The proposal expands upon a rule published by the USDA's Animal and Plant Health Inspection Service (APHIS) in January 2005 that allowed for the import of certain live animals and animal products, including cattle under 30 months of age, from countries recognized as minimal-risk.
In the rule announced last week, APHIS is proposing to allow the importation of live cattle and other bovines for any use born after March 1 1999.
"This proposal would continue to protect against BSE in the United States while taking the next step forward in our efforts to implement science-based trade relations with countries that have appropriate safeguards in place to prevent BSE," said Agriculture Secretary Mike Johanns.
Currently, Canada is the only minimal-risk country designated by the United States.
"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," said Johanns.
But Canada's meat industry was hit in recent years by a spat of disease scares and import bans that crippled production. In 2003, the US closed its borders to Canadian beef after the discovery of bovine spongiform encephalopathy (BSE) in a Canadian cow.
Even though the US resumed live imports of Canadian cattle in 2005, beef supplies from Canada to the US are still 20 per cent below the 148,552 metric tons sent across the border prior to 2003, according to a USDA report released last year.
As part of the latest APHIS proposal, the agency conducted a risk assessment following guidelines put forth by the World Organization for Animal Health, or OIE. This found little risk associated with meat and meat products from countries recognized as 'minimal risk'.
"This assessment evaluated the entire risk pathway, including mitigations in place both in Canada and the United States. The assessment included evaluating the likelihood of introduction of BSE via imports, the likelihood of animal exposure if this were to occur and the subsequent consequences. All of these were combined to give the overall minimal risk estimation," said the USDA in a statement.
"It is important to note that BSE transmission is prevented in bovines by a series of safeguards, including; slaughter controls and dead animal disposal, rendering inactivation, feed manufacturing and use controls, and biologic limitations to susceptibility. These layers of protection work together to prevent spread of the disease," it added.
BSE or mad cow disease can lead to its variant, Creutzfeldt-Jakob Disease (vCJD), in humans. It is spread by prions, abnormally shaped proteins that originate in the neurological tissues.
BSE spreads by consumption of feed that has been contaminated by prions. The human form of the disease can be transmitted if a human being eats BSE infected meat, and through blood transfusions.
Consuming meat from infected cattle has led to the deaths of 154 people worldwide from vCJD.
The proposed rule by APHIS is currently open to comments, which must be received by March 12 2007.