The U.S. Agriculture Department, or USDA, announced this week a plan for a tenfold increase in testing for mad cow disease. Cattle producers in the United States have generally praised the plan as a way of shoring up consumer confidence domestically and in countries that import U.S. beef products. But some consumer advocates think the USDA plan is inadequate.

Under the plan announced Monday by U.S. Agriculture Secretary Ann Veneman, starting June first, tests will be performed on half of the 446,000 cows that are designated as downers. These are cattle that show some sign of possible nervous system disorders, such as inability to walk properly. An additional 20,000 apparently healthy cows will be tested for mad cow disease before being slaughtered.

Scientists working with the USDA say this sampling will determine if there is, in fact, any sign of the disease, known technically as bovine spongiform encephalopathy. If even a few cases are found, then there would be reason for more far-reaching tests.

Bert Rutherford, spokesman for the Texas Cattle Feeders Association, says this is a reasonable way to proceed. "It is a good idea because it will give us some answers to some questions," he says. "It will give us a benchmark which we can use to look at how we are approaching the disease, what we are doing to keep it out, those sorts of things, and approach that in a much more scientific manner."

But representatives of several consumer groups and a number of foreign governments have expressed skepticism. Diane Farsetta is research director for the Wisconsin-based Center for Media and Democracy, a non-profit organization that examines public policy issues. "The interest of the cattle industry is being considered much more than public health interests right now," she says.

Ms. Farsetta says the USDA testing plan does not go far enough and ignores some of the advice provided by a panel of international experts. "The international panel came out saying that just looking at the practices by the cattle industry and the lack of testing so far that there is very likely mad cow disease in the United States and that there might be new cases every month and that the USDA should be addressing this with a sense of urgency and really criticized how the United States has been handling it so far."

She says focusing mainly on the downer cattle is an inadequate approach if public health is the priority. She notes that some cattle found with the disease in Europe and Asia did not fit the profile being used by the USDA testing program.

"If you look at other countries, Japan, for example, which screens every cow-all of the cows that they have found to be positive for mad cow disease have seemed apparently healthy," says Ms. Farsetta. "So, we feel it is important to be testing much more, many more of the cows that are actually going into the human food supply."

But USDA officials and cattle industry representatives say testing every one of the nation's 45 million cows before they go to the slaughter house would be unreasonably expensive and time-consuming.

The Texas Cattle Feeders Association's Bert Rutherford says testing every cow at the slaughterhouse gate would not make the nation's food supply any safer. "I think it is very unrealistic and not at all scientifically based. The reason for that is, looking particularly at the experience in Europe, you just do not see it beginning to manifest itself at all in cattle under 30 months of age," he says. "So testing cattle under 30 months of age would be a lot like a doctor deciding he is going to test all of his patients for prostate cancer, including the women."

Mr. Rutherford says consumers have backed the government and the cattle industry on this issue so far. He says there was a brief drop in beef consumption following the discovery of a cow in Washington state with Mad Cow disease back in December, but that most Americans went back to eating their steaks and hamburgers after being assured that this was an isolated case.

"Consumers have not backed up a bit," says Mr. Rutherford. "They responded initially to the media reports, understood fully that the risk is essentially zero for humans and so consumer demand for beef has remained very strong since December 23."

But some scientists studying the problem say the public could be at risk if there are any undiagnosed cases of the disease out there in the pastures and feed lots and the government testing plan fails to find them. While not all critics say that every cow should be tested, many of them do suggest that the sample be greatly increased in order to prevent any possibility of the degenerative disease affecting the human population.