Are There Practical Solutions To Methane Emissions From Cattle?

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Today is the 4th of July in the US. Around the country people will be firing up their grills and eating juicy hamburgers. Few party-goers, though, will think about the methane emissions that result from vast herds of US factory farmed-cattle.

Scientists have been trying for years to find just the right formula to reduce methane emissions from cattle. What — you don’t know about cows and methane emissions? I’ve always been an advocate of slowing down science just a bit so regular folks like us understand the big picture. Then we can absorb the smaller details. So here goes.

Cattle digest food differently than humans do. They can consume foods such as grasses and hay, which move through their digestive system in a cycle known as the biogenic carbon cycle. This cycle is in constant rotation, using the least energy possible. Methane molecules are produced as the rotation takes place. The methane is belched out the front end of the animal and is a by-product of the manure they excrete.

In the simplest terms, methane emissions are the gases produced by ruminate animals such as cattle as they burp and poop.

We now know that the overproduction of cattle and the methane emissions they produce are a serious problem for the planet. Methane is a potent greenhouse gas (GHG) with a global warming potential 21 to 26 times greater than carbon dioxide (CO₂). It’s a significant driver of climate change.

To prevent worsening and potentially irreversible effects of climate change, the world’s average temperature should not exceed that of preindustrial times by more than 1.5 degrees Celsius (2.7 degrees Fahrenheit). Rapidly reducing methane emissions from energy, agriculture, and waste is regarded as a most effective strategy to keep the goal of limiting global warming to 1.5˚C within reach. It will also add in other benefits like improving public health and making agriculture more productive.

Sources of GHG from livestock production include methane emissions, manure, feed production, land use change, energy, and processing. There have been many promising strategies for mitigating methane emissions (enteric CH₄) across various ruminant livestock species — cows, sheep, and goats.

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Enteric CH₄ comprises 17% of global CH₄ emissions and 3.3% of total GHG emissions. In 2021 the Global Methane Pledge inspired more than one hundred and fifty countries to reduce global methane (CH₄) emissions by at least 30% of the previous year’s levels with a 2030 target.

The simplest pathway to that goal would be for humans to stop eating beef products; I haven’t had red meat since 1980. But that’s unlikely for the mass population. So, if factory farms reduce enteric CH₄ emissions from ruminant livestock, it could really be a key intervention to alter the GHG emissions associated with food production.

Solutions Start with the Food That Cows Eat

Cows’ natural diet consists mainly of grasses, legumes, alfalfa, clover, and hay. They are grazing animals, after all. The average cow eats 2% of their body weight a day, which averages out to 24-26 pounds of food.

But cows on factory farms are fed inexpensive and unsustainable animal feed, such as corn and soy — it’s all about the profits, stupid, not the planet. Dried distillers grain (DDG) has become the number one source of protein used in cattle feedlots.

DDG is a co-product of the dry-grind fuel ethanol production process. The majority of US ethanol production is from dry-grind technology in which the whole corn kernel is ground and mixed with water and enzymes. The mash is cooked to liquefy the starch further and cooled. Then it is mixed with more enzymes to convert the remaining sugar polymers to glucose before fermenting to ethanol. The components of the kernel not fermented include the germ, fiber, and protein and are concentrated in the DDG that are produced as co-products.

Changing the composition of DDG animal feed can help to solve the problem of methane emissions.

What would happen if factory farmers added whole cottonseed to cattle feedstocks? One study this year by South American researchers evaluates the effects of whole cottonseed (WCS) supplementation on CH₄, dry matter intake (DMI), and performance in beef heifers fed low-quality forage diets. Results demonstrated that WCS supplementation reduced CH₄ emissions by 29% (g/day) and CH₄ yield by 22% (percentage of gross energy intake) compared to a forage-only diet. Methane emissions reductions of nearly one-third? That’s pretty good, right?

Feed additives containing bromoform (CHBr3) showed promise in a separate 2025 study. Bromoform produced minimal impact on animal production parameters. RuMin 8™ is a patented, unique blend of highly soluble dairy sugars and organic acids that enhance microbial activity improving energy and protein availability in ruminants. Its ingredients are typically dried whey product, malic acid, soy flour, dried corn syrup, maltodextrins, dextrose, vegetable fat, and artificial flavor. The Rumin8 oil treatment in the study led to a significant reduction in methane emissions, with a ≈95.0% decrease in methane production, yield, and intensity — without any negative effects on the animals’ growth or their digestive health.

Does Treating the Manure Ponds Help Reduce Methane Emissions?

Once cows are milked, their sheds are hosed down to wash away cow manure into large human-made ponds, called lagoons. In New Zealand, local scientists tried to recycle the water in the lagoons with the addition of polyferric sulfate. That’s a chemical that’s been widely used in wastewater treatment to separate liquids from solids.

They came up with some very interesting results.

Adding polyferric sulfate decreased methane emissions from the wastewater by more than 90%. As described in a Bloomberg exposé, the result was a sharp drop in the powerful GHG that cattle farmers have been trying to tame for years.

How did this happen? Scientists Keith Cameron and Hong Di changed the lagoon’s balance in favor of sulfate-reducing microorganisms. Sulfate reduction is a type of anaerobic respiration, and it started to outcompete methanogens in the lagoons. Methanogens generate methane, are plentiful in cow poop, and grow considerably in effluent ponds.

The process that Cameron and Di created is quite easy to follow. To treat a lagoon full of cow poop, the pond liquid is sucked into a pump on a truck. It moves through a manifold, where it is mixed with polyferric sulfate and sulfuric acid. When that part is done, the slurry is deposited back in the lagoon. The process typically takes a few hours and is repeated every six to eight weeks.

This new methane emissions solution is being disseminated in a New Zealand pilot program to about 250 farms under the name EcoPond.

While the initial pilot is focused on farms raising cows, the approach has “broad applicability across various methanogenic environments — such as rice paddies, wetlands and similar systems,” says Marcelo Mena, chief executive officer at the Global Methane Hub. The Hub is building a global network of scientists, experts, activists, policymakers, and philanthropists to push toward the single goal of mitigating methane.