Consumer groups in the U.S. are demanding more comprehensive testing of beef after the government yesterday confirmed the second case of mad cow disease.
Meanwhile the meat industry is defending the existing safeguards.
The Department of Agriculture said it was still investigating where the infected beef cow, which was apparently at least 8 years old, came from.
In an attempt to reassure the public, agriculture secretary Mike Johanns said at a news conference, that the meat from the cow with the brain-wasting disease was not sold to consumers or as animal feed.
Johanns defended current safeguards as more than adequate to protect consumers, but did say the USDA would be changing some testing procedures.
Johanns insists that the threat of mad cow disease in the U.S. is so remote that there's a better chance of getting hurt crossing the street to get to the grocery store.
The announcement by the agriculture department was made a week before the fourth of July holiday which is traditionally one of the year's biggest days for beef consumption in the U.S.
Japan and Korea halted billions of dollars worth of American beef exports 18 months ago, when the first case of the deadly disease was reported.
Officials said that the infected animal was born before a 1997 ban on recycling cattle remains into cattle feed. The USDA, said there was no evidence the infected animal was imported, and was conducting DNA testing to confirm its herd of origin.
The previous US confirmed case of mad cow disease was found in December 2003 in a Washington state dairy cow imported from Canada.
Officials say that two confirmed infections was a very small number considering the 30 million cattle slaughtered annually in the United States.
Johanns says the presence of the disease is extremely low in the United States, and safeguards are working as they should.
Ron DeHaven, the head of the USDA Animal and Plant Health Inspection Service, says that the animal was found at a pet-food plant.
Neither official was prepared to identify the state where the animal came from, but several reports have said the infected cow was sent to slaughter last November in Texas, the nation's biggest cattle-raising state.
It is believed that mad cow disease is spread through infected livestock feed.
The second U.S. case first surfaced on June 10, when it was disclosed that the animal had tested positive for mad cow disease after initially returning inconclusive results.
Laboratories in Britain and the United States then conducted further tests.
After the first case was discovered, the USDA expanded its testing program to check more, but not all, sickly or ''downer" cattle.
Now consumer groups and some lawmakers are calling for tougher feed rules and mad-cow testing on all high-risk cattle.
Jean Halloran of Consumers Union, says they feel the authorities are continuing to drag their feet over the issue, as cattle blood still can be used as a feed supplement, and chicken litter and restaurant scraps, both of which could contain beef, can be used in cattle feed.
However Bob Stallman, president of the American Farm Bureau Federation, said the fact that both cases were found in animals born before the 1997 feed ban validates scientific knowledge of the disease, including how to contain it and how to prevent it.