Enrichment of eggs with lutein.

Lutein is being considered as a nutrient for prevention of macular degeneration in the aging population. Two experiments were designed to study the transfer efficiency of lutein from the layers' diet into the egg. In experiment 1, laying hens were fed corn-soy diets supplemented with 0, 125, 250, 375, 500, 625, 750, or 1000 ppm of lutein. After 30 d, eggs were collected and assayed for lutein. In a second study, layers were fed corn-soy diets or diets containing corn gluten meal and alfalfa, with or without added flaxseed. Diets in experiment 2 were supplemented with 0, 125, 250, or 500 ppm of lutein. Adding lutein to the layers' diet resulted in a significant (P < 0.01) increase in Roche color score of yolk within 7 d of supplementation. In experiment 1, lutein was transferred into the yolk (P < 0.01) increasing from a basal level of 0.3 mg to 1.5 mg/60 g of egg. However, there was no significant (P > 0.05) increase in yolk lutein with diet supplements >375 ppm. In the second experiment, using corn gluten meal and alfalfa further increased lutein content that leveled off at 2.2 mg/60 g of egg with a diet supplement of 500 ppm of lutein. Adding flax to these diets seemed to depress yolk lutein content. Yolk lutein content can be increased, although further studies are needed to investigate the major decline in transfer efficiency seen with higher levels of dietary supplementation.