Reducing methane emissions from cattle and dairy farming

Methane traps eighty-four times more heat than carbon dioxide. The IPCC says that whilst being a short lived gas (12 years) and existing in small atmospheric quantities of only 2 parts per million, a cut in methane emissions has the greatest potential to slow climate warming over the next two decades. Agriculture contributes to 40-45% of these global methane emissions, largely arising from cattle and dairy farming.

As a by-product of stomach fermentation in cows, methane is a naturally unavoidable gas emission from both ends of an animal. One cow generates up to 500 litres of methane each day, 7 gigatonnes of methane are produced annually through burping and flatulence, by over 1.6 billion cattle worldwide.

So what are humans to do? Give up meat and dairy whilst the population continues to increase? That is of course one line of technological investigation that has been taking place for over a decade – the advancement of cultured meat and dairy products continues apace. However there are a range of other technological solutions that will help to address the issue of methane emissions in traditional livestock farming.

Methane Emissions Research
In a White House announcement earlier this month, The US Department of Agriculture (USDA) stated that is pursuing multiple workstreams to reduce methane emissions from the agricultural sector, including

the adoption of alternative manure management systems and other methane-reducing practices.
the expansion of on-farm generation and use of renewable energy.
the development of a climate-smart agricultural commodities partnership initiative.
increased investments in agricultural methane quantification and related innovations.
At the US university of Cornell’s Department of Animal Science a lab upgrade is taking place which will see the installation of four climate-controlled respiration chambers. Placed inside the Large Animal Research and Teaching Unit, they will enable researchers to study the gas exchange of dairy cattle and other livestock, enabling scientists there to develop methane reducing solutions.

“These chambers are important because they’re the most accurate, gold-standard approach to measure methane emissions from dairy cattle,” says Joseph McFadden, associate professor of dairy cattle biology in the College of Agriculture and Life Sciences. “You can measure methane using other types of equipment, but they’re less accurate, or they don’t measure all the greenhouse gases animals emit or consume, and they don’t allow you to control the environment.”

Each chamber is big enough to comfortably hold one cow, a couple of sheep or several chickens. Researchers at Cornell will use the new facilities to understand how animals respond to changes in their diet – with the goal of optimizing livestock nutrition for efficient milk and meat production, minimum greenhouse gas emissions and nutrient waste, and enhanced animal health. The respiration chamber will be built and installed in spring 2022 by No-Pollution Industrial Systems, an engineering firm based in Scotland.

Scotland itself is set to become the base for a new factory that will produce a methane reducing feed additive already available for dairy cows. Owned by Netherlands-based DSM, the factory will manufacture Bovaer – a feed product comprised of natural compounds that reduces methane emissions during a cow’s normal digestive process. DSM state that a quarter teaspoon of Bovaer per cow per day suppresses the enzyme that triggers methane production in a cow’s rumen and consistently reduces enteric methane emission – by approximately 30% for dairy cows and even higher percentages of up to 90% for beef cows, with no health consequences.

“We are pleased with the Scottish government’s support of the build-up of our production capacity of Bovaer, particularly within the context of COP26, where the importance of fast climate action through reduction of methane emissions is emphasized again.” say Geraldine Matchett and Dimitri de Vreeze, co-CEOs of DSM “We are looking forward to offering a scientifically proven effective solution to the challenge of methane emissions by farming. As food systems and climate crisis are intrinsically linked, addressing the challenge of sustainable animal farming for a healthy planet is pivotal.”

   5 sustainable farming methods assessed

In September 2021, after ten years of testing and forty five on-farm trials, DSM received its first full regulatory approval to commercialise Bovaer from the Brazilian and Chilean authorities, for application in beef, dairy, sheep and goats. Brazilian company JBS SA, the world’s largest meatpacker, announced last week that it will give the additive to confined cattle, which would be the easiest to administer initially (though the majority of cattle in Brazil grazes freely).

Seaweed-based additives
Another livestock food additive showing good prospects for livestock methane reductions is seaweed. Scientists at the UK’s Institute for Global Food Security (IGFS) will feed seaweed to farm animals, a relatively new idea for methane management. Early lab research by IGFS has shown promising results using native Irish and UK seaweeds. The seaweeds are also rich in active compounds called phlorotannins which are anti-bacterial and improve immunity so could have additional health benefits for animals.

In partnership with the UK supermarket Morrisons and its network of British beef farmers, a three year project is about to commence. Trials on UK farms will use seaweed sourced from the Irish and North Seas as a feed supplement for cattle. A second project sees IGFS and The Agri-Food and Biosciences Institute (AFBI) join a €2million, international project – led by Irish agency An Teagasc – to monitor the effects of seaweed in the diet of pasture-based livestock. Seaweed will be added to grass-based silage on farm trials involving dairy cows in NI from early 2022.

As well as assessing methane emissions of the beef and dairy cattle, these projects will assess the nutritional value of a variety of homegrown seaweeds, their effects on animal productivity and meat quality. If successful the next hurdle would relate to supply and harvest, it is vital that any increased demand for seaweed as a methane control does not come with negative ecological impacts on marine habitats.

Effluent treatment systems
Even after a cow has completed the digestive process, its by-product – manure, continues to emit methane gas. Nearly all dairy farms use effluent or slurry ponds and they are the second largest source of on-farm methane emissions. At New Zealand’s Lincoln University, scientists Emeritus Professor Keith Cameron and Professor Hong Di have developed technology that reduces the methane emissions from dairy farm effluent ponds by up to 99%.

 Built in conjunction with New Zealand ag solutions firm Ravensdown, the ‘EcoPond’ virtually eliminates the methane emitted from effluent ponds. A computer-controlled pump and mixing system precisely administers iron sulphate – a safe additive used in the treatment of drinking water, to neutralise methane production. 

“The larger the pond, the more micro-organisms in the pond to generate methane. This new system has been tested in the lab and at farm scale, where it proves enormously effective at essentially nullifying the methane-creating process.” Explains Emeritus Professor Keith Cameron.

“We also found that EcoPond reduced the risk of Dissolved Reactive Phosphate loss to water by up to 99%,” adds Professor Hong Di. “This means that this essential nutrient can be recycled with reduced risk of water contamination. The EcoPond system also strips out E.coli so that the dairy effluent is much safer to irrigate to pasture.”

Overall an average New Zealand dairy farm of around 400 cows that installed EcoPond could cut total farm methane emissions by about 4-5%, depending on the individual farm.

“It is a simple, practical solution backed by science and one that every dairy farmer can understand and operate. It brings multiple benefits, not only in reduced methane emissions but also in increased nutrient capture and utilisation.” says Ravensdown Chair, John Henderson.

Use the methane – biogas powered machinery
All machinery manufacturers are considering alternative fuels to meet future environmental legislation, which has already resulted in continued updates to engines to cut emissions. The creation of a circular system would be the ideal scenario for most farm owners.

New Holland’s 179hp T6.180 tractor, recent winner of the ‘Sustainable Tractor of the Year 2022’ award at the EIMA Agricultural Trade Show, is capable of running on methane. Methane fuel can be supplied by an on-farm Anaerobic Digestion (AD) plant, using biogas that has been upgraded and compressed.

New Holland is exploring the concept of the ‘energy independent farm’ with customers who produce manure or biomass as feedstocks for biodigesters or have such facilities on their doorstep. For these farmers it’s not about neutralising the production of methane but capturing and using it. 

“Using biomethane produced from liquid manure cuts emissions by 180% and takes the operation into negative C02 as the process captures gas that would otherwise have been released into the atmosphere,” explains Mark Howell, Global Head of Renewables for New Holland.

Opportunities could also be offered for a small group of farms working together to produce gas which is exported to a central injection point, fuelling two or three tractors on each farm. “This is a common method of fuelling in Europe and has been successfully used in the public transport sector in the UK. In addition to the environmental benefits, the cost savings can be impressive, up to 80%.” adds Howell.

The obvious way to make use of a gas-powered tractor is in yard work such as feeding livestock, where it is running for a set period each day and the tank is refilled overnight, although quicker fills can also be made for field work such as haulage, where the tractor can frequently return to the yard to top up.

The future
Whether we’re cutting methane production from farm animals or using that methane as a renewable energy source, its certain that there are academic and corporate solutions in the pipeline that show great promise. Cost and practicality will always be key in farming, one would assume that a low-cost, feed-based solution would have more of an impactful global future in methane reduction, than a technology such as a methane trapping ‘cow mask’ – something being developed by the UK’s Zelp. What’s most important is that we recognise that nature is finely balanced, the systems that support us are fragile and humanity’s footprint is large. Cleaner livestock farming and agriculture relies on inventors and investors to do their best, we cannot realistically rely on short-term voter-dependent governments to make unpopular decisions.