Abstract:
In this on-farm investigation, we report on stillbirths, weakness and perinatal mortality seen
in calves on a commercial beef farm in the Roossenekal area, Mpumalanga province, South
Africa. Post-mortem examination of these calves and histopathological examination of organ
and tissue samples did not indicate an infectious aetiology. Affected calves had marginal to
deficient whole blood selenium concentrations. Whole blood samples collected from adult
cattle on this farm and five neighbouring farms were deficient in selenium. The potential
contributions of other minerals to the symptoms seen are a subject of ongoing investigation,
but selenium deficiency was marked in this herd and required urgent correction. Methods to
correct the deficiency included the use of injectable products, and an oral selenium supplement
chelated to methionine. Selenium availability to plants is primarily determined by the selenium
content of the parent bedrock, the presence of other minerals and the pH of the soil. The
apparent sudden onset of this problem implicates a soil factor as being responsible for reducing
selenium’s bioavailability in this area. Selenium deficiency can have a significant impact on
human health. HIV and/or AIDS, various forms of cancer and several specific clinical
syndromes are associated with selenium deficiency in humans, and the impact on human
health in this area also requires further investigation.
