Burping Cows! Measuring Methane Emissions from Cattle

According to 2022 statistics published by the US EPA, enteric fermentation (a digestive pathway that produces gasses in the gut) by cattle accounted for around 3% of total US greenhouse gas emissions when converted to carbon dioxide equivalents. We spoke with Dr. Glenn Duff, from New Mexico State University to learn more about the research he and his team are conducting to measure gas fluxes and emissions from cattle in pursuit of improving efficiency and lowering emissions from this sector.

Relevant Links:

Greenhouse Gas Inventory Data Explorer from the US EPA

Clayton Livestock Research Center, New Mexico State University

Sustainable Southwest Beef Project

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Come Rain or Shine affiliate links:
DOI Southwest CASC: https://www.swcasc.arizona.edu/ 
USDA Southwest Climate Hub: https://www.climatehubs.usda.gov/hubs/southwest 
Sustainable Southwest Beef Project (NIFA Grant #2019-69012-29853): https://southwestbeef.org/ 

Transcript

Emile: Welcome to Come Rain or Shine, podcast of the USDA Southwest Climate Hub 

Sarah: and the DOI Southwest Climate Adaptation Science Center, or Southwest CASC, operated by the USGS. I'm Sarah LeRoy, Research Coordinator for the Southwest CASC. 

Emile: And I'm Emile Elias, Director of the Southwest Climate Hub. Here we highlight stories to share the most recent advances in climate science, weather, and climate adaptation and innovative practices to support resilient landscapes and communities.

Sarah: We believe that sharing some of the most innovative, forward thinking, and creative climate science and adaptation will strengthen our collective ability to respond to even the most challenging impacts of climate change in one of the hottest and driest regions of the world.

The contents of this podcast are for informational purposes only and should not be interpreted as endorsement for any of the products, technologies, or strategies discussed. 

Emile: Today, we're talking about measuring methane and other gas emissions from cattle and why this is important research in the context of a changing climate.

Specifically, we will be focusing on research related to the implementation of GreenFeed. This is a new turnkey system designed to measure gas fluxes of methane, carbon dioxide, oxygen, and hydrogen from individual animals. We will be interviewing Dr. Glenn Duff. Glenn serves as a professor in Animal and Range Science at the Clayton Livestock Research Center with New Mexico State University.

He also serves as the project director for the Sustainable Southwest Beef Project. Glenn's area of expertise is feedlot nutrition and health. And he has taught a variety of courses related to this project, including Applied Nutrition, Beef Production, Stocker Feedlot Management, and Dairy Production.

Glenn has also published over 80 peer reviewed articles on these subjects. Glenn, thanks so much for joining us today. Let's start off with a basic overview. You're using a highly sophisticated machine to measure gas emissions from individual cows. Can you tell us a little bit about how this works? 

Glenn: Yes, we purchased these GreenFeed machines from the Southwest Sustainable Beef Project that I'm the director on.

And what we have them set up is in two different pastures. And when the cows stick their head into the machine, we bait them to get them into the machine. And then when the cows stick the heads in, it measures the gas productions that they eructate. And it also measures oxygen consumption of the cows. So it's a pasture based system, it's on solar panels, so we can take it out to the pastures, and then that way we're not disrupting the normal grazing patterns of the cows. 

Emile: Excellent, thanks. It sounds like a really interesting, novel type of system. Have there been any systems like this in the past? 

Glenn: No, GreenFeed's the first one that's adapted it to larger production on farm type systems. So it's a fairly new technology that they use to capture the gas emissions from the cows. 

Emile: Excellent. And I'm curious in the research that you're doing, are you measuring only methane or do you measure the suite of gasses measured by the GreenFeed system? 

Glenn: Yes, we measure the suite of gasses. We measure CO2, methane, and then we also measure oxygen consumption.

So then that way we can develop equations for the energetics of the cows. So we'll get more than just the gas production. We'll also help to define the nutrient requirements of the cattle as they're out grazing different pastures. 

Emile: Excellent. And so taking a step back and looking at the big picture, why is it important to measure these gas fluxes and enteric methane from cattle?

Glenn: Yes, cattle received a bad rap that we produce too much greenhouse gas and then it's part of the natural ecosystem for cattle to eat, consume the forages, then they do produce CO2 and methane. Which are naturally fermented products, but the CO2 then goes into atmospheric CO2 and then the plants will capture that. And then recycle it through the cattle. So we have had a bad rap though, that cattle produce too much methane or too much greenhouse gasses. 

Emile: Right. So this research then is really putting a fine point on it and measuring those numbers so that you can estimate the actual emissions from cattle and, and with a variety of different types of feed, eventually?

Glenn: Yes, yes. So, what we've got on this current project is we are looking at perennial pastures versus annual pastures. So, the perennial pastures will contain primarily cool season grasses, and then the annuals we're doing cool season grasses there too, but it's just looking at different production scenarios to see if there's a difference in gas production for the cows that are grazing either the perennial pasture or the annual pastures.

Sarah: Thanks, Glenn. So I imagine that there might have been a surge in this type of research as people have become more interested and aware of greenhouse gas emissions. So is this a whole new area of research? 

Glenn: Yes, it's fairly new. There's been a lot of emphasis on just trying to figure out how much of the gasses are actually produced by the animals through their production cycle.

And then one of the advantages that we have is that we can look at production all the way from conception through the feedlot. So we're going to be able to do complete production systems with the technology that we have. But there has been an emphasis on this type of research to help with the, just defining how much gasses the animals actually will produce.

And then sooner or later, there's going to be carbon credits. In fact, there is already carbon credits in some countries, you know, and we're going to be able to help define kind of what the animals or what sustainability practices will contribute for carbon credits for the industry. 

Sarah: Could you explain that just a little bit, what you mean by carbon credits for our listeners?

Glenn: Yeah, so carbon credits are where a lot of companies and a lot of industries want to be carbon neutral. So then there really is no research to define what that means. So we're trying to develop the data so that we can actually be able to define you know, how much does the animals contribute towards, you know, improving the environment?

So, and a lot of the larger companies will actually buy carbon credits from producers, like the big corporations that want to be carbon neutral will buy carbon credits from ranchers and farmers. 

Emile: So let me make sure I understand the picture here, and I think I do. But, for example, if your research finds that emissions are lower on one type of pasture than another, then maybe those emissions could be considered saved or reduced, or maybe if some type of feed results in a lower emissions from, from cattle, then that difference could potentially be purchased by a company that is trying to have net zero greenhouse gas emissions.

Is that kind of a scenario? 

Glenn: That could be, yes, yes. And then so that could help with the production for the producers, pre performance of the animals too, at the same time, so we're looking at the whole picture is what we're trying to do. 

Sarah: Excellent. Thank you. So how, I'm just wondering how expensive is this gas measuring device? Is this something that private livestock managers might be able to use even, you know, outside of the research sphere? 

Glenn: Yes. So they're pretty expensive. The pasture units that we purchased were about $145,000 each, so they would be cost prohibitive for a producer to buy one at this point. You can get stationary units, would be less expensive, but then you have to have your pastures or your farm set up so the animals could utilize that.

And as we develop more data, there may be opportunities for seed stock or producers of animals for reproduction could benefit from this technology if they get some measures for efficiency of the animals or the amount of gas that's produced. Then they could develop EPDs or expected progeny differences for those components on the bulls and the heifers that they sell to other producers, commercial producers.

Sarah: Okay. So does that mean then that most of these GreenFeed systems then are used mostly for research right now, given the cost? 

Glenn: Yes. Yeah. And there's few universities actually have the units. They’re getting more and more abundant, but that's a lot of money to spend on these units. So we were fortunate with the Southwest Beef Sustainability, the project that we’re on that we could purchase these units because we're looking at sustainability of beef production with these units. So, so we were fortunate to have that money to purchase the systems. 

Sarah: Okay, great. Have you run into any challenges when implementing the system? 

Glenn: Environmental challenges is what we ran into last year. We wanted to have the study completed by now, but we have been in a drought, so we didn't get our annual forages to grow last year.

And then the perennials that we planted, they really didn't flourish like I was hoping they were because we didn't receive very much rainfall here in the, uh, Northeastern New Mexico. 

Emile: So probably most of our audience doesn't have a deep background on methane coming from cattle. And so I'm curious about what kinds of things affect how much methane a cow burps out because that's basically what you're measuring.

Glenn: That is correct. So it's related to intake diet. So that's one of the things on the diet that's what we're interested in is will there be differences between a perennial pasture versus annual pastures? And then the fermentation, so methane is a naturally occurring by-product of fermentation. So there's, uh, the higher quality of the diet, the less methane that is produced by the animals.

In fact, in feedlots, it's significantly less methane produced in the feedlot versus when they're grazing. So, so we kind of believe that to make progress in the reduction in methane, probably the most significant impact is going to be while the animals are grazing. 

Emile: So that means that while they're in feedlots, they have a higher quality diet and because of that higher quality diet, there's less methane produced per animal. 

Glenn: Yes. 

Emile: Okay. 

Glenn: And then not only that, they also finish faster. So they're on feed for less amount of time than say we were looking at grass fed animals. So the total amount of methane is going to be lower there too. 

Emile: Because there's less time for, for the production. Great. Okay. So what methane measurement project or projects do you have going on right now? You mentioned a little bit kind of that this is a new system for you and you mentioned the pastures. And do you have others that are going on right now and what are you hoping to learn? 

Glenn: We are currently doing the one with the perennial versus the annuals, but then there's also going to be opportunities working with different feed additives to see how effective they are when the animals are grazing the during the cow calf production or stocker production. We will be just continuing this research to look at the best ways to reduce the amount of methane that's produced by these animals. 

Emile: So you see this as a research program that will be growing into the future to test different scenarios and different, uh, options. 

Glenn: Yes, I'm hoping. This isn't a one-time project, so that's one of the things, the advantages to purchasing these units is that we're going to be able to look at all different types of scenarios, just to see what can be done to improve the gas production, and then we're really going to be able to do the carbon balance on these animals. 

Emile: Excellent. That, and I think you've already really led us to this question, which is, how can this knowledge lead to more broad scale reduction in gas emissions from cattle? And you started to talk about that just a moment ago.

Glenn: Yeah, so we were hoping, well, any information is always good information. Even if there's no significant differences, we're going to be able to, just like a different production practices, one of the advantages to the perennial pastures is you don't have to drive a tractor in the field, so you should get improved soil health, you should get improved water utilization by the pastures, and then just improved performance of the animals.

It's going to be very palatable, the animals are going to love these different pastures. So ultimately what we're hoping to do is provide information to producers on what is the best practice that they can do to make the facility or the production practice more sustainable. And then that should help with the climate change is what our ultimate goal is.

Emile: And it seems like there's an opportunity here for economic sustainability too, potentially. 

Glenn: Yes, so if we can show what is happening and what we can do to improve on the production practices, it should help with the economics of the communities, the rural communities, where we can help them remain viable. Because there's one thing we know is the Ogallala was, what we sit on is declining, and then there's a lot of row crop production, and if we can show producers how they can convert from row crop to more sustainable practices using cattle, that will help in the economic benefits to rural communities.

Emile: Excellent. And, and to build on that, is there differences between animal differences? So is there a possibility of breeding cows that may emit less? 

Glenn: Yes. That's also something we want to work on because it's going to be related to the amount of feed that the animals eat. And one of the things we're also looking on this project, so we can look at the energetics of the animal, which is how we measure their requirements for energy, and then if we can come up with some EPDs for that, then we could have people produce animals that are more efficient in the fermentation processes. So if they're more efficient at fermentation, they should be more efficient at producing the end product or muscle. That’s what we’re looking at.

Sarah: So you mentioned the cost of this and how it might be cost prohibitive for, you know, private ranchers to be using this system. But can you think of other opportunities for using this GreenFeed system beyond how it's currently being used?

Glenn: That's a good question. So yeah, I think so, you know, because if we can just help to develop not only the, just the gas production, we can start developing more equations for the energetics of the animals. So on energetics, that would be breaking everything down from the different forage fractions all the way into the muscle and fat in the body.

So, so being able to work on this previously or kind of the gold standard for energetics is putting the animals in environmental chambers and measuring the gasses there. But if we can measure it, you know, out in the field with production settings, that should make a more real world equations that we can use to apply to livestock nutrition.

Sarah: Okay, great. So is there anything that we didn't ask you today that you wish we had? 

Glenn: One of the things, so we, beside the GreenFeed units, we also purchased a, uh, Gasmet, which is an instrument to measure gas production and then we also have a chamber that we're going to be measuring gas production from the soils, so that we can do the gas production from the soils, we can do gas production from the cows, and then we also have the equipment in our laboratory where we can measure gas production from the forages.

So the only thing we're missing would be environmental gas production, but everything else is really set up so that we can measure total carbon balance with the cows from, let me say, from conception to through the feedlot.

Sarah: That's great. Really looking at the whole picture. Yeah. And not just the cows themselves.

Glenn: Yeah. So it's really exciting research, you know, to be able to do this. 

Sarah: Yeah. I'm excited to see what the results are. Actually, speaking of that, um, when do you anticipate, you know, having some results from this research? Are we talking a couple years? 

Glenn: No, uh, we have a graduate student, she's here right now, that we have the units out in the pastures, and we'll be doing a replicate this, uh, spring, summer, and then we'll be planting another annual crop in the fall.

So we're going to be able to have the results collected in December, and then hopefully she will defend next spring. And we're planning on submitting these publications as she gets them collected, because there won't be any of the laboratory analysis that she'll have to do on the gas production team should be able to do real time collection of data from the gas units.

Sarah: Excellent. Okay. So we like to ask all of the experts that come onto our podcast about what gives them hope for the future. And so I'm going to ask you that question. What gives you hope? 

Glenn: That we are going to be able to help define exactly what the carbon footprint is of cattle, you know, because there's just a lot of bad press. And I don't think we do a very good job of informing the public of the benefits that we have from livestock production, but being able to get the word out. 

Sarah: So if people only remember one thing from our conversation, what is that one thing that you'd like them to remember? 

Glenn: That ruminants are very efficient at harvesting grass that we aren't able to utilize ourselves and converting it into protein. So then if we are environmentally friendly, then there's a really a great opportunity to define these systems and look at better production practices for reducing gas production by the cows. 

Sarah: Okay, great. Emile, is there anything else that you'd like to, to add before we sign off?

Emile: I'd just like to thank Glenn for joining us today, for being a great partner over the last five years or so and working on the Sustainable Southwest Beef Project. It's really exciting to see where it's going and, and when this project started, I don't believe that this was an initial component of the project. This was something that, that was added with in the lifetime of the project. Is that, am I remembering that correctly? 

Glenn: Yes, so that's a spinoff from our project, because one of the things that we were able to do is, since we're looking at sustainability, just to be able to buy these instruments from, from the project really helped to expand the project beyond the life of its term that we have for for funding. And it'll be, there's going to be funding in the future for this type of research. We're excited about that. 

Emile: Absolutely. You're learning some really important things and I look forward to finding more about them, sharing them, and thank you so much for talking with us today. 

Sarah: Thanks, Glenn. 

Glenn: Thank you. It's been a pleasure.

Emile: Thanks for listening to Come Rain or Shine, podcast Southwest Climate Hub 

Sarah: and the USGS Southwest CASC. If you liked this podcast, don't forget to rate or review it and subscribe for more great episodes. A special thanks to our production crew, Skye Aney and Reanna Burnett. If you want more information, have any questions for the speakers, or would like to offer feedback, please reach out to us via our websites.