Cows get climate smart
Gene-editing can help create more milk, less methane and heat tolerance
Scientists will use gene-editing technology to create New Zealand’s first “climate-smart” cow. In a $10m study, AgResearch scientists aim to produce dairy cattle that have better milk production, greater heat tolerance and fewer emissions.
AgResearch senior scientist Bjorn Oback said dairy cows had a “mutually detrimental” relationship with climate change — they both contributed to it through greenhouse gases like methane, and would suffer from its impacts.
But building in the traits that would slash emissions and adapt them to a warmer world couldn’t be done through conventional breeding, for the simple reason it would take too long. Genomic selection and editing could speed things along.
AgResearch has developed methods to zero in on genetic gains, as far back as the early embryo stage, which are starting to be used in largescale commercial breeding.
In a five-year programme, Oback and colleagues want to expand this concept into a new platform that would combine cutting-edge gene editing technology with strategies to rapidly multiply chosen embryos.
They are genetically introducing two known variants predicted to improve milk production and cow comfort under heat stress.
One variant, involving a change in the cow’s prolactin receptor, was known to help with tolerance to heat and resistance against parasites. The other would help cows adapt to hotter grazing conditions by lightening the colour of their coats.
The team would evaluate the gene-edited cattle to check their interventions had succeeded.
Next, they planned to add more genetic variants linked to other beneficial traits, such as excreting less damaging nitrogen and producing fewer greenhouse gases.
Oback said these particular variants were either already known or were in the process of being discovered.
“Genome editors drastically reduce costs and timelines to bring new products to market,” he said.
At AgResearch, Oback and colleagues had access to the largest genome datasets in the country, along with several major gene discovery platforms turning out new candidate variants.
The programme would also confront the long-standing contention surrounding gene-editing itself.
“Even though genetic modification technologies and products are safe, they are shrouded in public controversy,” Oback said. “Resolving this dichotomy requires a responsible research and innovation approach.”
The research team would consider whether there would be public support for gene-edited cows, and look at how consumers might respond.
Under current legislation, genome editing of livestock is classified as genetic modification and heavily regulated under the Hazardous Substances and New Organisms Act.
AgResearch had gained approval to develop and maintain genome edited cattle, within the country’s only EPA-approved large animal outdoor containment unit.
Approved for 200 cattle, the double-fenced, 46 ha unit included animal handling, milking, surgical facilities, along with portable weather stations required for the tests.
Oback saw climate change as an “unprecedented challenge”, and said new technologies could play their part in battling it.
“Producing fitter, healthier and more sustainable animals is vital in the face of environmental challenges, pest and disease pressures, and changing consumer preferences,” he said.