The relentless gaseous expulsions cattle are renowned for have called for some interesting efforts to tackle their climate change-contributing emissions. Previously, scientists have tried strapping backpacks to the poor ruminants to collect the gases they release in the hope of monitoring their emissions and ultimately turning them into a useful product, namely biofuel. Now, researchers have come up with another intriguing idea to curb their wind: cleaning up their burps.
Yes, I said burps, not farts. Contrary to widespread belief, it is the former that is a major contributor to greenhouse gas emissions, so give their rear ends a break. Much like humans, the guts of ruminants (cud-chomping, hoofed mammals such as cows and sheep) are loaded with microbes that aid the breakdown of food as it passes through their four stomach chambers. Unfortunately, in one of these parts, the rumen, the microbial-assisted fermentation of food releases a whole lot of methane and CO2, the former of which has a significantly higher global warming potential.
This process is actually the biggest source of human-induced methane emissions in the U.S., making up 25% of the total. But it’s not just the biology of ruminants that is to blame: production and processing of their feed, storing their manure and transportation of animal products all rack up a significant amount of greenhouse gas emissions. So how do we go about tackling this? Attempting to reduce the amount of meat and dairy products consumed is an obvious solution, but that is far easier said than done given the world’s taste for these foods. Instead, scientists are now trying out a novel solution: reducing their burps.
To do this, researchers added varying amounts of a methane-inhibiting compound – 3NOP – to the feed of 48 dairy cows and then monitored their emissions for a total of 12 weeks. This molecule works by blocking the action of an enzyme, coenzyme M reductase, which is involved in the final step of methane generation.
As described in Proceedings of the National Academy of Sciences, while food intake and milk production were unaffected, the inhibitor was found to reduce methane emission by around 30% when compared with control animals. Furthermore, the pathway of methane production actually results in a loss of energy in the animal, so with less generated, the animals are able to invest the extra energy back into the body for things like tissue growth. This was demonstrated by the fact that those given 3NOP gained more weight than the control animals.
Although larger, longer-term studies are needed, the findings are certainly promising, and if they can be implemented on a large-scale, the potential to reduce emissions could be significant.
[H/T: Science Magazine]