Researchers from Aarhus University in cooperation with Organic Denmark and a number of commercial partners will be examining whether the addition of organic oregano to cattle feed can reduce the production of methane in the rumen and thus emissions of methane gas.
They hope to show that methane emissions from dairy cows can be reduced by up to 25 per cent by adding oregano to the feed.
Oregano – especially the species Greek oregano (Origanum vulgare ssp hirtum) – is known for its high content of essential oils and its antimicrobial effect. The plant is a natural tool for reducing methane production in the rumen, says project manager and Senior Researcher at the Department of Food Science, Kai Grevsen.
Researchers initially will test the effect of supplementing with oregano on rumen- and intestinal-fistulated dairy cows in special methane chambers. They will also examine how the cows react to different amounts of oregano. The feeding with oregano will then be tested in practice on a number of organic dairy farms producing milk for ‘Naturmælk’ (organic dairy).
The four-year project moreover will investigate how best to grow organic oregano and whether to process the plant either as hay or silage.
To succeed with the oregano project in practice, it is essential to develop a product that has both a high yield and a high concentration of essential oils, Grevsen says.
Developing an organic farming concept and breeding new varieties with higher concentrations of the oils, will be necessary too.
The climate will be the main beneficiary of the project if it is successful. But the researchers hope the project will also benefit arable and dairy farmers.
Previous studies indicate that oregano can improve the milk’s fatty acid composition, and the project participants will therefore be researching this aspect as well as the milk’s flavour.
Another hope is that the research will pave the way for a number of new products that can be sold on the basis of their climate-friendliness, targeting environmentally conscious consumers.
“We know that the market for dairy products is characterised by an increasing willingness to pay more for milk with special qualities or values, especially organic, and we hope that in the project we will have a good and balanced dialogue with consumers about the climate and cattle production,” says Grevsen.
“It’s also important to remember that the project is relevant not only for organic milk producers. Should the results be positive, they can be implemented on all cattle farms, conventional and organic, so there is a really large potential.”
The project is financially supported by the Green Development and Demonstration Programme under the Ministry of Environment and Food of Denmark and by the cattle and milk levy funds.
Project partners are the departments of Food Science and Animal Science at Aarhus University, Organic Denmark, Naturmælk, dairy farmers Frode Lehmann, Günther Lorenzen and Laust Stenger, and the commercial growers Urtefarm and Sunny.
The project is led by Senior Researcher Kai Grevsen from the Department of Food Science in collaboration with Senior Researcher Peter Lund from the Department of Animal Science, both from Aarhus University, and by Else Torp Christensen from Organic Denmark.