The Welsh sheep industry is turning to genetic selection to reduce methane emissions without negatively affecting important traits like grazing ability.

Over the next three years a £2.9m initiative, funded by Defra’s Farming Innovation Fund, will measure methane emissions from 13,500 sheep in 45 flocks.

By analysing the anonymised data, the researchers hope to breed sheep with a naturally low carbon footprint, creating an Estimated Breeding Value (EBV) that combines methane yield, feed efficiency, productive lifetime efficiency and health.

Sheep would be ranked on their genetic potential to reduce carbon footprint to allow farmers to easily identify the low emitters.

So far it only involves Innovis, Exlana, Lleyn, Poll Dorset and Dorset Horn sheep but other breeds are being encouraged to participate.

In the UK around 50-60% of a sheep farm’s carbon footprint comes from their flock’s enteric methane – how sheep ferment their feed; the industry has set a target to reduce this by 30% by 2030.

Sheep geneticist Dr Janet Roden, of Innovis, at Capel Dewi, near Aberystwyth, said the aim of the project was to produce efficient maternal sheep with a naturally low carbon footprint but with efficiency and health improvements too.

But breeding a sheep to reduce methane emissions can reduce the size of its rumen and alter the way microbiome organisms work and this can have consequences for feed intake and grazing behaviour.

The challenge from this research will be to avoid unintended consequences for other traits, such as the ability to utilise poor quality grazing.

Phil Stocker, chief executive of the National Sheep Association, said protecting other traits was crucial.

“There is no point in selecting for low methane if we lose other valuable traits,’’ he warned.

New Zealand sheep breeders are already ahead of the curve with a decade of research on breeding values for methane emissions – its ‘net zero’ labelled lamb is already available to the consumer.

Innovis CEO Dewi Jones said it was important for the UK to protect the credentials of its own lamb, by demonstrating that the industry was not “shirking away’’ from its requirement to reduce emissions.

Currently only 15-20% of UK flocks use performance recorded maternal rams in their breeding programmes so the challenge will be to get more farmers on board once the project has ended, he added.