Two cows meet at a fence. “This mad-cow disease sure is scary,” says the first. “I know what you mean,” replies the second. “Good thing it doesn’t hurt us chickens.”

Maybe you’ve seen that joke on the Internet. In truth, mad-cow disease is no laughing matter because it may cause death in humans who have suffered the rare misfortune of eating tainted meat.

That’s the bad news. The good news is that biotechnology is on the verge of a solution.

Newspapers rang in the New Year with stories of a major breakthrough. “Scientists said yesterday that they have used genetic engineering techniques to produce the first cattle that may be biologically incapable of getting mad cow disease,” explained the Washington Post.

Cattle that carry what’s formally known as bovine spongiform encephalopathy (BSE) produce proteins called prions. Prions that go bad may be a root cause of a deadly brain disorder in humans called Creutzfeldt-Jakob disease.

Scientists at a South Dakota company appear to have figured out how to suppress a gene that allows cattle to produce prions. “This is a seminal research paper,” said Barbara Glenn of the Biotechnology Industry Organization. “This shows the application of transgenics to improving livestock production and ultimately food production.”

In the United States, BSE is quite rare: The Department of Agriculture recently described its incidence as “extremely low” and reported that “the most likely number of cases is between 4 and 7 out of 42 million adult cattle.” By contrast, there were thousands of confirmed cases in Europe, particularly in the UK, before adequate regulatory measures brought that problem under control.

These numbers prove that U.S. regulators are already doing an excellent job of protecting Americans from the outbreaks that have afflicted other countries. Yet our goal should be nothing less than the complete elimination of BSE from the food chain.

This is important not only for our physical health, but also our economic well-being. When the first reports of BSE in the United States surfaced in the final days of 2003, several nations closed their markets to our producers. Japan’s remained shut until last July–a total of two and a half years. Americans suffered billions in financial losses.

Even now, significant import restrictions remain in place. Japanese restaurants and consumers have started to complain because the demand for American beef is outstripping the supply. Japan itself has discovered many cases of BSE in Japanese herds and is struggling to manage their own problem. Today, biotechnology is showing promise for restoring Asian confidence in beef products.

Key questions remain. Prions aren’t well understood. Some researchers believe that they may contribute to normal growth in ordinary organisms. Can a cow survive without even a single one of them?

Scientists are hopeful because so far they’ve produced a dozen cattle without prions. These animals are now approaching their second birthday. “By our analysis–how do they eat, how is their heart rate, how is their immunological function–they seem to be normal,” said one USDA expert who is studying them.

The only way they’re abnormal, it would seem, is that they can’t contract BSE. This abnormality isn’t a defect, but an improvement: It means that they can’t pass the disease on to humans.

We’re still a long way from building entire herds of cattle without prions. An enormous amount of research remains to be done. The first commercial uses of prion-free cattle probably won’t involve food, but rather pharmaceutical products. This will take plenty of time, too.

The bottom line is that we’re on the cusp of remarkable developments in food production, thanks to biotechnology. Very recently, the Food and Drug Administration concluded after intensive study that milk and meat from cloned animals do not pose any unique health risks to people who consume them.

This advancement is typical of the reach and potential of biotechnology. This sort of research and the application of important breakthroughs tend to run quietly in the background of people’s lives. US consumers expect the extraordinarily safe food that is available in this country. Technology just moved food safety forward a bit more.

Thankfully, it doesn’t take a Ph.D. in molecular biology to appreciate how the eradication of BSE can help consumers. Heck, even a cow who thinks she’s a chicken can understand that.

Dean Kleckner, an Iowa farmer, chairs Truth About Trade & Technology (www.truthabouttrade.org)