This is how the dangerous rapes of the cows should be stopped

They do a lot of good for the environment, but their rapes make up for it. Now it is being tested whether Swedish cows can become more climate-friendly – by allowing them to eat algae or dietary supplements that reduce harmful emissions.

In a barn outside Umeå, 30 cows have recently received an unusual ingredient in their feed. For three months, it has been spiked with chopped algae, at the same time as the levels of climate-damaging methane gas are measured in the cows’ exhaled air.

Cows emit climate-damaging methane, primarily through beetles, but also through farts, and the algae – Asparogopsis taxiformis – can reduce these emissions by up to 60 percent, according to research from other countries. But since the cows’ feed has different composition in different countries, the question is how it works in Sweden.

Preliminary results from the Umeå cows look promising.

– The analyzes are not complete, but when we look at data, we see clear effects on methane emissions, says Rebecca Danielsson, researcher at the Swedish University of Agricultural Sciences, SLU.

Large source of emissions

If this is true, the algae can be an important piece of the puzzle to reduce emissions from agriculture. Ruminants are one of the largest emitters of the climate-damaging methane, and in Sweden the cows’ feed digestion contributes to just over a third of the agricultural sector’s greenhouse gas emissions.

The culprit in the drama is the fermentation process that takes place in the cows’ largest stomach, the rumen, when they convert grass into milk and meat. Then hydrogen and carbon dioxide are formed which microorganisms in the rumen use to get energy – and in that process methane is formed.

Here the algae enter the equation. They contain the substance bromoform which blocks an enzyme in the microorganisms and thus stops the formation of methane.

The Bovaer dietary supplement, which earlier this year was the first in the field to be approved within the EU and which will now be tested in Sweden, works in a similar way. Starting this autumn, 5,000 Swedish dairy cows will receive the dietary supplement in their feed within a project that Arla runs in Sweden, Denmark and Germany.

According to previous research, dietary supplements can reduce methane emissions by around 30 percent.

– We already know that Bovaer works, and the purpose now is to see in practical terms how it works for the farmers to challenge with it in the barns, says Åse Arnbratt at Arla.

Is the milk affected?

Bovas reduce methane by holding down the same enzyme as the algae. But the algae seem to contain more substances that reduce methane, which probably makes them more effective, according to Rebecca Danielsson.

The fact that algae are a natural product, while the dietary supplement is chemically produced, can also make it better received by farmers, believes Rebecca Danielsson. Bovas can also not be used by Krav farms where the use of chemically produced substances is prohibited.

One concern with the algae has been that bromoform should be transferred to the milk and meat. At high levels, the substance is carcinogenic. In Umeå, the researchers therefore measure how much is transferred to the milk, the cows’ urine and manure. Previous studies have shown that the levels are significantly lower than they would be a risk, according to Rebecca Danielsson.

– But this is something that needs to be followed up more carefully to know for sure that it does not have negative effects on humans or animals in the long term, she says.

Wants to grow 50 tons of algae

A challenge is also to produce sufficiently large amounts of algae. Those with which the cows in Umeå are fed have been harvested by divers off the coast of Portugal – that is, far from locally produced.

Maybe the solution is outside Lysekil. Attempts are being made to grow the algae in large water tanks in a test factory built by the company Volta Greentech. Last year, the cultivated algae were tested on 20 beef cows on a farm outside Eskilstuna, while the emissions were measured in the same way as in Umeå.

– We reduced methane emissions by 80 percent, says Fredrik Åkerman, one of the founders of Volta Greentech, who is now planning a larger factory where it will be possible to grow 50 tonnes of algae annually.

Different kinds of supplements in the cows’ food are a way to get rid of the emissions. Another way that is under development is that the cows may have a mask over the cloud that catches the methane in each rap. The mask converts methane to water vapor and carbon dioxide, which can reduce methane emissions by about 50 percent, estimates the British company behind the invention.

At the same time, cows are not only bad for the environment, they also contribute to open landscapes and biodiversity through their grazing. And in relation to other sources of emissions, Rebecca Danielsson thinks that in Sweden sometimes a lot of focus is placed on the cows’ bumps and farts.

– But now emissions need to be reduced quickly, and then you have to do everything you can in all sectors.

Facts

Methane emissions from cows

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