What are some of the most famous natural places in the United States? The Everglades and Yellowstone are two that come to mind. You may not know this, but their pine and mangrove forests store an immense amount of carbon. How about the Great Plains?.
Bisons and cows are both ruminant mammals, which means they digest food and make methane. But people are still arguing about whether bison or cows produce more, less, or about the same amount of methane. This article will look at the research that has been done to see if bison really do give off as much methane that changes the climate as domesticated cattle.
An Overview of Bison and Cow Methane Emissions
First, it’s important to understand why bison and cows produce methane in the first place.
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Both bison and cows are ruminants, meaning they have a 4-chambered stomach and digest their food through enteric fermentation This microbial fermentation process results in methane being released
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The methane is mostly exhaled through belching or flatulence. A smaller amount can also be released through exhalation.
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Methane is a potent greenhouse gas trapping heat in the atmosphere. Reducing methane emissions can help mitigate climate change.
So do bison produce more or less of this methane than cows? There are several key factors to consider.
Factors That Influence Bison vs. Cow Methane Production
Several variables impact the levels of methane released by bison compared to cows:
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Diet – The methane output of ruminants depends heavily on what they eat. Grasses, forages, grains and supplements all influence methane to varying degrees.
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Digestibility – How well an animal digests its feed impacts enteric methane. Higher digestibility is associated with less methane.
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Foraging – Bison graze on native grasses while cows are usually fed cultivated crops. This leads to dietary differences that affect methane.
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Size – Larger ruminants tend to produce more methane. Mature bison can weight up to 2,000 pounds compared to 1,400 for cows.
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Genetics – Evidence suggests genetics influence the microbial makeup of ruminant digestive systems, impacting methane output. Domestic cattle genetics have changed over time.
With these factors in mind, let’s look at what the research says.
Studies Comparing Bison and Cow Methane Production
Several studies have investigated the differences in methane emissions between bison and cattle. Here are some of the key findings:
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A 2012 study estimated historic bison emitted around 29.7 Tg methane yearly across America’s Great Plains.
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In comparison, current methane emissions from cattle in the U.S. total around 121.7 Tg per year.
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A 1998 study found daily methane production was 30% lower in bison compared to domestic cattle when fed the same diet of alfalfa pellets.
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However, a 2021 paper notes bison eat a native forage diet which likely results in even less methane than the alfalfa diet used in the 1998 study.
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Models suggest** reintroducing bison** to their historic Great Plains grazing lands could reduce methane emissions from those grasslands compared to current cattle grazing.
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But other evidence indicates bison and cattle produce similar levels of methane based on body weight when raised on comparable diets.
The consensus is that bison likely generate slightly less methane than domesticated cows overall. However, the magnitude of the difference depends on the variables noted earlier. Diet and digestibility in particular play a major role.
Why Do These Methane Differences Matter?
Understanding how bison and cattle methane emissions differ has implications for ranching practices and mitigating climate change.
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Demonstrating bison produce less methane supports programs introducing them to restore native grasslands while lowering greenhouse gases.
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The dietary differences provide insight for developing cattle feeds to reduce methane, like increasing digestibility.
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Comparing genetics may lead to selective breeding of cows that naturally produce less enteric methane.
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All of these outcomes can make cattle ranching more sustainable and combat global warming in the process.
Can Bison Ranching Help Address Methane Emissions?
The evidence overall suggests judicious incorporation of bison alongside cattle ranching could lower methane outputs from grazing lands.
Bison ranching offers other ecological benefits as well. Bison’s grazing patterns better maintain native prairie plant communities compared to cattle. Their hooves till soil and their dung helps fertilize prairie.
However, bison only comprise around 400,000 head in North America compared to over 90 million cattle. So increasing bison to meaningfully reduce methane emissions faces challenges of scale and economics.
A balanced integration of bison and sustainable cattle ranching practices provides the most pragmatic path right now for keeping grasslands intact while feeding the world and battling climate change.
Key Takeaways on Bison and Cow Methane Emissions
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Current research indicates bison likely produce slightly less methane than domesticated cattle, but the amount depends on several variables.
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Direct comparisons under the same conditions show bison can generate around 30% less methane than cows.
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However, historic bison herds likely released substantial amounts of methane comparable to today’s cattle numbers.
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Introducing more bison alongside cattle ranching could potentially lower total methane emissions from grazing lands.
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Understanding the methane output differences provides insights for developing less gassy cattle through breeding and diet.
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While promising, bison are unlikely to completely replace cows for meat production to reduce methane.
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A mix of cattle ranching innovations and strategic bison reintroductions offer the most realistic methane reduction strategy.
So in answer to the question – yes, bison do seem to produce less methane than conventional cattle raising. But historic bison numbers didn’t eliminate methane emissions. A dual approach can utilize the best of both bovines to lower methane for the future of sustainable ran
Grassland Soils Store Vast Amounts of Carbon
Grasslands used to cover a lot of the central United States. Grasslands are the most threatened and least protected type of habitat on Earth—even more threatened than the Amazon rainforest. Native grasslands are not only incredibly diverse, but they are also very important in fighting climate change. Their natural beauty makes them easy to overlook. Only a little more than an hour from the Twin Cities metro area are remnants like Schaefer Prairie. Most of the land they lived on before Europeans came is now farmland.
It is very possible for the United States to help solve one of the world’s biggest conservation problems by protecting grasslands. In both North Dakota and South Dakota, it’s the top natural climate solutions opportunity. In Minnesota, it’s one of the best such strategies available.
Grasslands or prairies cover about 15% of North America today. Most are west of the Mississippi River. There are more than 500 different native plants, hundreds of species of birds and mammals, and a huge number of insects, including pollinators like bees and butterflies. At first glance, there may not seem to be much to see.
If you look a little deeper, you’ll see that the rich black dirt below the surface holds a huge amount of carbon. Prairie plants take carbon out of the air through photosynthesis, replacing it with oxygen. They then store this carbon in their roots, which can reach deep into the rich soil and reach up to 15 feet in some cases.
Other than the 20 National Grasslands that are owned by the government, most of the grasslands in the US are privately owned. Many of these lands could be turned into cropland for crops like corn and soybeans because of the way the market works. More carbon is released into the air when grasslands are plowed under. This makes it harder to stop the worst effects of climate change.
Different types of soil, topography, and other factors affect how much carbon is in an acre of grassland versus an acre of cropland. However, many studies have shown that turning grassland into cropland causes 30 to 40 percent of the carbon stored in the ground to be lost.
Protection of the top 10 percent of the remaining grasslands in the Missouri Coteau region of North Dakota and South Dakota would be the same as taking 2 5 million passenger vehicles off the road.
Fire and Grazing are Essential to Healthy Grasslands
Grasslands require a couple of things to keep them healthy and diverse: fire and grazing. Lightning strikes and fires started by Native Americans would sometimes sweep through the grasslands, putting out trees, brush, and weedy plants.
Historically, grasslands were grazed by bison and elk. They not only mowed the grass, but their hooves also stirred the ground, putting down seeds for native grasses, forbs, and dead plants to make room for new life. Their urine and manure made the soil better, and when they moved on to new pastures, they gave the prairie time to rest and heal. Bison and, less often, elk still do this important natural job, but the common cow also does it.
I know what you are thinking. We’ve all heard that cattle are bad for our climate because of the methane they produce. And this is true. Cattle do produce methane as do bison and other ungulates. Many efforts are being made to find a way to stop this naturally occurring gas from spreading so that it doesn’t add to global warming.
But cattle actually mimic what bison and elk did naturally and are needed to help maintain healthy grasslands. Ranchers move their cows from pasture to pasture, where they graze and improve the soil, which helps grasses and wildflowers grow. Running cattle keeps the grass side up and carbon in the ground—and out of the atmosphere. A lot of people also use controlled burns to help forbs grow and stop invasive plants from taking over.
Cattle are also the main way that grasslands get the money they need to stay wild, on the tax rolls, and in production. Simply put, cattle turn grass, which most people can’t eat, into meat, which many people can. And they help sustain grasslands both ecologically and financially.
Yes, cattle are the top source of methane emissions in the U.S.
Do cattle produce methane?
And this is true. Cattle do produce methane as do bison and other ungulates. This gas contributes to global warming and much is being done to identify a way to suppress this naturally occurring gas to mitigate those impacts. But cattle actually mimic what bison and elk did naturally and are needed to help maintain healthy grasslands.
How much methane does a wild bison eat a year?
The researchers found bison fed a diet of sun-cured alfalfa pellets emitted about 30 kilograms of methane each year, far less than the roughly 100 kilograms per year emitted by cattle. A 2021 paper says wild bison could have produced even less methane, noting that their diet on the prairie would involve eating forage that would lead to less gas.
Did bison release more methane than cows?
The implied claim here is wrong. While cows aren’t the biggest source of greenhouse gases, they do still release methane into the atmosphere. However, limited research suggests bison in the 1800s may have released a similar, though possibly lower, amount of methane than cattle today.
Do bison emit methane?
“Both bison and cattle emit a minority of methane from flatulence (‘farts’). Almost all comes from eructation (‘burps’). This is because bison and cattle are ruminants, and methane production in the anoxic [without oxygen] rumen is almost entirely emitted through the mouth,” Stoy told Lead Stories in an email received on August 4, 2023.