Jan 5, 2007 (CIDRAP News) The US Department of Agriculture (USDA) yesterday proposed to reopen the US border to older Canadian cattle and beef for the first time since bovine spongiform encephalopathy (BSE) cropped up in Canada in 2003.
The USDA reopened the border to live Canadian cattle under 30 months of age in 2005, but the ban remained on older cattle and beef. BSE, or mad cow disease, is considered very unlikely to be found in cattle younger than 30 months because of its long incubation period.
Agency officials said a formal risk assessment indicates that if the prevalence of BSE in Canada declines orconsidered less likelystays the same over the next 20 years, the risk that BSE would enter and spread within the United States is negligible. Canada has had 8 BSE cases since May 2003, including 5 in 2006.
"For all commodities considered under the current proposal, the risk of BSE infectivity is negligible and the disease will not become established in the United States," said Dr. John Clifford, the USDA's chief veterinary officer, at a press conference. "This is true even if Canada identifies additional cases of BSE and even if an infected animal were to be imported into the United States."
Agriculture Secretary Mike Johanns commented in a news release, "We previously recognized Canada's comprehensive set of safeguards and we have now completed a risk assessment confirming that additional animals and products can be safely traded. Our approach is consistent with science-based international guidelines."
The USDA's proposed rule will be published Jan 9 in the Federal Register, and the agency will then take comments on it until Mar 12. Clifford said he couldn't predict how long it would take to digest the comments and implement the rule.
The rule would allow importation of live cattle born on or after Mar 1, 1999, effectively permitting cattle much older than 30 months. Meat from cattle of all ages would also be permitted, ending the current ban on meat from cattle older than 30 months, Clifford said.
In the USDA's estimation, the March 1999 date marks the start of effective enforcement of Canada's ban on putting cattle protein into cattle feed, a practice that is believed to spread the BSE agent, if present. Canada and the United States both imposed similar feed bans in August 1997. Clifford said the March 1999 date was picked to allow 6 months for implementation of the ban, plus another year for potentially contaminated feed to have passed through the system.
Besides ending the ban on older cattle and beef, the USDA is proposing to allow importation of Canadian cattle blood and blood products and part of the small intestine of cattle.
The USDA said it followed World Organization for Animal Health (OIE) guidelines in assessing the possible risks of lifting the ban on older Canadian cattle and meat. Clifford said officials estimated the prevalence of BSE in Canada to be 6.8 cases per 10 million adult cattle. The agency examined the risk in relation to all the BSE safeguards in place in Canada and the United States, including the ban on putting higher-risk cattle parts (specified risk materials, or SRM) into the food supply, he said.
Clifford said the risk assessment recognized that 3 of the 8 BSE-infected cattle found in Canada so far were born after March 1999, when the feed ban is considered to have been fully enforced. "These cases are not unexpected," and they don't change the USDA's conclusion about the enforcement date, he said.
The USDA risk assessment focused mainly on animal health, but one model was used to consider possible effects on human health, Clifford reported. "The results of this model indicated that these potential impacts are extremely low," he said. "Public health in the United States is protected through slaughter practices, including the removal of specified risk materials and the feed ban."
Jan 4 USDA news release
USDA risk assessment concerning proposal to allow importation of older Canadian cattle
Dec 30, 2004, CIDRAP News story "US to lift BSE-related ban on Canadian cattle"
Feb 10, 2005, CIDRAP News story "US to keep ban on meat from older Canadian cattle"