Cows Engineered for Immunity to Mad Cow Disease

Scientists have created a dozen cattle that seem to be immune to mad cow disease. The animals, now 2 years old, have been genetically engineered to lack the protein that's susceptible to the disease.

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RENEE MONTAGNE, host:

One of the biggest threats to the beef industry is mad cow disease. It's only been found in three cows in the United States. It causes brain damage and death, and in rare cases it can infect people. Concerns about mad cow nearly ruined the beef industry in Great Britain. Now scientists have made cows that seem to be immune.

NPR's Nell Boyce reports.

NELL BOYCE: James Robel(ph) grew up in a farm in central Kansas.

Mr. JAMES ROBEL (Biologist, Hemotech): We have one dairy cow that I milked every morning and every night. So I grew up working with cows, and I worked with cows ever since.

BOYCE: These days he's not after milk. Robel is a biologist at a company called Hemotech in South Dakota. It's in the business of genetically altering cows so that they make pharmaceuticals in their milk or blood.

Mr. ROBEL: We were embarking on a path to use the cow as a production system for something that people would inject into their veins.

BOYCE: Their products would have to be absolutely free of cow diseases, like mad cow, also known as Bovine Spongiform Encephalopathy, or BSE. So they turn to genetic engineering for a solution. Robel knew that this disease targets a particular protein in the brain. What if he made cows that simply didn't have this protein? He could do this by disabling or knocking out the gene for the protein.

Mr. ROBEL: The challenges I guess started right in the beginning. Nobody has been able to knockout a gene in a cow.

BOYCE: Until now. Robel and his colleagues spent years working with cow cells and embryos. Now they've published a report in the journal “Nature Biotechnology”. They made a dozen calves - all lack the brain protein.

Mr. ROBEL: They are cute animals when they're born, particularly the Holstein Jerseys. They have these nice big sad eyes.

BOYCE: So far, the two-year-old cows seem perfectly healthy. And in lab tests their brain tissues seem to resist the infectious agent that causes mad cow. A few of the cows have now been exposed to the agent. They'll be watched for several years to see if they develop the disease. Some experts seriously doubt that dinner plates soon will feature mad-cow-resistant stakes. James Hodges is president of the American Meat Institute Foundation.

Mr. JAMES HODGES (President, American Meat Institute Foundation): As a research model, I think it's positive development. But the impact on the industry will probably be quite minimal in the short term. You're not going to replace the entire cattle herd at the United States.

BOYCE: Hodges says even if the industry wanted to introduce these cows, they couldn't. The Food and Drug Administration recently said it's safe to eat cloned cows, pigs and goats, but the agency has not issued an opinion on the safety of animals with genes that have been altered in the lab. George Sidel is a livestock expert at Colorado State University. He says no one knows if any person who has gotten mad cow after eating beef raised in this country…

Professor GEORGE SEIDEL (Biomedical Science, Colorado State University): But theoretically, if there were a problem, the animals without this gene couldn't get the disease or transmit it.

BOYCE: And he says that may be attractive to people who worry about getting mad cow from eating beef.

Prof. SEIDEL: In some cultures, some situations, people may be willing to pay a premium for animals that can't possibly have that problem.

BOYCE: That isn't a market that Hemotech plans to pursue, even though James Robel says he personally wouldn't mind eating this kind of gene-altered beef.

Prof. ROBEL: I wouldn't have any problem with eating clones. I don't really have any problems with eating a genetically modified animal.

BOYCE: But he says he's not worried about getting mad cow, so he wouldn't pay any extra money for it.

Nell Boyce, NPR News.

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