ALPHA-TOCOPHEROL, BETA-CAROTENE, AND RETINOL ENRICHMENT OF CHICKEN EGGS

Due to the numerous health benefits associated with consumption of ant ioxidants such as alpha-tocopherol and beta-carotene, an experiment wa s conducted to determine dietary levels that would significantly enhan ce their concentration in chicken egg yolks. In the experiment, 127 Si ngle Comb White Leghorn laying hens were divided into treatment groups (n = 40 per treatment group) and fed diets containing 0, 50, 100, 200 , or 400 mg /kg beta-carotene, dl-alpha-tocopheryl acetate, or their c ombination. Yolk alpha-tocopherol increased (P < .05) from the control level of 144 mug/g of yolk to 477 mug/g of yolk when 400 mg dl-alpha- tocopheryl acetate/kg of diet was supplemented. Yolk retinol levels in creased (P < .05) from 11.6 mug/g of yolk in controls to 13.9 mug/g of yolk at 200 mg beta-carotene/kg of diet. Beta-carotene content in the yolk also increased (P <.05) from .14 mug/g of yolk in controls to 5. 19 mug/g of yolk at 200 mg beta-carotene/kg of diet. Supplemental beta -carotene markedly decreased the yolk deposition of alpha-tocopherol w hen the two compounds were fed together. Egg production, egg weight, a nd egg yield were not affected by dietary supplementations. Although t he data indicated that it is possible to significantly increase the co ncentration of all three compounds in chicken eggs, because of the rel ative expense involved it may not be commercially viable to increase e gg yolk concentrations of beta-carotene or retinol by supplementing be ta-carotene in the diet.