Written by: Girik Narang, Sambhav Athreya, Tanvi Donepudi, Sharana Sabesan Contact: [email protected]
<aside> 💡 In California alone, 750,000 tons of methane gas are released annually due to enteric fermentation induced by traditional cow feeds.
</aside>
Problem: Emissions from ruminant livestock in California are responsible for ≈40% of the state's total methane emissions
In 2013, California launched the climate pollutant reduction strategy to decrease CH4 livestock emissions by 40% before 2030. Despite some progress being made, 750,000 tons of methane are still released annually due to enteric fermentation, making up just under 40% of total methane emissions state-wide. Given the current rate of methane emissions, decreasing livestock emissions by 40% within the next decade proves a difficult task.
Recommendation: Supplementing cow feed with Asparagopsis taxiformis (red algae) to reduce enteric methane
Investing 28% of the US Department of Energy's $5 billion budget towards commercializing and scaling Asparagopsis production will reduce total methane emissions by 80%. not only create opportunities for cattle farmers, but it will enable an ecosystem of success for algae farmers, livestock producers, transporters, processors, and exporters. Most importantly, just adding 5g of red algae to 1kg of cow feed has the capacity to cut total enteric methane emissions by 80%, bringing us one step closer to being carbon-neutral by 2035.
Methane is a potent GHG, the emissions responsible for about 20 percent of the global warming now driving climate change. Although the state of California launched the climate pollutant reduction strategy (SB 1383; CARB 2017) intending to decrease CH4 emissions from livestock by 40% by 2030, it fails to address the fundamental problem with ruminant animals. Over half of the methane emissions in California come from dairy/livestock manure and enteric fermentation (the latter mostly from burping).
The majority of cow feed is derived from grass, molasses, corn, and a mixture of grains. Beef farms usually consist of more pasture as beef cattle have a primarily grass-based diet, whereas dairy animals have a higher grain-based diet. While both these feeds are somewhat economically viable and accessible, the environmental effects are dreadful. The issue with this cow feed is less concerned with the actual quality or type of feed and more with how the animal digests and processes the food. A cow has four stomachs, and methane production takes place in the first stomach, which is known as the rumen. In the rumen, there are microbes called methanogens, which bind with vitamin B12 to digest food. However, as a byproduct, they produce a ton of methane which is emitted out through the mouth. This process is called enteric fermentation.
The most direct way to prevent methane emissions would be to take vitamin B12 away from the methanogens by binding to them. Vitamin B12 is a cofactor needed by methanogens to create methane. By taking Vitamin B12 out of the equation, these microbes cannot undergo enteric fermentation; therefore, no methane is created.
There have already been a lot of excellent evaluations of enteric methane mitigation methods. Recently, we've seen several methods for lowering CH4 emissions through enteric fermentation and manure management, including diet manipulation, feed additives, anaerobic digestion, and liquid-solid separation. Similar to this, other reviews list mitigation strategies for lowering CH4 emissions from manure management. However, the evaluations need to provide a quantitative and comprehensive assessment of the effects of feed and manure additives.
Startups in this field: