Through a collaborative project at the University of Wisconsin-Madison College of Agricultural and Life Sciences, Francisco Peñagaricano and his research collaborators hope to play a role in reducing the methane produced by the 9.3 million dairy cattle across the country.

Peñagaricano, a native of Uruguay and an assistant professor in the UW-Madison Department of Animal and Dairy Sciences, is working with three other UW-Madison professors, as well as personnel from the University of Florida, Iowa State University, Michigan State University and USDA, to study how to minimize enteric methane production in dairy cattle. Enteric methane is a byproduct of the natural digestive process occurring in ruminant animals such as cattle, goats, sheep and buffalo, primarily in the form of belches.

Peñagaricano and his collaborators received a $2.3 million grant from the Greener Cattle Initiative — a multi-partner international consortium investing in research mitigating enteric methane — and an additional $1 million from the Council on Dairy Cattle Breeding to work on the three-year research project.

Joining Peñagaricano from UW-Madison in the project are Hilario Mantovani, an assistant professor in rumen microbiology, funded by the Dairy Innovation Hub; Heather White, a professor in nutritional physiology; and Kent Weigel, chairman of the Department of Animal and Dairy Sciences and a professor in breeding and genetics.

Reducing methane emissions

The project’s goal is to mitigate enteric methane emissions from dairy cattle by combining selective breeding, milk mid-infrared spectra data and rumen microbiome interventions. Researchers will measure methane emissions, feed intake, energy-corrected milk, body weight and milk mid-infrared spectra for six to eight weeks in 4,000 midlactation Holstein cows.

The original plan was to house the cattle on six research farms across the four states involved in the project, but the collaborators have since decided to expand the research to commercial dairy farms as well.

“At research stations, we can measure not only methane emissions but also the amount of feed that each cow eats every day,” Peñagaricano says. “We are not able to measure exactly how much a cow eats per day on a commercial farm, but it’s good to have commercial farms involved in this project, because you are closer to the next step in implementation.”

In Wisconsin, 128 cows are currently being phenotyped at the Arlington and Marshfield agricultural research stations.

Researchers will be able to measure methane emissions with the help of a contraption called a GreenFeed System. The portable feeding bins capture all the air exhaled by the cow while she is eating and deliver a reliable estimate of methane emissions for that individual cow. The researchers currently have seven GreenFeed units in place, each with a cost of nearly $120,000, including the monitoring equipment.

Some cows emit more methane than others, so researchers will try to determine why that is and how genetic selection can be used to breed for animals that produce less methane.

“That is how genetic selection works,” Peñagaricano says. “The next generation will emit a little bit less than the one before, and so on and so forth.

“A Holstein cow produces more than twice as much milk today as compared to 60 years ago, and 60% of that change is due to genetic selection. It is an extremely powerful tool that in the long term is very cost-effective. It is the best way we have to change the performance of the population.”

Milk testing

The second prong of the project explores milk testing. Most farmers send monthly milk samples to a lab to monitor quality and get a reading of protein and fat levels in the milk. Project researchers would scan milk samples with infrared light to identify specific chemical compounds, with a goal of developing a low-cost, noninvasive tool that farmers could potentially use. This approach would also increase the accuracy of genomic breeding values.

Peñagaricano says if farmers know which cows are emitting more methane and which are emitting less, they can target the high-emitting cows with interventions such as specific diets to minimize the emissions.

Research also will work to develop tools to manipulate the rumen, where methane-producing bacteria are found. Using emissions data from the GreenFeed units, the research team will identify the highest and lowest methane-producing cows and sample their rumen microbiomes. The sampled microbiota will be evaluated for differences, ahead of testing the impact of microbial or dietary interventions.

COW EMISSIONS: GreenFeed units at the UW-Madison Agricultural Research Station in Arlington, Wis., measure cow emissions. (Maria Woldt/Dairy Innovation Hub)

Peñagaricano, designated as the research project’s primary reviewer, says it’s clear the dairy industry needs to address the problem of methane emissions. Methane represents 11% of total U.S. greenhouse gas emissions — the second most important greenhouse gas after carbon dioxide — and the methane produced by ruminants accounts for 27% of methane emissions. Officials estimate that methane remains in the atmosphere for about 12 years.

Methane and carbon dioxide are both greenhouse gases that contribute to global warming.

The four universities and USDA have been working together since 2009 on dairy cow feed efficiency that is now enabling dairy farmers to obtain feed-efficiency breeding values for their cows. “Feed Saved” was added in December 2020 as a trait in the Council on Dairy Cattle Breeding’s Net Merit Index.

Methane emissions research is closely related to feed efficiency, Peñagaricano says, and the new collaborative study was the natural next step.

The collaborators are meeting as a large group every two months, and the internal UW-Madison researchers are meeting every month, Peñagaricano says. The project is scheduled to last three years, but he says a schedule extension is possible.

The Greener Cattle Initiative includes stakeholders from across the dairy and beef industries. The stakeholders’ aim is to provide climate change solutions that benefit producers, animals and the environment.

Peñagaricano’s wife, Jimena Laporta, is also a faculty member within the Department of Animal and Dairy Sciences. She is an assistant professor with a specialty in lactation physiology. They live in Middleton, Wis., with their two children.