Greenhouse gases in cow burps warm up the climate. To mitigate this effect, researchers at Luke study different feeding and breeding strategies to reduce the amount of methane emitted by cattle.
Year after year, the Earth has hit new record high levels of heat-trapping greenhouse gases in the atmosphere. To avoid the most destructive effects of a warming climate, emissions of greenhouse gases need to be cut rapidly and in all sectors of our societies. Even cows play a role in this effort.
Ruminants like cows have an impact on climate because they burp a lot of methane, a potent greenhouse gas. As there are over a billion cattle in the world, cutting their emissions could help slow down climate change substantially.
Scientists at the Finnish Natural Resources Institute (Luke) are interested in what controls methane production in cattle.
“Cows are very valuable creatures. They provide high-quality food and necessary work power especially in poorer countries,” says senior scientist Alireza Bayat from Luke.
“But we need to solve the methane problem.”
Nutritional interventions have potential
Cows burp out around 95% of all the methane they emit. The rest come out from the other end of the animal.
The reason behind these emissions are microbes. They live in specialized compartments in ruminants’ stomachs and allow their host to digest feed very efficiently. The climatic downside of this collaboration is that the microbes do their work in anaerobic conditions and produce methane as a byproduct.
Alireza Bayat and his colleagues study the effect of nutrition on these emissions.
“So far, nutritional interventions have been the most promising way to reduce emissions from ruminants. At Luke, we have tested strategies such as adding different fats and oils to the cows’ diets, and proven that they reduce methane emissions.”
Research is also ongoing on other kinds of feed additives that inhibit enzymes involved in methane production. Certain compounds have been found to reduce methane emissions from cattle by up to 60%, without adversely affecting the health and performance of the animals.
Bayat and his fellow researchers at Luke have also found that along with diet and microbes, individual properties of cows affect methane emissions.
“Our results do not let us make clear conclusions on a single most important factor in reducing the emissions,” Bayat describes.
“It’s a complex system that you can study from different angles. But we are a team – we complement each other.”
Special chambers make the research possible
The research is conducted at a special facility in Jokioinen, Finland, where Luke has four metabolic chambers. They allow studying dairy cows’ energy metabolism and methane emissions with a ‘gold standard’ technique.
“The chambers have been used to generate invaluable data for scientific purposes,” Bayat says.
“By using them we can measure the cows’ energy expenditure and methane production under different experimental conditions.”
The metabolic chambers have been utilized for example to examine the effect of antibiotics on methane emissions, and test different dietary strategies on cows that emit low or high amounts of methane.
“Thanks to their transparent view and friendly conditions, the chambers do not affect feed intake and milk yield of the cows,” Bayat explains. “To my knowledge Denmark is the only other Nordic country with a similar facility.”
Luke also does international collaboration on the topic. Luke’s research and empirical evidence from the chambers have contributed to improving scientific models that predict methane emissions from cattle in different regions and under different nutritional conditions.
Text: Antti Miettinen
Could breeding be used to cut emissions?
If methane production of cows has a genetic and heritable basis, breeding individuals that emit less methane than others could be used to mitigate emissions from cattle. However, this requires that lowering methane production does not negatively affect other important traits of the animal, such as milk production and health.
“Improving livestock genetically is cost-effective. If it works, it offers a potentially long-term and sustainable strategy to lower methane emissions from dairy cows,” explains Luke’s senior scientist Enyew Negussie.
Knowledge of the actual genetics behind methane production in cattle is only starting to build.
“Luke is one of the pioneers in this area of research. Since 2013, we have been collecting data and built a unique database of individual cows’ methane emissions and related traits. Realistic estimates of genetic parameters will soon be available,” Negussie says.
Negussie says breeding for efficient feed utilization is one of the most promising strategies to reduce emissions. He and his colleagues at Luke have worked on the topic in a joint Nordic project called FUNC (Feed Utilization in Nordic Cattle).
“Methane emissions are mostly determined by how much and what the animal eats. By breeding for feed efficiency, we can promote cows that eat less but produce as much or more milk than their peers. This reduces both methane emissions and farmers’ feed costs.”
Negussie emphasizes the importance of co-operation across scientific and national boundaries.
“The problem with methane emissions is multi-faceted, so collaborative work across different disciplines is needed to bring about a sustainable and long-term solution to it.”