July 25, 2021


affection for others

Dutch study see risks from feeding certain types of seaweed to dairy cows

“Bromoform inhibits the formation of methane in the cow’s rumen. However, it is also toxic,”​ said Wouter Muizelaar, researcher at Wageningen Livestock Research. Previous research linked A. taxiformis to abnormalities in the rumen wall of sheep. “That is why we wanted to know what effect A. taxiformis has on cows. Does bromoform end up in milk, urine, manure, or in animal tissue? What happens with it? This research shows that bromoform from A. taxiformis can end up in milk and urine.”

He said this may be a factor to consider in estimating whether it is desirable to feed this type of seaweed to cows.

The research cannot be seen as conclusive, though, said Dr Jan Dijkstra, associate professor in ruminant nutrition, Wageningen University animal nutrition group, citing the small number of animals involved in the study and some problems in feeding the seaweed.

“We emphasize the need for further research, however, to ensure no negative effects for cows or milk quality to occur,”​ he told FeedNavigator. 

Cows exhale the strong greenhouse gas methane. One of the possible ways to limit methane emissions from cows is by feeding them the seaweed. 

Looking to other seaweed species

Muizelaar said that other seaweed species contain less or no bromoform but may also reduce methane. “They work slightly differently because they contain other methane inhibiting compounds. So I still see seaweed as a promising option that we should continue to explore.”

Last year we reported on work​​ by a Danish team looking to seaweed, probiotics, and other strategies to reduce methane output in dairy cows.