'Super-sires' DNA breakthrough will see elite cows and chickens grow bigger

Burgers may never be quite the same again. From the scientists who brought us Dolly the Sheep comes the ‘super sire’, a band of ‘elite’ cows, pigs, goats or sheep that may just be able to  impregnate a herd with genetically edited sperm.

Scientists from the Roslin Institute in Edinburgh, part of the University of Edinburgh, working with three US universities have announced a revolutionary breakthrough that promises to alter the future genetic makeup of animals.

The new breeding technology, it is being claimed, could ‘speed the spread of desirable characteristics in livestock’ as well as ‘improve food production for a growing global population’.

Critics however said genetically edited breeding was likely to harm animals and create so-called 'Frankenstein breeds' that could be too big or could produce more milk than they should.

Starting on mice, the research team took animal embryos and then knocked out the gene specific to male fertility creating males that were infertile. The male animals – first the mice and then larger animals pigs, goats and cattle – grew up sterile.

The infertile animals then received transplanted sperm-producing stem cells from surrogates. The sterile animals, healthy according to the researchers in every other way, then began producing sperm derived from the donors’ cells.

The mice, according to the researchers, “fathered healthy offspring” that carried the genes of the donor mice. The larger animals have yet to be bred.

Jon Oatley, a reproductive biologist at Washington State University, who is leading the research said: “With this technology, we can get better dissemination of desirable traits and improve the efficiency of food production.

"If we can tackle this genetically, then that means less water, less feed and fewer antibiotics we have to put into the animals.”

Professor Bruce Whitelaw, of the Roslin Institute, that pioneered the cloning of Dolly the Sheep, said: “This shows the world that the technology is real. It removes the need for artificial insemination or any surgical intervention. Your animals become an artificial insemination unit.”

The scientists used a ‘gene-editing’ tool – called CRISPR-Cas9 – to produce mice, pigs, goats and cattle that were then born without the gene called NANOS2, which meant they grew up sterile.

The scientists admitted that although they can now produce ‘surrogate sires’, the technology could not be commercialised because of current regulations that prevent gene-edited animals entering the food chain.

Dr Helen Wallace, director of GeneWatch UK, a not-for-profit organisation that aims to ensure genetic science and technology is used in the public interest, was highly critical of the research to make animals infertile and then fertile again.

Dr Wallace said: “The process of producing surrogate sires is likely to harm animals, as genetic engineering, including gene editing, involves many failed attempts, particularly in mammals.

"There are usually multiple stillbirths and early deaths during the process of producing one gene edited animal. In addition, it is still unclear whether this will ever work in farm animals.”

Liz O’Neill, director of GM Freeze, an organisation that campaigns for a moratorium on genetically modified food and farming in the UK, said: “We already grow enough food to feed the predicted peak world population (expected in 2050) but the poor are hungry and the rich overweight.

"If feeding people was really the priority here, our best brains would be focused on addressing food waste, overconsumption and the unfair distribution of global wealth, rather than promoting hypothetical hi-tech approaches that put animal welfare very low down the list of priorities.”