Cattle and other ruminants are significant producers of the greenhouse gas methane – contributing 37% of the methane emissions resulting from human activity.
A single cow on average produces between 70 and 120 kg of methane per year and, worldwide, there are about 1.5 billion cattle.
Methane is a greenhouse gas.
A significant source of human-made methane emissions is fossil fuel production. For example, methane is a key by-product of the rapidly rising global extraction and processing of natural gas. Other top sources of methane come from the digestive process of livestock and from landfills, which emit it as waste decomposes. Why Methane Matters UNFCCC
An international team of scientists led by Professor John Wallace of the Rowett Institute at the University of Aberdeen, has shown it is possible to breed cattle to lower their methane emissions.
Professor Wallace said:
“Previously we knew it was possible to reduce methane emissions by changing the diet or by using certain feed additives. But changing the genetics is much more significant – in this way we can select for cows that permanently produce less methane.”
The study was carried out on dairy cows although it is felt it will also apply to beef cattle.
Co-author Professor John Williams, from the University of Adelaide’s School of Animal and Veterinary Sciences added:
“Breeding for low-methane cattle will depend on selection priorities such as meat quality, milk production or disease resistance.
“We now know it’s possible to select for low methane production. But it depends on what else we are selecting for, and the weighting that is placed on methane – that’s something that will be determined by industry or society pressures.”
The researchers also found a correlation, although not as high, between the cows’ microbiomes and the efficiency of milk production.
Professor Williams said:
“We don’t yet know, but if it turned out that low-methane production equated to greater efficiencies of production – which could turn out to be true given that energy is required to produce the methane – then that would be a win, win situation.”
The research was published in Science Advances.