Methane Production from Factory Cattle Farming

Informative Speech

GP: to inform

SP: to inform my audience about how cows produce methane

CI: Cattle produce methane through fermentation in their digestive process, levels varying based on factors such as their diet, and their manure when stored in anaerobic lagoons, all the while their production is subsidized by the government thereby encouraging more methane emissions. 

Introduction

(Attention Getter) 

1. The United States Environmental Protection Agency (“Overview…”) has a website overviewing methane emissions, which states livestock and manure management combine to be “the largest source of methane emissions in the United States;” in 2018 these sectors contributed to thirty-eight percent of the total. 

(Relate Topic to the Audience)

2. This is important because despite its shorter lifetime in the atmosphere than CO2, according to the EPA, “Pound for pound, the comparative impact of CH4 [methane] is 25 times greater than CO2 over a 100-year period (“Overview…”),” so that means the more methane we emit the more efficiently we pollute our atmosphere and contribute to climate change. 

1. I’m sure you're all aware of carbon dioxide’s impact on global warming, and clearly methane is far worse. 

2. Therefore, it is important to understand the relationship between cows and methane.

(Credibility)

3. Personally, I like to spend my time researching various causes of climate change, how they happen, and how to prevent them. 

1. Beef and dairy cows have become a recent focus of mine. 

2. In addition, I have now read several articles and watched several videos on digestive fermentation, feed options, manure management, and meat and dairy subsidies.

(CI) - Cattle produce methane through fermentation in their digestive process, more or less depending on their diet, and via their manure when it is stored in anaerobic lagoons, all the while cattle production is subsidized by the government.

Transition: The methane production process that is innate to cattle is fermentation that occurs in the first of their four stomachs, the rumen, as a part of digestion.  

Body

1. When cows digest their food, especially grass, a process called enteric fermentation is involved. 

1. In order to break down and digest cellulose the enzyme cellulase must be present. 

1. However, no mammal produces cellulase, therefore it has to be brought in by microorganisms (Elsden). 

2. These microorganisms in the rumen are then able to break down cellulose into glucose (A). 

2. This is then fermented in the anaerobic environment of the stomach and broken down into volatile fatty acids (VFA), namely propionic and butyric acids. 

1. The VFAs can then be absorbed and used by the cow. 

2. It is also during this fermentation process that hydrogen and carbon dioxide are produced as a by-product which other microorganisms, methanogens, take and produce methane, which is then released from the cow primarily by cow burps (Haque). 

Transition: Another aspect to consider while looking at their digestion process is to look at how their diet affects methane production. 

2. Grass is the natural food for cattle, but because it is more difficult to digest than grain, and more grass is needed to provide sufficient energy and nutrition, when grass is their only feed source they end up producing more methane and over a longer period of time.  

1. But if the grass fed to them is young, then it's easier for cows to digest and therefore relatively reduces methane emissions compared to if the grass were more mature (Haque). 

2. It should be recognized though, the net greenhouse gas emissions from cows eating grass is comparatively lower than cows eating grain.

1. If cows are rotated on pasture land, their nibbling promotes new growth, their stomping works manure into the soil, and the grass and soil provide a significant carbon-sink.

2. Grain production on the other hand, uses fossil-fuel based fertilizers, pesticides and transportation (Farms).

Transition: And when the non-digestible feed comes out the other end, what does that mean for methane production? 

3. In factory farming operations, manure is often stored in lagoons, which are outdoor earthen basins.

1. These are anaerobic systems meaning they do not have access to oxygen, therefore as the manure is decomposed methane is produced (Mangino). 

1. Methanogens are microorganisms that convert by-products of initial decomposition, carbon dioxide and hydrogen, into methane (Li). 

2. However, in an aerobic environment, oxygen inhibits the growth of methanogens.

2. Therefore, restricting manure to an anaerobic environment produces more methane than if it were spread out over a greater area of land (Peter).

Transition: Finally, it is worth considering how the volume of cattle raising got to be where it is today, at least in the United States.

4. Currently our government continues to directly and indirectly subsidize meat and dairy farming. 

1. Besides directly, two indirect ways they subsidize these industries is through grain subsidies and manure maintenance subsidies.

1. The government subsidizes them for their operations using tax dollars.

1. This is what drops the number on meat and dairy price tags. 

2. And this is instead of subsidizing fruits and vegetables (O’connor).

2. In the US 900 million acres are dedicated to corn, and most of the corn produced goes to livestock feed (Capehart). 

2. These subsidies were put in place to help alleviate farmer’s strain in the Dust Bowl and The Great Depression. 

1. They subsidized farmers to ensure supply did not exceed demand and so that their products would be profitable. 

2. However, the subsidies no longer serve their original purpose (Amadeo).

Transition: In summation, there are several variables associated with cattle farming’s methane production. 

Conclusion

(recap main points/thesis)

1. When cows digest their food, especially grass, a process called enteric fermentation is involved and a primary by-product is methane.

2. Cows that are also fed grain overall have a more significant environmental impact. 

3. In factory farming operations, once cows poop out the non-digestible waste, the manure is often stored in anaerobic lagoons leading to additional methane production.

4. And currently our government continues to subsidize meat and dairy farming. 

(bang)

5. Even with all this waste created and resources put into these operations, the Environmental Working Group’s website states, “Roughly 20% of all meat sold in the US winds up in the trash. That makes the pesticides, fertilizer, fuel and water used to produce and process it, as well as the resulting greenhouse gases and environmental damage, unnecessary and preventable” (Group). 

1. And when wasted meat is sent to the landfill, and becomes buried by other waste creating an anaerobic environment and enhancing methane production. 

2. Nearly the whole life cycle of the cattle industry causes methane emissions. 

Edit: Please also view this TEDx : It's not the cow, it's the how. (Savory Institute)

Works Cited

A, DIGICLASS. “Life Process:-Digestion in Ruminants-07.” YouTube, 20 Jan. 2017, www.youtube.com/watch?v=kK7IWjNYwxI.

Amadeo, Kimberly. “What Are the Major Federal Government Subsidies?” The Balance, 2020, www.thebalance.com/government-subsidies-definition-farm-oil-export-etc-3305788.

Capehart, Thomas, and David W. Olson. “Feedgrains Sector at a Glance.” USDA ERS - Feedgrains Sector at a Glance, 26 Feb. 2020, www.ers.usda.gov/topics/crops/corn-and-other-feedgrains/feedgrains-sector-at-a-glance/.

Elsden, S.R. “Ruminant Digestion.” Annual Reviews, 1948, www.annualreviews.org/doi/pdf/10.1146/annurev.bi.17.070148.003421.

Farms, Silver Fern. “Grain-Fed Beef vs. Grass-Fed Beef – Greenhouse Gas Emissions.” New Zealand Meats, 2011, newzealmeats.com/blog/grain-fed-vs-grass-fed-beef-greenhouse-gas-emissions/.

Group, Environmental Working. “Waste.” Waste - 2011 Meat Eaters Guide | Meat Eater's Guide to Climate Change + Health | Environmental Working Group, 2011, www.ewg.org/meateatersguide/interactive-graphic/waste/.

Haque, Najmul. “Dietary Manipulation: a Sustainable Way to Mitigate Methane Emissions from Ruminants.” Journal of Animal Science and Technology, 2018, janimscitechnol.biomedcentral.com/track/pdf/10.1186/s40781-018-0175-7.

Li, Changsheng, et al. "Manure-DNDC: A Biogeochemical Process Model for Quantifying Greenhouse Gas and Ammonia Emissions from Livestock Manure Systems." Nutrient Cycling in Agroecosystems, vol. 93, no. 2, 2012, pp. 163-200. ProQuest, http://ezproxy.canyons.edu:2048/login?url=https://ezproxy.canyons.edu:2457/docview/2259661045?accountid=38295, doi:http://ezproxy.canyons.edu:2069/10.1007/s10705-012-9507-z.

Mangino, Joseph, et al. “Development of a Methane Conversion Factor to Estimate Emissions from Animal Waste Lagoons.” Environmental Protection Agency, 2001, www3.epa.gov/ttn/chief/conference/ei11/ammonia/mangino.pdf.

Mitchell, Peter. “The Use of Cow Manure for Fertilizer.” Home Guides | SF Gate, 21 Nov. 2017, homeguides.sfgate.com/use-cow-manure-fertilizer-43702.html.

O'connor, Anahad. “How the Government Supports Your Junk Food Habit.” The New York Times, The New York Times, 19 July 2016, well.blogs.nytimes.com/2016/07/19/how-the-government-supports-your-junk-food-habit/.

“Overview of Greenhouse Gases.” EPA, Environmental Protection Agency, 10 Apr. 2020, www.epa.gov/ghgemissions/overview-greenhouse-gases.