title: Effect of vitamin E and A supplementation on egg yolk alpha-tocopherol concentration.
abstract: The objective of this study was to asses the effect of dietary dl-alpha-tocopheryl acetate (alpha-TAC) and vitamin A supplementation on egg yolk alpha-tocopherol (alpha-T) concentration. A total of 96 ISA brown hens (a brown-egg laying hen), 32 wk of age, was used. Eight concentrations of alpha-TAC (0, 20, 40, 80, 160, 320, 640, and 1,280 IU/kg diet) were included in a corn-soybean meal-based diet containing 4,000 IU of vitamin A/kg diet. Production parameters were not affected by dietary treatment. Interhen variation in yolk alpha-T concentration increased at higher dietary intakes. Logarithmic transformation stabilized variance and showed the existence of a linear relationship between dietary alpha-TAC supplementation level and alpha-T egg yolk concentration (P < 0.001). As the dietary concentration of alpha-TAC rose, efficiency of uptake of alpha-T from feed to yolk decreased linearly (P < 0.001). A parallel experiment was carried out in which four additional groups of hens were fed diets containing four levels of dietary alpha-TAC (0, 40, 160, and 640 IU/kg) and 40,000 IU vitamin A/kg diet. A significantly lower egg yolk alpha-T concentration was found in hens fed diets including the highest level of vitamin A supplementation (P < 0.001). No interaction of dietary alpha-TAC and vitamin A concentrations was observed on egg yolk alpha-T concentration. No effect of dietary treatment was observed on yolk oxidation and other egg quality characteristics.
authors.affiliation: Departamento de Producción Animal, Universidad Politécnica de Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Grobas
authors.forename: J
authors.initials: J
authors.lastname: Méndez
authors.forename: Bote C
authors.initials: BC
authors.lastname: Lopez
authors.forename: Blas C
authors.initials: BC
authors.lastname: De
authors.forename: G G
authors.initials: GG
authors.lastname: Mateos
mesh_terms: D000818:Animals; D002645:Chickens; D004032:Diet; D019587:Dietary Supplements; D004530:Egg Yolk / Q000737:chemistry*; D005260:Female; D013025:Glycine max; D024505:Tocopherols; D014801:Vitamin A / Q000008:administration & dosage*; D003313:Zea mays; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000032:analysis*
chemical_list: D014801:Vitamin A; D024502:alpha-Tocopherol; D024505:Tocopherols