They do a lot of good for the environment, but their burps make up for it. Now it is being tested whether cows can become more climate-friendly – by allowing them to eat algae or dietary supplements that reduce harmful emissions.
Cows emit climate-damaging methane, primarily through burps, but also through farts, and the algae – Asparogopsis taxiformis – can reduce these emissions by up to 60 percent, according to research.
Large source of emissions
If this is true, the algae can be an important piece of the puzzle to reducing emissions from agriculture.
The culprit in the drama is the fermentation process that takes place in the cows’ largest stomach, the rumen, when they transform the grass. 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, 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.
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.
The fact that algae are a natural product, while the dietary supplement is chemically produced, can also make it better received by farmers.
One concern with the algae has been that bromoform should be transferred to the milk and meat. At high levels, the substance is carcinogenic. Previous studies have shown that the levels are significantly lower than they would be a risk.