By Jeanne Yacoubou, MS

In our recent article on the carbon footprints of vegan pizza vs. meat pizza, we mentioned that the major agricultural source of methane is bovine: belching beef cattle and dairy cows ruminating on forage or feed. During their lifetime, each animal burps out roughly 220 pounds of methane, comparable to the carbon emissions from burning 900 gallons of gasoline. As a whole, ruminants contribute 30% of all anthropogenic methane emissions. Since methane is a short-lived greenhouse gas – compared to carbon dioxide – the fastest way to reduce global heating is to cut methane as soon as possible.

And as countries, like dairy-dominant New Zealand, start charging a carbon tax for animal-caused methane emissions in 2025, the race is on to cut methane out of animal agriculture.

So, what are some of the ways that animal scientists propose to limit bovine methane production? Here’s a brief rundown.

1. Adding certain substances to animal feed, like seaweed or 3-nitroproxypropanol, has been shown to reduce methane production in bovines. This research is a long way from being used on an industrial basis because neither compound has federal approval to be used as a feed additive. That process usually takes years. Plus, huge amounts of energy are required to grow the seaweed commercially. The cost of this energy could offset any benefit seaweed has for reducing global heating caused by bovines.
2. Low-methane breeding research aims to create bovines that produce less methane. In fact, the first commercial sale of genetically altered semen this year could be a game changer if it doesn’t have any unforeseen negative consequences like digestive problems or slower weight gain. Unfortunately, low-methane selective breeding is predicted to result in only a 1.5% reduction in methane emissions. And if the low-methane animals need more time to fatten up to market weight, it could become costly to keep the animals alive longer. So, for economic reasons, farmers may opt out until low-methane genetic breeding proves itself to be commercially viable.
3. Since the gut microbiome actually churns out the methane – not the bovines themselves – vaccinating animals against the gut microbes (methanogens) appears to be a strategy to reduce agricultural-sourced methane. Still new on an experimental basis, it’s unknown whether this method will work in the long-term. Altering the gut microbiome – the seat of the immune system – could have far-reaching consequences that prove to be too risky.
4. Virtual fencing using GPS tags to keep cattle enclosed where you want them is a new technology that doesn’t suffer from the need to install, repair, or replace physical fences. Researchers are experimenting with using this method to move grazers rotationally from plot to plot where there’s less dry, older grass and more new grass. This strategy is based on the idea that cattle eating young grass produce less methane. According to the Food & Agriculture Organization, grazing ruminants (mainly cattle and sheep) produce 47% of agricultural methane, so decreasing it through modified grazing practices would be climate-friendly.

This method may work for small ranchers with enough land and a small herd. However, on a commercial basis, it’s doubtful that virtual fencing could be a long-term solution for methane reduction. Moving hundreds of cattle, possibly from state to state, to get to young grass, would be a logistical nightmare. Not to mention expensive.

Given the long-running heatwave in Texas, a major cattle-rearing state, companies would need air-conditioned trucks to transport animals or suffer from high fatality rates. Economic losses – either from fuel costs or high mortality – would outweigh any benefit from whatever reduction in methane could result.

So what’s the fastest, most inexpensive way to reduce methane from cattle and cows that we know of?

The only way to cause an immediate and permanent end to methane production from bovines is to end the meat and milk industries that are based on cattle and cows.

Since a recent climate modeling study published in July 2023 concluded that if methane reduction occurs this decade – along with decreases in CO₂ emissions – global heating would be limited to “well below” 2 °C above pre-industrial levels. However, if methane reduction is delayed until the 2040s, a 2 °C breach will likely occur.

In light of the serious climate breakdown effects witnessed daily around the world at only 1.2 °C, it’s critical that methane emissions drop immediately. For ourselves and for future generations.

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