Gene-edited cattle produce no horns
Cornell Alliance for Science

Gene-edited cattle produce no horns

Nearly 80% of U.S. dairy cows have their horns removed each year to protect their handlers and fellow cattle. But the practice, which is both painful and expensive, has come under increasing scrutiny from animal rights activists. Now, science may be coming to the rescue: A group of researchers announced last week that they successfully edited the genomes of dairy cows to make them hornless. The scientists used the transcription activatorlike effector nucleases DNA editing technique to introduce a natural allele linked to hornlessness into dairy cow embryos. Five healthy calves were born, all without horns (including 2-month-old Spotigy, above), the researchers report in a letter in Nature Biotechnology. The allele—called POLLED—is much more common in beef cattle than dairy cows; as a result, just 25% of beef cattle have to go through the painful process of dehorning. But naturally introducing the gene into a population would take decades, so scientists hope their technique can become a cheaper and quicker alternative.