Isolation of Ehrlichia risticii, the causative agent of Potomac horse fever, from the fetus of an experimentally infected mare

Abstract

TWELVE crossbred Hereford calves were divided into two groups and fed concentrate diets containing either 0•2 per cent or 0•75 per cent sulphur, with free access to hay and water for 85 days. There were no significant differences between the groups in terms of the activities of the enzymes glutathione peroxidase, glucose-6-phosphate dehydrogenase and acetyl cholinesterase or plasma aspartate aminotransferase, nor in blood selenium concentrations, bodyweight gains or clinical health. The results show that moderate increases in dietary sulphur concentration should not impair selenium or copper metabolism or cause related disorders in cattle.