additive used as a positive control. While phenotyping by high pressure liquid chromatography (HPLC) cannot be completely eliminated, visual selection increases the proportion of high-carotenoid phenotypes and it appears that transferring the high carotenoid phenotype into elite inbred lines is relatively straightforward.
Burt, A.J.; Caston, L.; Leeson, S.; Shelp, B.J.; Lee, E.A. Development and Utilization of High Carotenoid Maize Germplasm: Proof of Concept. Crop Science (2013) 53 (2) 554-563. [DOI: 10.2135/cropsci2012.02.0069]