Scientists in the UK are genetically altering dairy cows so they have no horns, in a bid to make them safer and to cut the risk of injury to farmers and animals.
The sophisticated gene-editing technique involves inserting a DNA patch into the genome of Holstein cows, the UK’s foremost dairy breed.
The extra DNA is taken from other breeds of cattle, in which it is known to suppress horn growth.
Scientists aim to create a genetically modified dairy cow, identical in every respect to existing livestock but without the horns and safety risks, The Sunday Times reported.
“This would be a major advance in animal welfare,” said Geoff Simm, a professor of animal breeding who chairs the government’s Farm Animal Genetic Resources Committee.
Simm championed the idea in a report on livestock genetics published by the UK’s Department for Environment, Food and Rural Affairs (Defra), the food and farming ministry.
Simm’s technique is a new form of genetic engineering that lets scientists make precise changes to DNA and was recently used by scientists at Edinburgh’s Roslin Institute to create gene-edited pigs that can resist disease.
Scientists are now working with Scott Fahrenkrug, professor of genetics at the University of Minnesota, who is using similar techniques to create hornless Holstein cattle.
Fahrenkrug has already taken a short strip of DNA from the genome of Red Angus cattle, where it is known to suppress horn growth, and inserted it into cells taken from an elite Holstein bull named Randy.
“We have already made millions of modified cells.
Next we will use cloning technology to turn some of those cells into 40 embryos and implant them into a herd of surrogate mothers, in the mid-West of America, within weeks,” he said.
Each of the resulting animals will be a clone of Randy — but without horns.
Their offspring should also be hornless — creating the potential for horns to disappear from the whole breed in a single generation, the report said.
According to the UK’s Health and Safety Executive, five farm workers were killed and 91 injured by cattle in 2010-11. Two members of the public were also killed, and 17 more seriously injured.