WASHINGTON — The U.S. Department of Agriculture plans to expand its ban on the use of beef from cattle that cannot stand or walk, citing continued worries about mad cow disease.

The USDA's latest proposal would end the practice of a case-by-case review of cattle that become non-ambulatory after initial inspection. Officials posted the measure for public comment until Sept. 29.

Friday's proposal won praise from the National Milk Producers Federation, which had urged the Bush administration to end any doubt about cows headed to slaughter by implementing a more consistent rule.

"This proposed rule accomplished exactly what our groups requested," said NMPF Chief Executive Officer Jerome Kozak in a statement. The National Meat Association and the American Meat Institute had joined the NMPF in urging a broader ban.

If the proposal becomes final, federal inspectors will no longer have the authority to approve cattle that become unable to walk or stand after arriving at the slaughter facility. All such cattle would be immediately condemned and removed from the supply for human consumption.

"To maintain consumer confidence in the food supply, eliminate further misunderstanding of the rule and, ultimately, to make a positive impact on the humane handling of cattle, I believe it is sound policy to simplify this matter by initiating a complete ban on the slaughter of downer cattle," said Agriculture Secretary Ed Schafer in a press release.

The prohibition on so-called "downer" cattle is tied to mad cow disease, or bovine spongiform encephalopathy, a brain-wasting illness. It is related to a similar disease in humans that can be contracted through consumption of contaminated meat.

One of the symptoms of mad cow disease is an inability to stand or walk.

The ban on downer cows, however, has been debated in the farm community because cows can become non-ambulatory for many reasons unrelated to mad cow disease. The jostling typical to herds of large animals, perhaps on the way to slaughter, is one example farmers cite.

But the USDA, in its announcement, said instances of cattle becoming injured after an initial USDA inspection are rare. Veterinarians approved fewer than 1,000 such cattle for slaughter in 2007, out of 34 million slaughtered, the department reported.

With the new regulation, plants would be required to report all cattle that become non-ambulatory after passing an initial inspection.