Selenium content and distribution in cow's milk supplemented with two dietary selenium sources.
The effect of two sources of Se, selenized yeast (Se-Y) and sodium selenite, added to total mixed rations (TMR) fed to cows on Se milk content and distribution in milk components was studied on three farms for 6 weeks. The maximal increase in milk Se was attained with Se-Y supplemented at 0.3 microg g(-1). The effect was immediate, with an increase of 9 microg L(-1) being observed after only 5 days, and remained steady until the last sample at day 40 of Se supplementation. Se distribution in milk components was constant, 53.6, 42.6, and 9.3% in whey, casein, and fat, respectively, and was unaffected by the form of supplementation. The effect of the level of Se-Y supplementation on milk Se was studied on two farms. Increasing dietary Se-Y from 0 to 0.5 microg g(-1) elevated milk Se content from 20 to 39 microg L(-1). Se-enriched cow's milk at different levels can be produced by varying dietary Se supplementation in the form of selenized yeast.
Muñiz-Naveiro
Oscar
O
Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida de las Ciencias s/n, E-15782 Santiago de Compostela, Spain.
Domínguez-González
Raquel
R
Bermejo-Barrera
Adela
A
Cocho de Juan
José A
JA
Fraga Bermúdez
José M
JM
Goris Pereiras
Alfonso
A
López Santamariña
Antonio
A
Martínez Lede
Ismael
I
Valledor Puente
Javier
J
Fernández-Couto Gómez
Luis
L
Bermejo-Barrera
Pilar
P
D000818:Animals; D002417:Cattle; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D008892:Milk / Q000737:chemistry*; D012441:Saccharomyces cerevisiae; D012643:Selenium / Q000008:administration & dosage* / Q000032:analysis*; D012645:Selenomethionine / Q000032:analysis
D012645:Selenomethionine; D012643:Selenium