Scientists and ethicists debate 'gene editing' for animal health

In Iowa last spring, two dairy calves were born without horns, thanks to a rapidly growing but highly controversial practice called "gene editing." The startup Recombinetics created the calves by taking out the gene that makes dairy cows have horns and replacing it with a gene that renders Angus cows hornless. The procedure spared the calves a painful procedure called dehorning, which is done to protect farmers who handle dairy cows from getting hurt--and it ensured that future offspring of the two calves will be born hornless.

Many people who work in the food-production industry are enthusiastic about the potential for gene editing to improve the health of their animals, but some experts aren't so sure it's a good idea, according to a story in the New York Times. "Sometimes you can have nice benefits for animals and farmers and society but still have controversy among consumers," Jamie Jonker, vice president for sustainability and scientific affairs at the National Milk Producers Federation, told the Times. "I think dairy farmers are going to want to see how this is interpreted by the general public."

Gene editing has already grabbed headlines for the many ways it's being used in nonhealth applications. The FDA recently approved the first genetically modified salmon, for example, which has alterations that speed up its rate of growth. And legislators continue to debate whether crops that are genetically modified to resist pests should be labeled as such, even though they have been shown to be as safe as nonmodified foods.

Now researchers are using a variety of gene-editing tools, including one called CRISPR, to create all sorts of disease-resistant animals. The Roslin Institute in the U.K. has altered three genes in pigs to make them resistant to a devastating disease called African swine fever, according to the Times. And the National Science Foundation is funding research to create dairy cows that are resistant to sleeping sickness, a disease that's spread by parasites in Africa that must be treated with antibiotics.

Proponents of such projects say gene editing could help reduce the reliance on antibiotics in food production, which could not only help farmers comply with tough new rules intended to stop the spread of antibiotic-resistant illnesses, but might also make for more humane breeding practices. "If we know we can eliminate the disease and we don't, it is in my mind animal cruelty," said University of Maryland scientist Bhanu Telugu in the Times story.

But some scientists are using gene editing for nonhealth purposes--and that worries ethicists. Recombinetics has created a pig that grows fatter without the need for excessive feeding, as well as beef cows with large muscles that yield more tender meat. The explosion of this research led two academics to publish an essay on December 2 in the American Journal of Bioethics urging readers to think twice about gene editing.

The "widespread creation of such novel organisms should raise other concerns, particularly when they are not created for the purposes of saving lives, preventing climate change, feeding a growing humanity, or other valuable goals," they wrote in a paper whimsically titled "CRISPR Critters and CRISPR Cracks."

As for those two dairy calves born without horns, Lindsey Worden, the executive director for genetics at the Holstein Association, told the Times she hopes the public will ultimately accept the technique as a humane alternative to surgical dehorning. "We know there's a negative public perception of dehorning," she said, "and it's certainly not a fun chore for the farmers."

- here's the New York Times story (sub. req.)
- access the American Journal of Bioethics paper here

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