Researchers found that the seaweed’s natural biomass reduced methane emissions by up to 40% more than bromoform by itself, indicating that other compounds within the seaweed are contributing to its potency in cutting methane.
Their study, which received funding from CH4 Global, aimed to compare the methane-reducing effects of whole Asparagopsis armata seaweed (AA) with pure bromoform (BF). The research also looked at how these additives affected fermentation and digestion in a lab setting.
Methane from ruminants is a major climate concern, responsible for around 30% of human-caused methane emissions. With methane having up to 80 times the warming potential of carbon dioxide over a 20-year period, addressing these emissions is a key strategy in fighting climate change. Recognizing this, over 150 countries have pledged to reduce methane emissions by 30% by 2030, making innovations like seaweed-based feed additives a hot topic in the agriculture sector.
Asparagopsis seaweed has gained attention for its potential to reduce methane emissions by over 80% in cattle when added to their feed in tiny amounts. While bromoform—a compound found in high concentrations within Asparagopsis—has been identified as the main methane-reducing agent, researchers have been exploring whether it is necessary to use the entire seaweed or if pure bromoform could be isolated as a feed additive. This new research, however, suggests that whole seaweed biomass may be more beneficial.
Lab generated data
In the study, scientists compared the effects of whole A. armata seaweed biomass with pure bromoform on methane production using in-vitro rumen simulation.
Researchers conducted lab experiments using a standard diet of 50% hay and 50% concentrate. The seaweed was evaluated at two levels, 0.25% and 0.50%, which provided specific amounts of bromoform. Bromoform itself was assessed at similar doses to those found in the seaweed.
The results showed that adding A. armata biomass led to a significant reduction in methane production—by up to 95.6%—without affecting fermentation. In contrast, bromoform reduced methane by a smaller amount, up to 59.6%. These findings suggest that while bromoform is effective, the whole seaweed has a stronger methane-reducing effect, likely due to other beneficial compounds in the biomass.
Source: Animal Feed Science and Technology
Title: The anti-methanogenic efficacy of Asparagopsis armata: Could it be attributable solely to its bromoform content?
Authors: E Ahmed, T Nishida
