WASHINGTON -- The Agriculture Department dramatically upgraded the country's defenses against mad cow disease Tuesday, banning meat from all so-called downer cows and promising to create a nationwide animal tracking system, steps long advocated by critics.

Interactive: Is Beef Risky? Still Confident In U.S. Beef? Mad Cow Q&A KIRO's Downer Cows Investigation Timeline USDA Info. World Cases WHO Fact Sheet Travel Info. How Mad Cow Disease Works

These are "very aggressive actions," Agriculture Secretary Ann Veneman said Tuesday, one week after the first case of mad cow disease surfaced on U.S. soil in a Washington state Holstein slaughtered on Dec. 9.

In 2002, KIRO Team 7 Investigators aired a series of reports that raised questions about the use of downer cows. See The Team 7 Investigation.

The changes will produce more rapid testing of cattle for the presence of mad cow disease, and meat will not be processed until test results are back.

Veneman also said small intestines from cows will no longer be allowed into the U.S. food supply, nor head and spinal tissue from cattle older than 30 months. In addition, the Bush administration is ordering changes in slaughterhouse techniques to prevent meat from being accidentally contaminated with brain or spinal cord tissue that can spread mad cow disease.

"Sound science continues to be our guide," Veneman said.

Many of the changes were implemented by Canada last May, when a single case of mad cow surfaced in Alberta. "We felt good about the system we had in place," said Dr. Ron DeHaven, the Agriculture Department's chief veterinarian.

Under the new U.S. regulations, the sick cow slaughtered in Washington state earlier this month would not have been allowed to enter the food chain.

The meat from that cow was allowed to be sold for human consumption after its brain and spinal column were removed and a federal inspector saw no indication of neurological disease. The Agriculture Department estimates that 130,000 down cattle are sent to meatpacking plants each year.

USDA ordered a recall of more than 10,000 pounds of meat from 20 cows slaughtered with the Holstein on Dec. 9. The recalled meat was distributed to eight states and Guam, although officials said 80 percent of it went to Oregon and Washington.

USDA officials have said they ordered the recall as a precaution, insisting there was no threat to the safety of the U.S. food supply. "The risk of BSE spreading in the U.S. is extremely low and any possible spread would have been reversed by the controls we have already put in place," Veneman said.

The other new measures include:

--Any animal tested for bovine spongiform encephalopathy (BSE) will not be allowed into the food supply until test results are confirmed. The Washington cow was sent to meatpacking plants almost two weeks before test results showed that it had mad cow disease.

--Prohibiting air injection stunning of cattle, a pre-slaughter practice that can disperse brain tissue.

--Stricter controls on automated carcass stripping systems to better insure that spinal cord tissue isn't nicked.

--Creation of a national animal identification that would enable officials to respond faster to an outbreak.

Veneman said the announced changes have been planned for a while. But they come just as U.S. agriculture officials in Tokyo are trying to persuade the Japanese to lift that country's ban on American beef. The U.S. officials went to South Korea after their stop in Japan.

"These actions are not being taken in response just to our trading partners," Veneman said. "We should take these actions that are appropriate and consistent with actions that many other countries have taken."

The agriculture secretary called the regulatory changes "very aggressive actions." She said they should not impose any hardship on the cattle and meatpacking industries, nor consumers.

"I don't expect an increase in the price to consumers," she said. "The number of cattle that enter the food supply currently as downer animals is very small."

Veneman acknowledged that banning downer animals from slaughter means they won't be tested for the presence of mad cow disease. She said officials are looking for other ways to test those at-risk animals but added that doesn't necessarily mean on-the-farm testing.

Gene Bauston, president of the New York-based animal rights group Farm Sanctuary, which has been suing the government for years to try to stop the use of downed animals for food, said the changes were huge.

"This is a good thing for animals and a good thing for people," said Bauston. "These animals are made to suffer horribly, humans are put at risk, and there has never been an excuse for this practice."

Democratic presidential candidates have seized on the mad cow emergency to criticize the Bush administration for policies they said have left the nation more vulnerable to such problems.

For Vermont Gov. Howard Dean said the administration shouldn't have objected to efforts in Congress to ban the slaughter of downed animals for meat nor resisting efforts to improve the system of tracking cattle. Dick Gephardt criticized the White House for siding with meatpackers against country-of-origin meat labeling as required under the 2002 farm bill, and ignoring the need for more federal money to inspect agricultural imports.