There’s a farm in the little town of Arlington, 20 miles north of Madison, that looks and smells like any other Wisconsin dairy operation. Its 550 cows are milked twice daily, once before dawn and again in the afternoon, like they are at thousands of dairy farms across the state. 

But at this farm — the University of Wisconsin’s Agricultural Research Station — when a cow eats, gets milked and burps, a data point is created. That data collection is helping researchers at UW-Madison adapt Wisconsin’s herd to the challenges of climate change. 

The agriculture industry produces 10% of America’s greenhouse gasses, a portion of which is enteric methane, a gas created throughout the digestive process of a ruminant animal — or gas created in the stomach of a cow and released when it burps, breathes, or flatulates. Methane is a “powerful” greenhouse gas and is the second-largest contributor to climate warming after carbon dioxide, according to NASA.

That means a climate-harming gas is coming out of the mouths and rears of the animals that make Wisconsin America’s Dairyland and enable its 5,000-plus farms and a $45 billion industry to exist. For the future of the state’s culture, industry and environment, researchers at UW-Madison are trying to figure out how to help farmers feed and breed cows to emit less methane.

A very powerful tool

In the barns of the Arlington farm are machines called “GreenFeed,” plastic and metal contraptions that sit in the corner of the dairy cattle’s pens. When a cow visits the GreenFeed, she’ll get a serving of alfalfa pellets — cow candy — every 40 seconds. While she snacks, the machine vacuums up the air she’s breathing and burping to measure the amount of methane emitted.

That data will be analyzed alongside the various other details collected — how much food she eats, her weight, how much milk she produces, the components and quality of that milk, etc. — to eventually determine which dairy cattle traits ensure a healthy, high milk-producing, low methane-emitting animal.

“What we are doing right now is trying to develop the tools so we can reduce methane emissions using selective breeding, using genetic selection,” said Francisco Peñagaricano, professor of genomics at UW-Madison’s Animal and Dairy Sciences department.

“The idea is (that) in every generation, you identify the best parent for the next generation,” he said. “If I have two cows that produce exactly the same amount of milk and they have the same body weight, but there is a cow that is producing less methane than the other one, you say … ‘You produce less. I prefer you.’”

Genetic selection has the power to change the physical and biological makeup of Wisconsin’s dairy herd over time. UW-Madison, along with three other universities across the nation and the USDA, are collaborating in a research effort to identify which traits make a bovine emit less methane and how to incorporate that into farmers’ breeding process.

Peñagaricano called it a “multi-institutional, multi-disciplinary effort” and is confident there will be results to share with farmers in two years.

“Maybe I’m biased because I’m a geneticist,” he said. “But I am convinced genetic selection plays a key role when we think about sustainable dairy farming.”

Part of his confidence comes from the fact that this type of work has been done before. Over the last 60 years, researchers and farmers have been breeding cows to produce more milk, to live longer, to be in better health and to use their food more efficiently.

The dairy cow of today produces more than twice as much milk as the dairy cow of 60 years ago, Peñagaricano said, and the majority of that change can be attributed to genetics.

“The changes that we can achieve through genetic selection are cumulative, permanent and incremental,” he said. “(That’s) what makes genetic selection a very, very powerful tool.”

It’s been done before

Each cow at the agriculture research station has an identification tag on its ear. When the animal approaches the manger full of corn silage, the monitor on top of the machine recognizes which cow it is and starts to collect data specific to that animal.

The cows adapt to the foreign technology in their environment and learn how to use the research devices within two to three days, Peñagaricano said. “It’s a very smart beast.”

The tub of feed is weighed before and after the cow’s meal, identifying down to the ounce how much she ate. It also knows how long she spent eating, a relevant piece of information because how fast a cow eats is a heritable trait, meaning that researchers can actually breed a cow with better table manners.

“My grandma used to tell me, ‘Francisco, eat slowly,’ and this is exactly what we found. Cows that eat faster tend to be less efficient,” Peñagaricano said.

Feed efficiency is a metric farmers and researchers breed for that ensures a cow is able to produce the maximum amount of milk on a certain amount of food. Ultimately that efficiency results in less greenhouse gasses emitted per pound of milk; less feed needed means less land used and crops cultivated.

For years farmers have been using the information learned in previous genetic studies. In 2020, researchers developed a national genetic evaluation so farmers can breed for traits that make cows more efficient users of feed.

Similarly, over the last few decades researchers and farmers have developed sophisticated metrics for breeding cows with the best milking qualities. Milk high in fat and protein makes great cheese, traits relevant to many farmers and processors in Wisconsin.

In the 1970s, dairy producers bred for a few traits, mostly just quantity and quality of milk. Dairy genetics have come a long way since then, Peñagaricano said, allowing farmers to select for many others. 

The amount of methane a cow releases is as heritable of a trait as milk production is, Peñagaricano said. The success researchers have had in breeding for milk production and feed efficiency is in part what makes Peñagaricano confident that in a few years, they’ll be able to add methane emissions to the index. 

“If we are able to start to select for methane emissions, believe me, we will reduce methane emissions in our cows,” he said.

Feed additives to lower methane emissions

Luiz Ferraretto has loved working with animals ever since he was a kid spending time on his family’s small dairy farm in Brazil.

“It was a no-brainer that (studying) dairy cows and how they eat is what I wanted to do for a living,” he said.

Ferraretto is also conducting trials at the Arlington research farm aimed at understanding and reducing dairy cow methane emissions. He is a professor of ruminant nutrition at UW-Madison and an expert in the dairy cow diet that enables the animal to produce many pounds of milk each day.

“A lactating dairy cow, she’s like an athlete going to the Olympic Games,” Ferraretto said. The bovine athletes need a lot of nutrients and calories to make milk.

Whether feed additives — a supplement in the cow’s food — can reduce the methane emitted by a dairy cow while maintaining a robust level of milk production is the question Ferraretto and other ruminant nutritionists are exploring.

There are some promising options, and Ferraretto called it a “hot topic” in dairy nutrition research right now. Mixing seaweed in a cow’s diet has been shown to reduce the amount of methane the animal produces, but the cost/benefit analysis of the carbon emissions associated with harvesting and transporting seaweed has been debated. A variety of fatty acids and 3-NOP — an additive usually in powder form — included in dairy cattle feed have also shown promising results.

Both Ferraretto and Peñagaricano keep farmers front of mind throughout their research. They want the information gathered to be relevant and viable to Wisconsin farmers.

Ferraretto and his students are analyzing the cost of feed additives for a farmer. Profit margins in dairy are slim. Farmers usually have to invest in a lot of equipment and technology to operate a dairy, meaning any additional cost will be scrutinized.

If a feed additive reduces methane emissions but also has a negative impact on milk production, it’s likely a no-go for farmers.

“I’m not saying that we should not take care of the environment. All I’m saying is, we have to be careful because with milk prices being (as) low as it often is, it gets quite difficult,” Ferraretto said.

A proactive step

The research exploring how to lower methane emissions in dairy cows is being conducted on Holstein dairy cows — the breed that makes up the majority of the milking cows in the U.S. — and if successful will be adapted to others.

Peñagaricano’s work is supported by the Greener Cattle Initiative and the Council on Dairy Cattle Breeding, a nonprofit that tracks genetics in the dairy herd and works “to provide tools that farmers can use to basically create the next generation of more sustainable, more productive and healthier cows,” said outreach specialist Katie Schmitt.

This type of feed and genetic work was “a proactive step” on behalf of the dairy industry, Schmitt said. Because of the climate crisis, it’s likely that farmers in the future will be asked to address the amount of methane their herds produce.

The Council on Dairy Cattle Breeding gives dairy farmers a metric to breed for characteristics relevant to their farm’s goals. Those traits can include, “cows that are healthier, cows that produce more, cows that live longer, cows that are more feed efficient, and we hope in the future through Francisco’s work, cows that are producing less enteric methane,” Schmitt said.

This economic evaluation is important in helping the dairy industry move toward more environmentally sustainable practices, she said. Sustainability, she said, is a three-legged stool. 

“Environmental sustainability is important. Obviously, we know that, but it has to be balanced with economic and social sustainability as well,” Schmitt said. “So to tackle one without the other two, you’re going to have a stool that falls over.”

Jordan Matthews is a partner at Rosy Lane Holsteins, a dairy farm in Watertown that regularly participates in research trials, including Peñagaricano’s work with the GreenFeed machines.

“We get 35 data points collected every time a cow is milked, from milking speed to quality of milk to quantity of milk, where they got milked, what time they got milked, etcetera,” Matthews said.

“Certainly we’re always interested in — What are our cows doing? What are things that we’re not measuring today, that potentially or hopefully, we can get better at?” Matthews said.

Methane emissions are one of those factors. Rosy Lane Holsteins breeds its dairy cows for feed efficiency, longevity and health.

“Feed is our biggest cost of production on a dairy farm, so we want as much of that feed to turn into milk as possible,” Matthews said.

Agriculture sustainability is again top of mind as governments and private industry look for ways to reduce greenhouse gas emissions amid the climate crisis. But for dairy farmers, efficiency and sustainability are never far from mind, Matthews said. Rosy Lane Holsteins has been doing this work for a long time.

“So now we have to back it up with science.”