Cattle are often singled out as a major source of greenhouse gases. Methane, in particular, is said to contribute roughly 30 times more to global warming than CO₂ over a 100-year period. Cattle alone account for nearly 5 percent of global CO₂-equivalent emissions.

Researchers have been working intensively for years to reduce methane emissions from livestock. According to The Washington Post, scientists from the University of California and the Innovative Genomics Institute are developing a groundbreaking method: genetically modifying the microbiome of a cow’s first stomach to make cattle more climate-friendly.

Using the CRISPR/Cas9 gene-editing tool, they aim to alter the microorganisms in the rumen so that less methane is produced. The idea is to create new microbes that deprive so-called archaea — the microorganisms that form methane — of the “food” they need before the gas can be generated. In this way, methane emissions could be reduced in the long term without changing the cows themselves.
Archaea feed on hydrogen (H₂) and carbon dioxide (CO₂) and convert these substances into methane (CH₄).

Methane innovation made in Valais

If the researchers succeed, billions of cows around the world could become more climate-friendly — without any change in diet. The Californian team is not alone in this effort. The Dutch company DSM has already developed a feed additive that can reduce cows’ methane emissions by 30 to 90 percent. The product is manufactured by a company based in the Swiss canton of Valais.

Due to Switzerland’s moratorium on genetic engineering, Swiss farmers cannot yet benefit from such innovations. A maize variety developed with new breeding technologies and proven to reduce cows’ methane output cannot be cultivated in Switzerland.

Alongside genome editing, the Californian researchers are also experimenting with natural additives such as algae oil, which can cut methane emissions by up to 80 percent. The oil blocks a key enzyme involved in methane production. This approach could help eliminate a significant share of global emissions and drastically reduce livestock’s impact on climate change.
However, feed additives have the drawback that they are less practical for animals that graze outdoors.

Despite promising research, the challenge remains immense. The cow’s microbiome has evolved over millions of years, making it difficult to bring about lasting change. Nevertheless, the scientists are optimistic that their work could lead to more sustainable farming practices.

This research highlights the vast potential of genome editing to address environmental challenges.