Study of the bioavailability of selenium in cows' milk after a supplementation of cow feed with different forms of selenium.
The purpose of the work described in this paper was to develop an easy and quick in-vitro method for comparing the bioavailability of selenium in cows' milk after different cow feed. The study focuses on bioavailability differences resulting from the use of different selenium species (organic selenium as selenised yeast and sodium selenite) for supplementation of forage. A procedure for determination of selenium in cows' milk and dialysates, by hydride-generation atomic-fluorescence spectrometry (HG-AFS) after microwave-assisted acid digestion, was optimised. The results show it is possible to obtain cows' milk enriched with selenium at different concentration without altering the original composition of the milk. The bioavailability was statistically greater for cows' milk obtained after supplementation of forage with organic selenium at levels of 0.4 and 0.5 microg Se g(-1) than for that obtained after supplementation with inorganic and organic selenium at levels of 0.2 and 0.3 microg Se g(-1).
Muñiz-Naveiro
Oscar
O
Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avda. de las Ciencias, s/n, 15782 Santiago de Compostela, Spain.
Domínguez-González
Raquel
R
Bermejo-Barrera
Adela
A
Bermejo-Barrera
Pilar
P
Cocho
José A
JA
Fraga
José M
JM
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001682:Biological Availability; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D005527:Food, Fortified / Q000032:analysis; D008892:Milk / Q000737:chemistry*; D012643:Selenium / Q000008:administration & dosage / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics*
D012643:Selenium