A US appeals court is hearing arguments today in the latest bid by an American ranchers group to restrict all Canadian cattle imports.

The case has been launched by the Ranchers-Cattlemen Action Legal Fund and dates back years.

The Montana-based group's legal fight was successful in delaying the resumption of the beef trade after Canada's first mad cow case in May 2003, prolonging a crisis that has cost Canadian ranchers
billions.

The group argues Canadian imports are unsafe and US officials are endangering the food supply.