A herd of cows blandly chewing their cud in a grassy field seems like an unlikely source of danger, but the pastoral scene apparently has a dark side, so scientists are now trying to genetically engineer some hornless dairy cows.
According to the Daily Mail, removing the horns from dairy cows would cut back on the risk of injury to farmers and other animals. Farmers currently burn off the horn buds of baby cows to prevent horns from developing, but the process is unpleasant and painful for the animals. Farmers were previously able to get rid of the horns on some varieties of beef cattle through selective breeding, but have been unable to do the same for dairy cows without affecting the milk supply.
Instead, scientists are going to take a crack at it. Researchers plan to achieve hornless Holsteins, the highest-producing breed of dairy cow, by taking a bit of DNA that is known to stop horn growth from other breeds of cattle and editing it into the Holstein genome.
Scott Fahrenkrug, professor of genetics at the University of Minnesota, has already taken the horn-suppressing DNA and edited it into cells taken from a Holstein bull named Randy. Next, those cells will be turned into 40 embryos and implanted into a herd of female Holsteins. One gestation period later, those cows will give birth to little clones of Randy that don't have horns. The offspring of the hornless Randy clones will also be hornlesss. The scientists say the process will not have any effect on the milk the new cows will produce, because aside from the missing horns they will be just like regular Holstein cows.