TAIPEI (Taiwan News) — Researchers at Taiwan’s agriculture ministry have conducted experiments that reduced greenhouse gas emissions from dairy cows by 4.5% without affecting milk production.

The experiment reduced the cows’ protein intake and used agricultural byproducts as feed. The changes resulted in methane output dropping from 6,259 kilograms per cow to 5,975, the Ministry of Agriculture’s animal research unit said via press release on Friday (Sept. 13). 

The unit’s director, surnamed Huang (黃), said the experiment found that when cow pastures and other factors are fixed, reducing the protein content in their feed from 18% to 15% caused the reduction in methane production. They said the finding is highly significant for the future of environmentally friendly milk production.

Cows were fed agricultural byproducts including pear skins, lemon pulp, and grains from breweries in the experiment, which also made them produce less methane. Researchers said that in addition to not affecting milk production, the changes also reduced urea nitrogen levels in the cows, making them healthier.

Huang said the emissions calculations were made according to standards set by the United Nation’s (UN) Intergovernmental Panel on Climate Change. The animal research unit said it is continuing to work on “precision feed research” for cows to contribute to a sustainable dairy industry.

According to the UN, livestock are one of the greatest human-related producers of methane, a gas with a warming effect 80 times more potent than carbon dioxide. The UN recommends a 30% reduction in methane emissions by 2030, and that this should focus on reducing emissions from livestock.