Washington ? The government is investigating a possible new case of mad cow disease but says there is no threat to the U.S. food supply.

Testing indicated the possible presence of the disease in a cow that died on the farm where it lived, John Clifford, the Agriculture Department’s chief veterinarian, said Wednesday. The animal was burned and buried, the department said.

“It is important to note that this animal poses no threat to our food supply because it did not enter the human food or animal feed chains,” Clifford said.

The cow probably was born in the United States and was at least 12 years old, Clifford said. He said that the cow had died of complications while giving birth.

The department knows the location of the farm but is not disclosing it, he said. There currently is no quarantine on the farm.

The department is conducting further tests at its laboratory in Ames, Iowa, and is sending tissue to be tested by the internationally recognized laboratory in Weybridge, England. Results should come in the next week, he said.

Two other cases of mad cow disease have been confirmed in the U.S. One was confirmed last month, in a Texas cow that died in November. The other was in a Canadian-born cow discovered in December 2003 in Washington state.

Clifford noted the animal in question was born before 1997, when the U.S. banned the practice of adding ground-up cattle remains to cattle feed. The only way cows are known to get the disease is by eating brain and nerve tissue of already-infected cows.

Of the 96 million U.S. cattle, the government has tested more than 419,000 for mad cow disease.