Erythrocyte glutathione peroxidase activity as an indicator of selenium status in an intensively-managed beef herd

A survey of erythrocyte glutathione peroxidase (GPx) activity was undertaken in a herd of crossbred cattle after 3 cases of white muscle disease had been diagnosed. All animals examined, appeared to be deficient in selenium, relative to control animals sampled. Oral administration of sodium selenite or sodium biselenite was followed within 30 d by an increase in erythrocyte GPx activity. Despite an apparent improvement in the selenium status of cows after supplementation with selenium, no difference was seen in the conception rate after artificial insemination.