title: Influence of high vitamin E dosages on retinol and carotinoid concentration in body tissues and eggs of laying hens.
abstract: The aim of the study was to contribute to the discussion of overdosing vitamin E in laying hens. A total of 45 laying hens, divided into 5 groups were fed diets supplemented with either 0; 100; 1000; 10,000 or 20,000 mg dl-alpha-tocopheryl acetate/kg diet over a period of 10 weeks. Concentrations of vitamins A and E were measured in plasma, various tissues and egg yolk. Furthermore egg yolk colour and some carotinoids were measured in egg yolks. None of the vitamin E doses significantly influenced performance of the hens. As expected, vitamin E concentration in plasma, all tissue samples and egg yolk was significantly increased with increasing tocopherol content in the diet. The egg yolk showed the highest vitamin E concentration, followed by liver and muscles. Feeding 1000 mg alpha-tocopheryl acetate per kg diet resulted in an increase of vitamin A concentration in the liver. Very high doses (10,000 and 20,000 mg/kg diet) significantly decreased retinol concentration in the liver and egg yolk, as well as carotinoid concentration in the egg yolk. The lower carotinoid concentration in egg yolk resulted in a decreased intensity of egg yolk colour. A prooxidative and/or competitive effect of very high doses of vitamin E with other fat soluble substances has been discussed.
authors.affiliation: Institute of Animal Nutrition of the Federal Agricultural Research Centre, Braunschweig (FAL), Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sünder
authors.forename: G
authors.initials: G
authors.lastname: Flachowsky
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism*; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D003116:Color; D004305:Dose-Response Relationship, Drug; D004530:Egg Yolk / Q000737:chemistry*; D005260:Female; D008099:Liver / Q000737:chemistry; D009132:Muscles / Q000737:chemistry; D010058:Oviposition; D010084:Oxidation-Reduction; D014018:Tissue Distribution; D014801:Vitamin A / Q000378:metabolism*; D014810:Vitamin E / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids