"Through the past two years, I have listened carefully to stakeholders throughout the country about how to reach effective animal disease traceability in a transparent manner without additional burden," said Agriculture Secretary Tom Vilsack.

"We are proposing a flexible approach in which states and tribes can develop systems for tracing animals that work best for them and for producers in their jurisdiction. This approach offers great flexibility at the state and local level and addresses gaps in our disease response efforts."

Under the proposed rule, unless specifically exempted, livestock moved interstate would have to be officially identified and accompanied by an interstate certificate of veterinary inspection or other documentation, such as owner-shipper statements or brand certificates.

The proposed rule encourages the use of low-cost technology and specifies approved forms of official identification for each species, such as metal eartags for cattle. However, recognising the importance and prevalence of other identifications in certain regions, shipping and receiving states or tribes are permitted to agree upon alternative forms of identification such as brands or tattoos.

"Our proposal strives to meet the diverse needs of the animal agriculture industry and our State and tribal partners, while also helping us all reach our goal of increased animal disease traceability," said chief veterinary officer for the US, Dr John Clifford.

"We believe reaching our goals on traceability will help save the industry and American taxpayer's money in the long term."

According to the National Chicken Council, the poultry industry is largely exempted because the existing system for poultry is more comprehensive than in the cattle industry.

Poultry flocks being moved across state lines directly to slaughter will not come under the new requirements, APHIS said, nor will birds being sent to diagnostic facilities, or flocks participating in the National Poultry Improvement Programs (NPIP). The agency said NPIP and other programmes 'provide USDA and its partners with pertinent traceability information'.