Investigators search for mad cow source

INVESTIGATORS are combing Canadian feed mills and rendering plants to try to pinpoint the source of infection for the BSE-infected Washington state cow.

Meanwhile, US officials trying to contain the outbreak of the disease said a Washington state farm already under quarantine was also home to nine other cows that entered the United States from Canada in 2001 with the infected Holstein. The Mabton farm was the diseased cow’s final home and also had one of its calves.

Mad cow disease is a concern because humans can develop a brain-wasting illness, variant Creutzfeldt-Jakob disease, from consuming infected beef products. The US Centres for Disease Control and Prevention said 153 people worldwide, most of them in Britain, had contracted the human form of the illness since the mid-1990s.

Another priority in the investigation is locating the source of infection. Canadian investigators are considering whether an Alberta rendering plant could have been the source of contaminated feed that infected the Washington cow and, perhaps, the Canadian cow.

Records indicate both cows were born in western Canada in the spring of 1997, a few months before the United States and Canada banned the practice of including parts of cattle and other cud-chewing animals in cattle feed. Genetic testing that would confirm the accuracy of the records is to take place.

Such a link could solve the mystery of how the first US case of the disease occurred. It would also go a long way toward calming the fears of some two dozen nations that have halted

2.5 billion in annual shipments of American beef, according to experts. The diagnosis of mad cow disease in an animal in rural Washington state last week sent cattle prices skidding by nearly 20% and forced the administration of George W Bush to ban the use of sick or crippled cattle in human food, a measure long opposed by the meat industry. Consumer groups and some Democrats have expressed scepticism about whether that and related regulatory changes go far enough.

US Agriculture Department investigators hope to complete DNA testing early next week to confirm their suspicions that the infected Holstein cow was born in Alberta, Canada, in April 1997. Canada reported its first case of mad cow disease earlier this year in a Black Angus cow, also from Alberta.

While the USDA investigation into the cause of the mad cow case continues, the Bush administration is trying to restore the confidence of international meat buyers.

American officials will fly to Mexico City next Tuesday to urge Mexico to reopen its border to American beef. Officials will discuss what the United States is doing to control the disease, said Javier Trujillo, head of the Mexican agriculture ministry’s animal health commission.

Earlier this week, an American trade delegation visited Tokyo and Seoul to urge both nations to allow beef exports to resume.

The National Cattlemen’s Beef Association and the American Meat Institute want the White House to make resumption of beef exports a top trade priority.

Another problem for exporters is the fate of 44,000 tonnes of American beef, valued at 280 million, that was in transit to other countries at the time the first case of mad cow was discovered. All the meat is in limbo due to the trade bans.