[Selenium content in blood of cattle in the Weser-Ems region and effects of Se fertilization of pasture grounds on Se levels in growth and in blood dairy cattle with extreme selenium deficiency].

The evaluation of 1.974 selenium levels in samples of bovine blood mainly from the Weser-Ems region showed a high rate of selenium deficiency in calves, young cattle and heifers ante partum. More than 50% of cows showed Se deficiency, too. After fertilizing of pasture grounds exhibiting extreme selenium deficiency with 35 g of selenium per hectare, the authors found significantly positive effects on plant selenium levels and in blood of grazing young cattle. At the same time, the selenium contents in blood of the control animals decreased extremely as the result from being cut off from the selenium supply in the young stock shed during winter time.