Does seaweed have an effect on methane formation in cows?

Preliminary results from the Seaweed project in healthy dairy farming

Can seaweed reduce methane emissions when fed to dairy cows as a dietary supplement? This is the question that a group of partners from business, science and society has been considering together since 2018. The relevant organizations – BlueO2, LTO Noord, Wageningen Livestock Research, CONO cheese makers, Hortimare, De Heus Voeders and Greenport Noord-Holland Noord – expect this research to make a concrete contribution to both the Dutch climate goals and a future-proof agricultural sector. 

The project on seaweed as animal feed was carried out in phases, the first phase being a literature study into suitable seaweed species. Wageningen Livestock Research examined the chemical composition of eleven seaweeds and tested them for their capacity to reduce methane formation in cattle. These results were sufficiently positive to proceed to a cow feeding experiment. The practical experiment was carried out on the Dairy Campus in Leeuwarden. Three types of seaweed were used during ten weeks, namely: (1) Chondrus crispus, (2) Saccharina latissima and (3) 50/50 Fucus serratus + Saccharina latissima. The seaweed was added to the feed in small doses. The methane production was then measured for each seaweed species. In addition to methane production, the amount of feed intake, animal health and milk production were also monitored.

The laboratory study showed a significant decrease in methane in a number of seaweed species (5-10%). However, this result could not be reproduced in the field study. No reduction in methane emissions has emerged, but there may be an increase in milk production.

The study showed that the feed intake of the seaweed treatments was equal to the feed intake of the control group without seaweed. In addition, it has been found that one seaweed treatment led to a significantly higher milk production (in number of kilograms). This is strongly related to a significantly higher lactose content (in grams per day) in this milk. The fat and protein contents of the milk in all seaweed treatments remained unchanged and were equal to the control. None of the seaweed treatments had an effect on enteric methane emissions from the rumen through the mouth and nose of the cow. A possible explanation for this is that the dose may have been too low to measure a noticeable effect.

Exact figures and results from the study will follow in a scientific publication, which will be available in mid-2021. Watch the film about the project now at Follow-up research into methane reduction in seaweed focuses on dosages and processing methods, which is further addressed by some of the partners (LTO Noord, BlueO2, Wageningen Livestock Research, Hortimare and De Heus Voeders).

Background project Seaweed in healthy dairy farming

The Seaweed in a Healthy Dairy Farming project investigates the practical application of seaweed in dairy farming. Together with a broad consortium of companies, (possible) bottlenecks within this theme are investigated, from seaweed cultivation to feed intake. The project contributes to the future-proofing of two agricultural sectors: dairy farming and the seaweed sector. One is closely linked to Dutch traditions, the other has the potential to become the Dutch sector of the future. Connecting these sectors has great potential to create positive synergy for the economy, climate and agriculture.

This project was made possible by the province of Noord-Holland and ELFPO; “European Agricultural Fund for Rural Development: Europe invests in its countryside”.

Co-financed by the Dairy Fund, Top Sector Agri & Food and the Ministry of Agriculture, Nature and Food Quality in collaboration with all partners.