title: Effects of zinc and vitamin A supplements on plasma levels of thyroid hormones, cholesterol, glucose and egg yolk cholesterol of laying hens.
abstract: The effects of zinc and vitamin A supplementation to the diet on some blood metabolites were evaluated in Hisex brown laying hens from 56 weeks to 68 weeks of age. A total of 130 birds were divided into two main groups according to vitamin A treatment (0 and 3.44 mg retinyl acetate kg(-1) feed, respectively), each consisting of 65 hens. Hens in both of the main groups were then divided into five zinc treatment groups (0, 25, 50, 100 and 200 mg zinc kg diet(-1) respectively) of 13 hens each. It was observed that plasma T4, T3 and total cholesterol levels were affected by only zinc supplementation. While 100 and 200 mg Zn kg(-1) decreased plasma T4 level compared to control value, plasma T3 level was reduced by 100 mg Zn kg(-1) compared to groups fed less Zn. Adding 50 and 200 mg Zn kg(-1) to the diet increased plasma total cholesterol level in the birds compared to other groups. Vitamin A, zinc, and their interaction did not influence the concentration of plasma high-density lipoprotein (HDL)-cholesterol, glucose and egg yolk cholesterol in laying hens.
authors.affiliation: Department of Physiology, University of Mustafa Kemal, Faculty of Veterinary Medicine, Hatay, Turkey. sule_kaya@hotmail.com
authors.forename: S
authors.initials: S
authors.lastname: Kaya
authors.forename: T
authors.initials: T
authors.lastname: Keçeci
authors.forename: S
authors.initials: S
authors.lastname: Haliloğlu
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002645:Chickens / Q000097:blood / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D019587:Dietary Supplements; D004530:Egg Yolk / Q000378:metabolism*; D005260:Female; D011897:Random Allocation; D013963:Thyroid Hormones / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014801:Vitamin A / Q000378:metabolism / Q000494:pharmacology*; D015032:Zinc / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D013963:Thyroid Hormones; D014284:Triiodothyronine; D014801:Vitamin A; D002784:Cholesterol; D015032:Zinc; D013974:Thyroxine