Red sea plume algae slashes cow poo emissions by nearly 50 percent, finds study

Scientists prove a specific species of red algae added to cow droppings significantly reduces methane emissions from stored feces.
Sade Agard
Asparagopsis taxiformis, also known as red sea plume
Asparagopsis taxiformis, also known as red sea plume

Jean-Pascal Quod/ Wikimedia Commons 

Researchers in Sweden studied the effect of adding Asparagopsis taxiformis (AT), or red sea plume, to cow feces on greenhouse gas emissions from dairy cow manure. 

Their study, published in Frontiers in Sustainable Food Systems, revealed that incorporating AT can potentially reduce greenhouse gas emissions from cow manure by almost 50 percent. 

The findings highlight the significant potential of red sea plume algae in mitigating emissions from livestock waste.

Red sea plume against greenhouse gases

"We showed that adding AT to the feces of dairy cows significantly reduced methane production from the feces by 44 percent compared to feces without AT," said Dr. Mohammad Ramin, an animal science researcher at the Swedish University of Agricultural Sciences, in a press statement.

AT, a red algae species in tropical to warm waters, has a cosmopolitan distribution. Its primary compound, bromoform, serves as a potent methane inhibitor, impeding gas generation. AT is currently the most promising natural solution for mitigating methane emissions.

"There have been many studies using AT in dairy cows' diets to reduce enteric methane production. However, no studies have reported on the decrease of methane emissions from manure," Ramin highlighted.

Supplementing cows' feed with AT has potential drawbacks due to its elevated iodine levels, which can lead to increased iodine concentrations in milk consumed by humans. 

Although iodine is vital, excessive amounts can be toxic, causing health problems like thyroid issues. Researchers are striving to cultivate AT variants with reduced iodine content in laboratory settings.

Nevertheless, AT proves effective in curbing methane emissions directly from manure, extending its benefits beyond addressing emissions from cows' digestive processes. This is the approach Ramin and colleagues successfully employed in their study.

Methane emissions from cattle

Ruminant livestock, such as cows, sheep, and goats, contribute to about one-third of human-caused methane emissions. 

These animals acquire nutrients by fermenting food in their specialized four-chambered stomachs. Methane is produced when they belch and when their manure decomposes under certain conditions.

The impact of manure on greenhouse gas emissions varies depending on factors like how it is stored. In the cool-temperate European climate, manure storage accounts for roughly 12 percent of total methane emissions from the dairy system.

"Manure methane production does contribute to global greenhouse gas emission and needs to be reduced," Ramin emphasized. "Our study showed a potential way how methane inhibitors could be utilized to do that."

Despite the promising findings, the researchers highlighted that their study was a pilot study involving only four cows' feces. They recommended that future research include more cows to collect manure from for more comprehensive results.

Additionally, they emphasized the need for further studies to explore the interactions between the alga's halogenated compounds and the microbiome of the fecal matter. This would provide a deeper understanding of how the alga influences the microbial communities in the manure.