Genetically Engineered Livestock
Increasingly animals are being genetically engineered with traits proponents argue are more environmentally friendly and humane
Genetically engineered animals have been around since the early 1980s when scientists first genetically engineered mice, and now genetically engineered meat could be coming to your dinner plate. While genetically modified organisms are often unpopular among environmental and activist groups, proponents argue genetically engineered livestock have the potential to reduce the environmental impact of livestock production, create a more humane system of production, and even deliver biomedical benefits.
GM Atlantic salmon, developed by AquaBounty, for instance, is an Atlantic salmon engineered with a growth hormone regulating gene from Pacific Chinook salmon to grow year round so it reaches market size in 16 to 18 months rather than in three years. To prevent the GM salmon from escaping and breeding with native salmon, all the fish have been engineered to be sterile females.
This accelerated growth rate translates into a more efficient use of feed and could dramatically change the economic viability of land-based salmon operations closer to dense population centers. But the more efficient feed conversion ratio, potential for reduced food miles, and precautions to prevent genetic drift have done little to abate fears of activists, and the salmon have existed in regulatory limbo for two decades now.
Meanwhile, scientists at Recombinetics have developed hornless cows in order to bypass the painful process of horn removal in cows by disrupting a single gene in a process known as “gene editing.” Kevin Loria of Business Insider explains:
For decades dairy cows have had their horns cut or burned off to prevent injuries to the herd. Now a Minnesota company, Recombinetics, has used genetic manipulation to develop a hornless dairy cow, potentially ending a painful process — if regulators allow these creatures to be used.
Although we could develop hornless dairy cows through breeding, it would take vastly longer and pose more risks. We'd have to mate cows without horns with each other for generations until we got hornless offspring — yet we'd almost certainly lose some of the traits that make dairy cows the best milk producers in the world. It's much easier if you can just disable the genes that code for horns.
Loria emphasizes the unintended, and inhumane, consequences traditional breeding can have by reminding us that all 50 of the most popular dog breeds are predisposed to genetic disorders. Genetic engineering, in particular the recently discovered CRISPR-Cas9 system, allows scientists to much more precisely alter desired genetic traits in a more targeted fashion.
But even targeted genetic engineering can cause problems for animals. A team of scientists in South Korea have also used gene editing to develop a “double-muscled” pig by targeting the myostatin gene. More meat per animals raises the potential of satisfying demand for meat with less land and less animals. But as Nature explains:
Yin says that preliminary investigations, show that the pigs provide many of the double-muscled cow’s benefits — such as leaner meat and a higher yield of meat per animal. However, they also share some of its problems. Birthing difficulties result from the piglets’ large size, for instance. And only 13 of the 32 lived to 8 months old. Of these, two are still alive, says Yin, and only one is considered healthy.
Targeted genetic engineering has not only been used to manipulate existing characteristics of the animals; it has also been explored as an option to aid in greater medical dilemmas. Scientists have engineered pigs immune to African swine fever virus, goats that produce a potential malaria vaccine in their milk, cows that produce milk with the same properties as human breast milk, and a Harvard lab is working on genetically modifying pigs to be suitable organ donors for humans.
What do you think of genetically engineered livestock? Would you be willing to consume genetically engineered animal products? What about those with biomedical properties?