Minnesota's Swine & U

Sarah Schieck Boelke:
Hello, and welcome to Minnesota's Swine and U podcast series, a University of Minnesota Extension swine program. Today's podcast is a research update on how feeding programs can affect sustainability of pork production. My name is Sarah Schieck Boelke, your host, and I'm a Swine Extension Educator with the University of Minnesota. Joining me today is Edward Yang, who is a PhD candidate in the Department of Animal Science.

To get us started today, Edward, will you tell us a little bit about yourself, including who you have been working with through your PhD program?

Edward Yang:
Thank you, Sarah, for having me. Hello, everyone. My name is Edward, and I am a PhD candidate at the University of Minnesota Department of Animal Science, and I work with Drs. Jerry Shurson and Pedro Urriola. My focus is on swine nutrition, but I also have a minor in business management because I always want to combine science and business together and see how we can help the pork producers.

And I'll be glad to share my research with you today.

Sarah Schieck Boelke:
Great, thank you. And correct me if I'm wrong, but you did your master's work also at the University of Minnesota, is that correct?

Edward Yang: Yes, it is. So I finished my master's in 2018 with the same advisors, Doctor. Jerry Sherson and Pedro Uriola. And actually Sarah and I recorded a podcast on my master program back then.

Sarah Schieck Boelke:
Yes, I remember that. So today, this is your second time around that I've got you to record a podcast with me. And I thank you for your willingness to do that because it's one of the ways that I am able to get the great research that's being done by both our faculty as well as students at the University of Minnesota and sharing that with not only the pork industry in Minnesota, but as well as, you know, podcasts can be heard anywhere. So I'm sure there's producers in other states as well that listen. So thank you for sharing.

So what research topic will you be sharing with us today?

Edward Yang:
So as Sarah, as you mentioned earlier, today I will be talking about how feeding programs can change sustainability of pork production. And this is actually a very broad concept because sustainability and climate change, no doubt, are the topics that the consumers talk and discuss and care about these days. And with animal agriculture being attacked by many groups, this is our chance to tell them our story.

Sarah Schieck Boelke:
Thank you. Like you mentioned, yes, sustainability is top of mind, not only in the pork industry these days, but other industries as well. And as you probably are aware of, National Pork Board, as well as the industry as a whole, has their on farm sustainability reports as an initiative for producers to get a better idea of their sustainability efforts on farms. But we'll talk about your research today. And before we get too far, of course, cannot be completed unless we've got a funding source, and it's always good to give a shout out and a thank you to that funding source.

So are you able to share how is this research being funded?

Edward Yang:
Yep, so this research is actually funded by the United Soybean Board. And fortunately, several students like me and our advisors helped us in the whole process of writing this grant. And it's really a good practice for the students because we started the draft, but of course the advisors should take most credit, but it's a great, great practice.

Sarah Schieck Boelke:
Yes, it is. Because like you mentioned, you're a PhD candidate. So after this, either you might be looking for a faculty position continuing in industry in a research role, you'll most likely be applying for funding grants there as well. So can you give a brief introduction about your research explaining why it was a valuable project to do?

Edward Yang:
Yep, of course. So let's start with some data. According to the FAO, food animal agriculture contribute to about 14.5% of the total human induced greenhouse gas emission every year. Of course, dairy and beef are the two largest contributors, but poultry and swine each contribute about 9% of that, which is not a lot, but still considerable. But about 50% of the total greenhouse gas from animal production came from feed, either feed production, processing, or transportation.

So if there's a way we can select feed ingredients that have less environmental impact, it can bring huge opportunities to reduce the total emission of animal agriculture. And secondly, pig, even though very efficient animal of producing protein, it's not very efficient in converting protein in the feed into protein in the pork, because several studies have shown that pigs can only retain about 30 to 45% of the total nitrogen they consume, and the rest 55 to 75% will be wasted. Even though we have proper manure management processes, we might be able to help recycle some nitrogen, still a significant portion will be emitted and be converted into a compound called nitrous oxide N2O. And it is a very natural greenhouse gas because if you think about methane, cattle industry got criticized a lot for the methane emission, but methane is only 28 times worse than carbon dioxide and nitrous oxide from the pig manure is actually two sixty five times worse than carbon dioxide, making it much, much worse than methane as a greenhouse gas. So now we know the problem.

We as nutritionists wonder if ingredient selection or diet formulation can make a difference in the environmental impact of pork industry. But if we can't measure it, we can't improve it. And we can't even tell the consumers exactly quantified numbers. So to win their trust or help us, help our industry improve, we need to find a way to quantify those changes. And life cycle assessment is a holistic accounting method that can quantify environmental impact and guide decision making.

And that's the new approach we are taking into our research. And back to the very beginning, sustainability. Everybody defines that concept differently, but to me, sustainability is a balance among the planet, the people, the pig, and the profit. So we can't sacrifice too much because pork producers also need to survive, right? So in this term, we have to combine the profitability of pork production, efficiency of pork production, and also environmental impact together in a systems thinking way.

And then we can guide our stakeholders' decision making. And that's how we want this research to start. And back to the actual research, what diet formulation can we change? So in fact, soybean meal has been the golden standard in swine diets for many, many decades, but some people have started criticizing soybean meal being not sustainable. And then we have many ways to replace soybean meal in the diet.

For example, low protein diets where we can use synthetic amino acids to reduce the soybean use and reduce crude protein content and reduce nitrogen emission. But there are problems with low protein diets. The diets may not be as efficient or the pigs might not perform the same. So we have to keep that in mind. And another strategy to replace soybean meal is the use of distiller screens, DDGS.

And in recent years, we have found that with the use of DDGS, actually there is a problem with the branched chain amino acids. There are three amino acids, leucine, isoleucine, valine. The shared catabolism pathways and DDGS have very high leucine which will impact the feed intake and gain of the pigs. So research around different university in The US have started looking at can we counter effect? Can we add synthetic amino acids also to improve that nitrogen efficiency?

So in this research, we combine all these different feeding programs together. We want to look at if they affect growth performance, if it affects nutrient utilization, and most importantly, does it affect environmental impact? And then we combine all this together to guide our decision making.

Sarah Schieck Boelke:
Very interesting. And thank you for that background. So now can you share, how did you complete this study?

Edward Yang:
Yep, of course. So this is not an easy project because we actually split it into three parts. The first part is a traditional growth performance and carcass study were we did in Morris, Minnesota at the West Central Research and Outreach Center of University of Minnesota. We had a group of pigs last in 2021 in the summer, and we conducted a four phase growing grow finish trial. And those pigs were fed four diets I mentioned: a corn soy diet, a low protein diet, a DDGS diet, and a DDGS diet supplemented with synthetic isoleucine, valine, and tryptophan to counter effect that branched chain amino acid imbalance.

And then we harvest those pigs to look at the carcass because the growth in the carcass will impact how pork producers can get their paycheck back, right? So that's the first portion of that study. The second portion we did in Waseca, Minnesota at Southern Research Outreach Center of the University of Minnesota in the Metabolism Unit, where we house the pigs in metabolism crates and measure their nitrogen and phosphorus balance and look at how efficient these animals, the grower pigs especially, can utilize these nutrients and how much they will excrete. And once we have that information, we combine the results from the first two, the actual growth performance and the actual nutrient utilization, into a life cycle assessment model. And this will help us calculate the environmental impacts of different diets and specific diets, because we keep everything else the same.

And by doing this, we can generate information on economically important data like growth performance and carcass. We can get nutrient utilization efficiencies and also environmental impact parameters.

Sarah Schieck Boelke:
It sounds like you were quite busy with all these different projects.

Edward Yang:
Yes, so last year for me it's quite busy and we have labor shortage, we have all the supply chain disruptions, and people may remember climate change actually impacted our industry because last summer we had several heat waves and droughts and everything, and the pigs suffered and the crops suffered and everything else. So it's quite a year.

Sarah Schieck Boelke:
Yes, but you obviously were able to complete those studies because otherwise you wouldn't be talking to me today about what results you have. So please share with us the results of your studies.

Edward Yang:
Yep, and I will walk you through each study, the three portions. So the first one is the growth performance. We grow those peaks from 35 kilograms or about 60 pounds all the way to market weight at 125 or 260 pounds. And because of the heat stress during last summer, those pigs might grow a little bit slower, but all pigs were impacted the same way. So look at the growth performance data, the pigs fed corn soybean meal diet actually have the highest final body weight as we expected.

And the pigs fed the DDGS diet actually had the lowest numerical final body weight, but there was no difference in every daily gain and every daily feed intake. The only difference we observed was gain to feed ratio, the efficiency. So that is the growth performance. And then we harvest those pigs to look at the carcass, and we did not observe differences among carcass weight, yield percentage, fat free lean. So this is telling us with this first study, we can formulate diets to achieve similar growth performance and carcass characteristics.

And so even when we change diets, we don't have to sacrifice performance or your paycheck. And the second study, we look at the nitrogen and phosphorus utilization. Actually, this information agree with what other studies have found that low protein diets actually have the highest nitrogen utilization rate because the diets have less nitrogen, the pigs will try to use it more efficiently. And the diet with corn soybean meal diets have the highest nitrogen retention per day, but because the pigs were eating more nitrogen out of the diet, they also excreted more. And for phosphorus, we did not observe much differences in excretion because phytase was added in all diets, so they were impacted the same way.

And also take blood from those pigs after the trial, and we look at blood urea nitrogen, which is a good indicator of how poor or good that diet protein quality. And the pigs fed low protein diet had the lowest body of blood urea nitrogen, which means they utilize the nitrogen pretty efficiently. So with data from the second study, we know we can formulate diets to achieve similar growth performance, but change efficiency or improve nitrogen efficiency. And then we combine all this actual primary data, first hand data into the life cycle assessment calculation model. And we specifically did Minnesota, like how the ingredients were transported from the local area to our feed mill and to our pig barn in Minnesota.

We can only do at state level. We can't go to county or even smaller geographical area because that's the limitation of the model, but it's good enough for now, right? And then the model will calculate the output in the mathematical model, which is beyond my knowledge. But when we look at the results, we look at several important parameters. First is that climate change impact, and this is something everybody talks about these days, carbon and climate change.

And to manufacture the feed, we need to burn fossil fuel, which impact that climate change. And many other processes along the supply chain will also produce greenhouse gas that change climate change. And by combining all those things together, we get one number, which is a kilogram of carbon dioxide equivalent. And you might hear that number very, very often in the future from all different kinds of labels. But in this study specifically, we use that corn soybean meal diet as a reference and compare with the other three feeding programs.

And to our surprise, the corn soybean meal diet actually had the least impact on climate change. And that is because when we look at a low protein diet or DDGS diet, the production of the synthetic amino acid or the production of distillers all are run by machineries or factories or plants that run on fossil fuel or non renewable energies and emit greenhouse gas. So that is not too surprising, but the bottom line is corn soybean meal diet actually have the lowest impact on climate change. But also there are other parameters we look at, for example, acidification. When the carbon is not going to the atmosphere to form those greenhouse gasses, it might combine with liquids and other forms of materials and cause acid rains, which is a term that most people are familiar with.

And that's also an environmental concern. If the environment is too acidic and the nature doesn't have the ability to neutralize it, then we will see problems. And with our data, we saw that low protein diet actually had the lowest impact on acidification. And then the next one we look at is water use. And this is quite important because last year people may remember we had droughts and the water use were limited, right?

So this is quite important when we talk about the environment. And the water use measurement is quite straightforward, the amount of water use that's required in all different processes. And because ethanol plants actually need a lot of water to ferment that corn into ethanol, they require water. So all these diets with DDGS actually have an increase in water use, while the corn soy diet and the low protein diets are okay. They have a lower water use impacts.

And also we looked at fossil resource use, which means non renewable energy. And similar to the previous one, because the production of distillers were run by plants that require a lot of energy, the diets with distillers have higher fossil resource use, while corn soybean meal diet and low protein diet does not have that high impact on fossil resource use. So the last one we will be talking about is land use, and land use is oftentimes associated with deforestation because there is a competition for land between agriculture and the many other industries and our own humans.

But this is not a common issue in The United States, but in the Amazon Rainforest. However, as a crop, requires the most land use in most cases, and all diets that replace soybean meal can achieve various degrees of reduction on the land use requirement. So the corn soybean meal diet actually have the highest impact on land use, while the DDGS diet where we replaced a significant amount of soybean meal have less requirement on land use. And if we go to countries like Brazil, then there will be a totally different story, or Europe, because they import a lot of soybean meal from Brazil. So that's the three different studies, and in conclusion, we want to say that we can formulate environmentally friendly diets that we can improve nitrogen efficiency without compromising productivity.

And also a new tool we used in this study, it's life cycle assessment, and you might be hearing this more and more often. But climate change, carbon footprint, we talk about all the time. And for pork producers, large pork production, if your goal is to lower carbon footprint, in this study maybe we suggest that corn soybean meal is the feeding program that we should use, but in other places or other companies land use or water use was more limited, then you may have to choose a different strategy. So with the information we generated from this study, people can make different decisions based on what they really want. And another future direction in Europe, actually many institutes have started the formulation programs called multi objective formulation, where environmental impact is actually a parameters that they can put in their diet formulation.

So when they look at diet formulation, they not only look at the price, availability, or nutrient level, they also look at how environmentally friendly it is. And that might be a future direction for us in The United States. And to just summarize exactly what we discussed as a whole, I just want to tell people that all the sustainability stuff that we're talking about is not a number game. For example, Sarah, you mentioned the National Pork Board have the We Care Program, then we have the sustainability report, and several Minnesota large pork producers publish their annual sustainability reports. And they're not just playing with numbers. We're trying to find ways that we can actually implant improvements.

Sarah Schieck Boelke:
Thank you. Lots of information that you gleaned from the different projects that made up your larger research project. So I know you already gave some of the conclusions. So is there any other conclusions that can be made from your study that maybe you have not talked about yet?

Edward Yang:
Yep, yep. So, well, when I was discussing the results of my studies, I'm focused more on exactly what information extracted from the research, but from a broader sense at the University of Minnesota, we focus a lot on sustainability of pork production. And that's the reason why I want to also bring a take home message for all our producers that sustainability in pork production should be done in many ways that we adopt different things like renewable energy, feeding programs, manure management. But as nutritionists, we believe that feed or diet formulation can make an impact. And within our peak world, many initiatives are emerging because key players are taking actions towards more sustainable systems.

Like I just mentioned, National Pork Board, large pork producers, feed companies, companies in allied industries, they're all publishing annual sustainability reports. Not only to show the progress we have made, but also earn the trust from our customers, because at the end of the day, someone has to pay for it. And if our consumers know what we're doing, they may be willing to be that part. And as an industry, there are a lot of things we can do and we need to do. But right now people might be skeptical about things we're doing, but from my perspective, we are on the right direction.

Are doing the right things, but it might take some time to get things implemented and have people really understand the information and the bigger impact we can make.

Sarah Schieck Boelke:
Great, thank you. So why are these results that you shared important takeaways?

Edward Yang:
Why are they important? First of all, feed. As again, we showed that feed alone might be able to guide our decision making and help pork industries be more sustainable. And the second, we showed that these are not easy decisions because when you look at growth performance, which is linked to your profitability of a pig farm, and nutrient efficiency, which is mainly about how we can utilize resources and also environmental impact. One diet might not be able to solve all problems, but with the information we have, people can choose a feeding program that feeds their own need.

And to my knowledge, those information are not available in a broader way or sense. So we are probably one of the first groups to actually combine those things together and be like, hey, now we have all this information, you can pick something that meet your need.

Sarah Schieck Boelke:
So it's been very interesting hearing about your research today, Edward. So I want to thank you for your time and willingness to record with me since you have recorded a podcast with me previously on your master's research. So to wrap up our discussion here today, are there any closing remarks that you would like to make?

Edward Yang:
Well, I wanna end my talk with this statement that there are changes we need to do. And this change can be business opportunities because sustainability, again, is not playing with numbers. It's actual things we are going to change how we do things and influence our next generations. And I would encourage a lot of the pork producers to go out and talk to your, for example, extension educators like Sarah and National Pork Board and Minnesota Pork Board, and really learn about what we are doing in the area of sustainability.

Sarah Schieck Boelke:
Great, thank you. And thank you, Edward, for putting that plug in about sustainability because, yeah, that's one of the things that not only myself, but then also Diane DeWitt, the other Swine Extension educator, yeah, working with National Pork Board and Minnesota Pork on the on farm sustainability reports that the industry currently has as an initiative. So that's good to tie all of that into not only what's going on in the industry now, but then also your research and helping to get the point across on how important your research is to what the industry is currently working on. So thank you. And I want to thank you again for your willingness to record a podcast with me on how feeding programs can affect sustainability of pork production.

And I'd also like to thank those listening to the University of Minnesota Swine and U podcast. This has been Sarah Sheikh Belke, Swine Extension Educator, along with Edward Yang, a PhD candidate in the Department of Animal Science. To further connect with the University of Minnesota Swine Extension, please visit the swine specific web pages on the University of Minnesota Extension's website at www.extension.umn.edu/swine and on those pages you'll find connections to our blog and Facebook page. To learn about research being done by our Swine Faculty in Veterinary Medicine please visit their Swine in Minnesota blog at www.umnswinenews.com.