Scotland's government says a case of bovine spongiform encephalopathy (BSE), or mad cow disease, had been discovered on a farm in Aberdeenshire, in Scotland.
The disease was discovered after the animal died.
Four others in the herd were destroyed as a precaution.
The government said other precautionary movement restrictions have been put in place at the farm, while further investigations are carried out to identify the origin of the disease.