Greener Cattle Initiative Awards

Penn State’s Distinguished Professor of Dairy Nutrition, Dr. Alexander N. Hristov, is developing new enteric methane inhibitors, naturally occurring or synthetic compounds that, when ingested by cows, can decrease enteric methane emissions. The research also assesses the most effective delivery methods for these inhibitors.

The research team is focusing on inhibitors that have already been shown to reduce methane by at least 30% in laboratory tests and studying the efficacy and feasibility of these inhibitor compounds in cows. Additionally, they are identifying and optimizing dietary conditions required to maximize enteric methane emission reductions.

Goals & Objectives

1. Complete and summarize the data from preliminary laboratory work with promising enteric methane inhibitor compounds.
2. Test the most effective inhibitor(s) from the preliminary laboratory work on lactating dairy cows to collect methane mitigation data, as well as measure the effects of the inhibitor(s) on lactational performance, milk fatty acid profile, ruminal fermentation and microbiome, nutrient digestibility and blood chemistry.
3. Test the most effective inhibitor(s) from the preliminary laboratory work on lactating dairy cows to measure long-term effects of treatment on enteric methane emission, rumen fermentation and microbiome, lactational performance and animal health and present these findings at scientific conferences and in peer-reviewed journals.

All cows produce methane, but not every cow is alike. According to preliminary research conducted by Dr. Francisco Peñagaricano, assistant professor in the University of Wisconsin–Madison Department of Animal and Dairy Sciences, and his team, some cows release around 600 grams of methane per day, while others average around 300 grams. This result informs the selective breeding of U.S. dairy cattle that release lower methane emissions.

Peñagaricano, the project’s principal investigator, is leading a research team that includes three faculty members in the University of Wisconsin–Madison Department of Animal and Dairy Sciences: Dr. Kent Weigel, who focuses on breeding and genetics, Dr. Heather White, who studies nutritional physiology; and Dr. Hilario Mantovani, who specializes in rumen microbiology.

The team is taking a three-pronged approach to reducing enteric methane emissions.

1. Using genetics to selectively breed cattle that produce fewer methane emissions.
2. Developing a milk-based test to predict a cow’s methane emissions.
3. Understanding microorganisms in cows’ rumen, a large fermentation vat in the first compartment of cows’ stomach, is necessary to inform possible dietary or other interventions.

Genetics

First, the research team is measuring how much methane 4,000 individual Holstein cows exhale using portable GreenFeed systems that capture all the air a cow exhales while eating. The team will then study the genetics of these cows, identifying various traits, such as the quantity and intensity of methane production. Once these traits are better understood, the team can pursue selective breeding for cows that produce less methane.

Milk Testing

The second prong of the project is developing a low-cost, noninvasive tool that farmers can use to measure herd methane emissions. The research team is using milk spectrometry technology to explore whether infrared light can identify specific chemical compounds in the samples that would indicate methane emissions. Dairy farmers usually send monthly milk samples to a lab to monitor overall quality, protein, and fat levels. The research team further aims to test their tool on these milk samples to inform farmers about their herds’ methane emissions.

Understanding Rumen Microbes

The third prong of the project focuses on better understanding the relationship between the rumen, the microbes that live within it and methane production, as well as how diet or genetics impact them. Using GreenFeed systems’ emissions data, the team is identifying the 10% highest and lowest methane-producing cows from the 4,000 tested and examining their rumens and microbes within to determine differences. The data will be used to inform future dietary methane-inhibiting intervention research strategies, like inserting specific bacteria into the rumen before lactation to reduce enteric methane.