Portable Accumulation Chambers to measure greenhouse gas emissions in sheep

More than 30% of the Earth's total land mass is used for grazing livestock production, mainly by ruminant animals, largely due to geographical constraints on arable production. The evolutionary adaptation of the ruminant's ability to convert pasture to animal products such as meat, milk, and fibre may have been successfully harnessed, but ruminant production has an unwanted by-product. During the breakdown of plant material in the rumen, excess hydrogen is produced, and this hydrogen is metabolized by rumen microbes and eructed by the animal as methane, a potent greenhouse gas. Methane is not only an environmentally detrimental waste product but also represents ~8% digestible energy loss to the animal. The scale of this problem means that the sustainability of profitable livestock farming throughout the world is increasingly threatened by methane emissions. Proposed global agreements to lower these emissions, such as those outlined in the Kyoto Protocol and the Paris Agreement, pose an economic challenge in countries such as the UK, New Zealand, Uruguay, Ireland and others where agricultural exports from pastoral production are a major economic driver. Given that global demand for meat and milk is estimated to increase by at least 1% per annum between now and 2050, strategies for mitigation that are applicable across geographically-distinct farming systems are needed. Such a strategy would be a major scientific, economic and environmental breakthrough. There are 1.1bn sheep in the world producing around 137.8M tonnes of CO2eq (or 6.56M tonnes of CH4) per annum. Therefore, global emissions of GHG (CO2eq) due to enteric fermentation of sheep accounts for 2.6% of total agricultural emissions (FAOSTAT 2016).

The overall objective of this proposal is to request funding for portable accumulation chambers (PACs) to measure methane emissions from sheep. This equipment is essential for the measurement of individual animals' methane emissions for use in GHG mitigation strategies such as breeding approaches. Breeding animals that emit lower levels of methane is a sustainable and cumulative way to address the issue of lowering carbon emissions from Agricultural production and this equipment is integral for this to be enabled for the sheep (and potentially also goat) sectors. The UK lags behind other major sheep-producing nations such as New Zealand, Australia, France and Ireland, in that is does not yet have the equipment required to enable the integration of GHG emission reduction into sheep breeding programmes. New opportunities will be unlocked to collaborate with industry partners in projects that will use the equipment for genetic, genomic and nutritional approaches, amongst others. In particular, PAC equipment can be used to investigate links between methane emissions and information generated from the rumen microbiome, which is currently actively being addressed as part of an international EU-funded research project (GrassToGas) in which SRUC is a partner.