Mad cow disease is found in US

America's multi- billion dollar cattle industry is reeling today after the discovery of the country's first case of mad cow disease.

A single Holstein cow diagnosed as suffering from BSE could spell disaster for the £17billion industry. Japan, the biggest market for American beef, and South Korea today banned US imports.

Beef industry shares are expected to plummet today as markets open for the last time before the Christmas break. McDonald's saw more than a dollar wiped from its share price in overnight trading.

Agriculture department officials confirmed last night that a cow slaughtered this month had tested positive for BSE.

Officials said the infected beef did not reach the food supply, while the rest of the herd has been quarantined and is likely to be slaughtered.

"There is no risk to consumers based on the product from this animal," said Terry Stokes, chief executive of the National Cattlemen's Beef Association.

US agricultural secretary Ann Veneman called the risk "minimal", adding: "We will take all appropriate actions out of an abundance of caution."

In an echo of remarks by Tory agricultural minister John Gummer, she said: "I plan to serve beef for my Christmas dinner."

The diseased cow was found unable to move on a farm in Mabton, Washington, and tested positive on 9 December. Infected parts, including the spinal cord and brain, were removed before the meat was sent to a processing plant.

US authorities have banned beef from countries where BSE is found - most recently, Canada earlier this year.

There are fears a version of mad cow disease found in wild elk herds in the US may now have jumped species.