Genome editing opens possibilities for genetically modified livestock

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Beef cattle graze off the Flint Hills on Sept. 26, 2014. (Rodney Dimick | The Collegian)

Scientists said they believe they are on the cusp of developing new strains of livestock using DNA technology that may improve meat and milk production while alleviating consumer fears, according to an MIT Technology Review article published in September.

A June poll by ABC News found that “barely more than a third of the public believes that genetically modified foods are safe to eat,” yet a consensus among scientists and industry professionals alike said the exact opposite.

While there is controversy surrounding genetically modified organisms, most concerns center around genetically modified plants, developed by splicing specific DNA from one plant species into another. Scientists are developing a new technology called genome editing they believe will revitalize the concept of genetically modified livestock since the process involves genes in animals that are currently in the food supply.

Jennifer Bormann, associate professor of animal breeding and genetics, said using this technology can improve cattle quality without changing the quality of meat or milk consumers get from the animal.

“When changing one specific gene, all other genes are unaffected,” Bormann said. “It would be possible to change a gene that affects meat or milk. If, for example, you wanted to make the meat more tender, you might change a gene that has been proven to make meat tender.”

She also said the genome editing technology doesn’t create any food safety concerns because, “we have been doing it for a long time in plants,” and the same product could be created without the use of this technology.

“We could do the same thing with traditional breeding by crossing and backcrossing repeatedly to introgress the gene of interest,” Bormann said. “It would just take many generations of crossing and many years.”

Karen Batra, director of food and agriculture communications for the Biotechnology Industry Organization, said genetic engineering is the deliberate modification of the animal’s genome using techniques of modern biotechnology.

“Many might be surprised to know that genetically engineered animals are just like ‘normal’ cows, pigs, goats and fish – only better,” Batra said. “They all contain a specific gene that makes them better than their conventional counterparts.”

Batra also said that by incorporating genes from other organisms in a process called transgenesis, genetically engineered animals are being developed to address five broad goals. The goals are to advance human health, enhance food production and quality, mitigate environmental impact, optimize animal welfare and improve industrial products.

Scott Fahrenkrug, a molecular geneticist and CEO of Recombinetics, said in the same MIT Technology Review article that he can create cattle with traits not normally found in their DNA, such as hornless dairy cattle, that will improve animal welfare by eliminating manual dehorning and increase safety for both animals and farmers. He said this can be achieved through genome editing, the precise modification of the nucleotide sequence of the genome. In other words, it’s a quick and accurate new way to alter DNA in animals.

The Food and Drug Administration has never before approved a GMO food animal, but some hope this new technology could increase the public’s acceptance and encourage federal approval.

Fahrenkrug said gene editing shouldn’t be regulated if it’s used to merely to swap around traits within a species.

“We’re talking about genes that already exist in a species we already eat,” Fahrenkrug said.

To date, no genetically engineered animal foods are available to the public, but the FDA recognizes the potential of such technology. A fact sheet released by the FDA in May suggests genetically engineered animals could help increase global food production.

“(Genetically Engineered) animals with new traits for disease resistance, or drought and heat tolerance, may allow for high quality food to be produced in parts of the world where disease, climate or accessibility of forage material have previously limited the ability to raise food animals,” the FDA said in the sheet.

The regulatory agency must approve any genetically modified animal foods.

“Only food from GE animals that is safe to eat will be permitted into the food supply,” the FDA said.

While genetically engineered animals are not available in production agriculture, the vast majority of livestock feeds contain GMO ingredients. While the safety of those GMO ingredients has been questioned by some, John Entine, wrote for Forbes that “The debate about GMO safety is over, thanks to a new trillion meal study.”

Entine, also executive director of the Genetic Literacy Project, referred to the Journal of Animal Science published study by University of California-Davis Department of Animal Science geneticist Alison Van Eenennaam, and research assistant Amy E. Young. They reviewed 29 years of livestock productivity and health data from both before and after the introduction of genetically engineered animal feed. In what was called the most comprehensive study of GMOs and food ever conducted, they found the use of the technology was safe.

“The field data represented more than 100 billion animals covering a period before 1996 when animal feed was 100 percent non-GMO, and after its introduction when it jumped to 90 percent and more,” Entine wrote in the study. “The documentation included the records of animals examined pre and post mortem, as ill cattle cannot be approved for meat.”

The study concluded that GM feed is safe and the nutritional equivalent to non-GMO feed.

“Considering the size of the data set, it can reasonably be said that the debate over the impact of GE feed on animal health is closed: there is zero extraordinary impact,” Entine said.

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