A Texas cow has tested positive for bovine spongiform encephalopathy (BSE, Mad Cow Disease), the U.S. Department of Agriculture reported.

Last fall, the animal was given a clean bill of health, but after it died in November, a second test for the brain-wasting Mad Cow Disease came back with a "weak positive," USDA secretary Mike Johanns said at a news conference.

Another sample will be sent to the world's top BSE lab in Weybridge, England, for a final test, the Washington Post reported.

Johanns stressed people do not face any greater health risk from eating beef, because meat from the animal did not enter the human food chain or the beef feed chain.

While the first U.S. Mad Cow Case in 2003 involved an animal born and raised largely in Canada and then shipped to Washington state, USDA chief veterinarian John Clifford said the agency had no information that the possible second case was "an imported animal."

Taiwan will halt the import of U.S. beef if the second case of Mad Cow Disease in the U.S. is confirmed, a health official said.

"The U.S. has sent samples to Britain for further test. If the test result is positive, we will immediately suspend U.S. beef imports," Chen Lu-hung, head of the Department of Food Safety under the Department of Health, told reporters.

However, Chen assured consumers in Taiwan that the U.S. cow suspected of carrying BSE was isolated as soon as it showed difficulty in walking, so the questionable beef has not entered the U.S. market, let alone the Taiwan market.

Taiwan halted U.S. beef imports in December 2003 after the U.S. reported its first case of Mad Cow Disease but lifted the ban last April 16, after Taiwan health officials inspected the safety measures in U.S. slaughterhouses.

Taiwan now allows the import of boneless beef cuts from U.S. cattle younger than 30 months. However, cattle parts such as intestines and tonsils, which have a higher risk of being contaminated, are still prohibited.

No word was available on the impact of the discovery among other trading partners, nor on the ramifications among negotiators attempting to reopen certain markets in Asia to American beef.