“People should stop consuming dairy or meat or eggs, not further manipulate animals by playing with their DNA,” Mr. Byer added. The Food and Drug Administration has not said how or whether it will regulate the gene-edited animals to come. But even with the government’s stamp of approval, biotechnology advocates know that farmers are unlikely to embrace technology if they fear consumers will reject it. And it has not helped the popularity of genetically engineered crops that their chief benefits so far — easier control of weeds and pests for corn and soybean farmers — are not terribly compelling to the eating public. That is one reason Recombinetics has begun to show off its hornless calves. Dehorning, which involves burning off horn-buds to stop the flow of blood to the horn tissue, has already garnered a degree of popular concern. Videos of the burning procedure carried out on Holsteins, the black-and-white breed largely responsible for the nation’s milk supply, and circulated by animal rights groups, draw long strings of critical comments. “We know there’s a negative public perception of dehorning, and it’s certainly not a fun chore for the farmers,” said Lindsey Worden, the executive director for genetics at the Holstein Association. A small fraction of Holsteins are naturally hornless, and several companies, including General Mills, Dannon and Walmart, have encouraged their dairy suppliers to increase their population through conventional breeding. Farmers have made some headway, with the population of hornless Holsteins climbing to about 4 percent last year from 3 percent in 2013. But it is slow going. That is why several dairy breeders say they are keeping tabs on Recombinetics’ two hornless calves, which have just been shipped to the University of California, Davis, to be monitored for their health. There, in a few months, their sperm will be harvested, each with edited DNA, which will be used to create a new generation of hornless cattle.
With the recent FDA approval of genetically engineered salmon as safe for human consumption , the gene - editing technology industry has been given a massive boost , despite ethical reservations . The new techniques have reduced the cost and increased the ease of genetically engineering DNA , leading to positive breakthroughs including disease - proof pigs and swine fever resistant pigs . Also in development are breeding animals for the food chain , including gene - edited pigs that can be fattened with less food , and more tender and meat - yielding Brazilian beef cattle . However , with no stated regulation from the FDA , public perceptions and approval may be the deciding factor whether the gene - editing technology reaches its potential as farmers will be wary of consumer rejection .