Sheep grazing on moorland emit lower levels of both methane and carbon dioxide (CO2) than those grazing improved grasslands, according to a new study.
These findings come from Forage for CH4nge, a UK-funded research project supported by the National Sheep Association (NSA), which brought together farmers and scientists to better understand how forage type, landscape and traditional sheep breeds influence the environmental footprint of upland sheep farming.
The project measured greenhouse gas emissions from native Swaledale ewes and commercial Texel-cross ewes grazing different forage types across the Yorkshire Dales National Park.
The results showed that sheep grazing on unimproved moorland forage produced significantly lower methane and CO2 emissions than those grazing on improved or herb-rich grassland.
NSA worked alongside project partners, including the Game & Wildlife Conservation Trust (GWCT), UK Agri-Tech Centre, Scotland’s Rural College (SRUC), the Yorkshire Agricultural Society and local farmers, to ensure the study delivered practical, farmer-focused evidence relevant to the future of upland sheep systems.
The study found that native Swaledale ewes produced less methane overall than Texel-cross ewes, mainly due to their smaller body size.
When methane emissions were adjusted for liveweight, there was little difference between the two breeds.
However, sheep of both breeds produced more methane per day when grazing improved grassland compared to moorland forage.
Native Swaledale ewes also produced less CO2 than crossbred ewes, even after adjusting for weight.
Three forage types were studied that reflected typical upland systems:
- Improved grassland consisting of fertilised and reseeded ryegrass leys designed to maximise yield;
- Herb-rich grassland, i.e., unimproved pasture that had received no fertiliser or farmyard manure for more than 30 years;
- Moorland forage comprised unimproved rough grazing including heather, bilberry and other upland shrubs on higher ground.
Nicola Noble, NSA project manager said: “This study provides crucial evidence to help demonstrate the current and future importance of sustainable upland sheep farming.
“It is great to finally be able to share these results after almost a year and a half’s work on this project.”
Study
In total, 120 sheep, including 60 Swaledales and 60 Texel-crosses, grazed on one of these three forage types.
Methane and CO2 emissions were measured using mobile portable accumulation chambers (PAC), with individual sheep being monitored for 50 minutes under carefully controlled, low-stress conditions.
Liveweight and body condition was also recorded for accurate comparisons.
The study also highlighted the broader climate value of upland landscapes, finding that well-aerated moorland and upland grassland soils can act as a methane sink, an ideal condition for methane metabolising bacteria to break it down in the soil.
Lead farmer involved in this work, Adrian Thornton-Berry said: “Forage for CH4nge is about showing that farmers are key to a sustainable future for Britain’s uplands.
By working with native breeds like the Swaledale, we can farm these sensitive landscapes in a way that protects them for future generations.”
NSA policy manager Michael Priestly added that the sheep sector is committed to reaching net zero by 2040, with reducing methane set to be part of these efforts.
