Does breed type influence methane emissions from grazing cattle?
Welsh Black cattle
20 October 2014
IBERS study into the role of traditional and modern breeds of beef cattle in influencing methane emissions has been published in the journal PLOSONE.
The paper Traditional vs Modern: Role of Breed Type in Determining Enteric Methane Emissions from Cattle Grazing as Part of Contrasting Grassland-Based Systems is available online here.
The study was the first to quantify methane emissions for free-ranging beef cattle pastured on common grassland types in the lowlands and the uplands.
Scientists at The Institute of Biological, Environmental and Rural Sciences (IBERS) collected data from steers of a modern, fast-growing crossbreed (Limousin cross) and a smaller and hardier native breed (Welsh Black) when grazing lowland perennial ryegrass at Penglais Farm in Aberystwyth and an upland mixed pasture located at 540m above sea level, in the Cambrian Mountains.
Overall, any effects of breed type were relatively small compared to the combined influence of pasture type and location.
The amount of methane produced per day was lower for cattle in the uplands, whereas methane emissions per unit of live-weight gain were lower for cattle in the lowlands due to growth rates being higher on the ryegrass.
The lead author, Dr Mariecia Fraser of IBERS, a grazing ecologist specialising in management of upland systems said; “These results will have an important role to play in producing refined carbon footprints for different beef systems. The grasslands found in the hills and uplands of the UK support a variety of ecosystem services, such as biodiversity and landscape character, which are frequently dependent upon livestock farming.”
Cattle and sheep turn forages and poor-quality feeds into human edible foods, but there is an inevitable environmental cost in terms of release of pollutants.
Methane is a significant contributor to greenhouse gases and hence to global climate change. Agriculture is the source of about 38% of total UK emissions of methane, and of this about 85% comes from burping livestock.
Despite the prevalence of pasture-based beef production systems across Europe very few studies have measured methane emissions from grazing cattle.
It is possible that differences in physiology or behaviour could influence emissions from traditional and modern breeds depending on the nature of the herbage being grazed.
The study was carried out as part of the ‘Improvements to the National Inventory: Methane’; a UK-wide collaborative project led by IBERS.
Project leader Dr Jon Moorby said; “The data generated will strengthen the limited evidence base for future policy development regarding climate change mitigation and adaptation strategies within pastoral livestock systems.”
This work was funded by UK Department for Environment, Food and Rural Affairs, the Scottish Government, the Northern Ireland Department for Agriculture and Rural development, and the Welsh Government, as part of the UK’s Agricultural GHG Research Platform.