Seaweed can help reduce the emissions of greenhouse gases from livestock. That is the goal of the research project Climate Feed funded by Innovation Fund Denmark which is developing a feed with seaweed which reduces methane from cattle.

The emissions of CO₂ and greenhouse gases from farming makes up 20 percent of the total emissions in Denmark. A large part of this comes from ruminant cows, that each burps between 500-700 liters of methane per day. Methane has more than 80 times the warming power of carbon dioxide over the first 20 years after it reaches the atmosphere.

A group of Danish companies and researcher is looking to change those numbers. With the Climate Feed project backed by the Innovation Fund Denmark, a feed additive consisting of seaweed is being developed for cows that can impede the formation of methane gas in their stomach.

Many advantages of using seaweed

The goal of developing a feed additive containing seaweed is not as far away as it may seem. Brown, red or green macro algae (seaweed) from Nordic seas contains a variety of bioactive compounds such as tannins and antioxidants. Nordic seaweed species have in certain concentration been documented to lower the production of methane produced in a cow’s stomach says the project manager Anne-Belinda Bjerre from Danish Technological Institute (DTI)

In the project methods of cultivating and following treating the seaweed into a finalized feed formulation in the shape of dried powder or pills that the farmer can easily add to the feed are being developed. The product needs a known and stable content of the active components that reduce the emission of greenhouse gases without impacting the milk production, taste and quality.

Seaweed has many attractive features. It is produced at sea and requires neither fertilizer nor fresh water to grow. On the contrary, it actually benefits from the nutrients that are expelled at sea from agriculture and aquaculture. In that way both a cleaner ocean environment and a more sustainable production system is obtained, says Anne-Belinda Bjerre.

Multiple promising species in Danish seas
The particular species that are used in the project are selected from the 400 species in Danish seas. In the project a few promising candidates have already been selected, for instance brown macro algae that already is being cultivated both in Denmark and near Faroe Islands at the company Ocean Rainforest.

The company Dansk Tang along with Aarhus University collaborats in the selection of the most suitable species and cultivation methods. The chosen species are processed in Danish companies Vilofoss and DLG, after which a herd of dairy cattle will be given the seaweed-based additive, while Danish Technological Institute, Aarhus University and SEGES documents the reducion of methane emissions from the cows.

Vilofoss, which is owned by DLG and thus Danish farmers, has factories located in 15 different European countries, and will be responsible for commercializing the final feed using seaweed-based additive with documented methane reducing effect on dairy cows.

The Danish dairy producer Naturmælk wants to be the first to produce milk from cows fed with seaweed-based additive. The expectations are that farmers supplying other dairy producers will want to use seaweed as additive in their feed.

The additive might also have additional benefits aside from the methane reduction, such as a lower requirement of feed consumed by each cow, since the containing carbon-bound energy is better utilized rather than being released as methane. Danish Technological Institute estimates that combined Nordic seaweed cultivation efforts can make up an area the size of the Danish island of Bornholm (588 km²). That would be enough to supply approximately 40% of the cows in the six largest dairy producers in the European Union and thereby significantly lowering the overall climate impact.