Bovine Banter

Episode 22.3: Precision Nutrition Research with Dr. Leoni Martins

• Penn State Extension • Season 22 • Episode 3

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Meet new Penn State Extension dairy team member and faculty researcher, Dr. Leoni Martins as he shares about his work in the area of precision nutrition. 

Host: Ginger Fenton, Guest: Leoni Martins

Image credit: Penn State Dairy Team 

Ginger Fenton:

Welcome to Bovine Banter with the Penn State Extension Dairy Team. My name's Ginger Fenton and I'm an educator based in Mercer County, Pennsylvania. I'm excited to welcome Dr. Leoni Martins to our podcast today. Dr. Martens recently joined the faculty and dairy extension team at Penn State as an assistant clinical professor of precision dairy nutrition. Welcome, Dr. Martins. I look forward to learning more about your work in Precision Nutrition today.

Leoni Martins:

Thank you so much. I'm happy to be here. Yeah.

Ginger Fenton:

Can you please introduce yourself and tell us a bit about your interests and what drew you to Extension?

Leoni Martins:

All right. So I grew up in Brazil. My dad has a small dairy farm down there. We milk uh cows in the grazing system. And uh as a dairy kid, I was wondering what I was gonna do of my life. Uh and I decided to go to vet school. So uh went to vet school. I wasn't very sure about which pathway I would follow. I knew I wanted to work with cows, but I didn't had a grasp at that moment on whether it would be nutrition, reproduction, or whatever. And I spent a couple of years in a veterinary hospital doing some internship with them, and and I didn't like the the clinics aspect of being a cow vet. Uh and in the meantime, I was doing some work with a professor uh that his specialty was nutrition. Uh so we we interacted a lot during that time, and I had the opportunity to be exposed to research and and in nutrition. Uh, and that really uh sparked a love uh for research and also uh being a nutritionist became some sort of of goal uh for my my career. And then I decided to pursue a master's after that. So I did a master's uh in nutrition, uh working with forage quality and and uh calves and and all sorts of works related to nutrition in young animals and also lactating cows. Uh and at that time I decided I wanted to stay in academia because research was really a passion of mine, and uh I decided to pursue a PhD. That's when I came to the United States back in 2019. I spent almost two years at Purdue University uh working with transition cows, uh, calcium metabolism, inflammation, uh more of a physiological studies uh around the pre-parton period. Uh, and then I had the opportunity to come to Penn State to pursue my PhD, uh, which was related to precision nutrition and nutritional strategies in general to uh mitigate uh enteric methane emissions and to optimize nutrient use efficiency. And that's pretty much my background. And back in Brazil, uh, while doing my master's, I was also working as a consultant in some farms, and that really made me think that whatever career path I would follow, I would have to be able to translate my research into practical applications. And, you know, in the future, if I I was to be uh a faculty in some institution, I would like to have some extension appointment. So that that's pretty much what drove me to uh be an extension professor here at Penn State.

Ginger Fenton:

Sure, I can appreciate that. I think that's also what drew me to extension is being able to translate the science into that practical application. Can you tell us how your dairy background has prepared you for your role with precision nutrition? Because that's in your title.

Leoni Martins:

Yeah. Uh so yeah, my title is uh assistant clinical professor of precision dairy nutrition. And precision nutrition can be quite a broad term. Um I think we're still trying to find a good definition for for that precision word. Uh, but the way I say this is that precision uh is related to collecting data, collecting information, or collecting data to generate information and using that information to uh make decisions. All right. So every time that we are making uh sound decisions based on data that we collect on farms, uh I would I would consider that being as precision, precision dairy farming. Most people will consider uh precision or the first thing that comes to mind when we're talking about precision farming is probably sensors, technologies, robots, uh, all those cool stuff that we see nowadays on farms. But the reality is that those are just tools uh for a much bigger concept and a much older concept, uh, which is precision nutrition. So, way back in time when we were trying to figure out how to make cows produce more milk or how to balance better diets, uh, we were already doing precision nutrition. So, again, looking into the farm, looking into the real life, trying to collect some data, interpret that data, and take some or make some decisions based on that specific situation. So uh how my background uh helped me or still helped helps me in this role, I think that is having the experience of being a consultant in dairy farms back in Brazil, growing in a dairy farm, and understanding that uh, you know, a farm is not just nutrition, a farm is not just reproduction uh or health, it's it's the combination of all those fields help me to think more holistically about my role as a precision nutrition professor. So back in Brazil, we used to have uh opinions and and help the farmer decide, even on the financial level, uh, because most of these precision nutrition strategies that are gonna implement, the goal most of the times will be increased profitability. So the way I see this is a general view of the farm as a system and how nutrition is interacted with all other fields uh in in the dairy. So pretty much having this background uh helped me to uh develop uh a precision nutrition program and approach that is farm dependent and based on the goal of each farm and the challenges that each farm may face.

Ginger Fenton:

Yeah, I think that's that's a great way to lead into my next question, which is what type of extension programs encompass precision nutrition? I know you've already been out working with some of our educators and doing some programs. So could you tell us a little bit about some programs, please?

Leoni Martins:

Yes, absolutely. So as a broad term, and as I mentioned that it will probably be farm dependent, all programs that we try to develop looking into how to improve forage quality, for example, uh, how to improve feed and feeding management, these will all be encompassed by this precision nutrition program, right? Uh so harvesting management, insiling management, how well we are taking care of our uh our bunkers, our corn salad, our uh alfalfa, small grains, and so on, uh, these all can be uh incorporated into a precision nutrition program. More specifically here at Penn State, uh, we've been developing some feeding assessments, which we visit farms, uh, usually collaborating with nutritionists, veterinarians, and all the farm team that is already involved doing their job there. Uh, but maybe they have some challenges that they need some outside person to kind of come with fresh eyes and try to identify issues that they may not be seen because they are dealing with those uh those issues on a daily basis. And you know, they they are not as clear for for somebody that is immersed in in this uh farm. And then we come, we visit the farm, we make a complete feed and feeding assessment. And what that means is that we collect porridge samples, we collect all feed samples for analysis, we try to measure or to quantify variability in in the TMR mixing if the farm is feeding a total mixed ration. Uh, we try to find uh opportunities in during the feeding processing. For example, are there opportunities to change the loading sequency of feeds and have a better mixture of the diet? Are there opportunities to better distribute the feed for the cows? Can we maybe change some uh group of cows that will probably help in terms of competition and hierarchy? Can we look into why the cows are probably milk fat depressed and they are not responding as you would expect? Is that related to some sort of particle size of the diet, to some sort of grain processing? Uh so we visit the farm and we try to have uh uh a third-party assessment uh that will help nutritionists, veterinarians, and the farmer to troubleshoot whatever issues they may have. And uh sometimes we we are called into the farms not because they think it's a nutrition issue, but maybe they think they have a reproduction issue. And you know, we we come to the farm with the person saying our conception rates are low, so can you make sure that there's nothing in nutrition that we could uh be doing differently to improve conception rates? And then we come to the farmer and we try to investigate that. So this is a strong program that we are developing here at Penn State and that we hope to continue moving forward. And other than that, helping farmers to better understand corn salage quality, small grains, alternative forages, these are growing topics that we we've seen in the United States, and how to better harvest those materials and optimize the use of nutrients that they offer, or how to better formulate diets with these alternative feeds that most of the times we don't have a whole bunch of information on them. So this is all part of a precision nutrition program. We also have the same kind of approach for uh component fat herds. We'll probably discuss a little bit more about this later, but my entire PhD was looking into ways to more efficiently feed concentrates separately from the forages to individual cows, which could be a feeding system adopted by high-tech herds, for example, with milking robots and cows coming into the parlor and/or the milking robot and receiving concentrates on an individual animal basis, but also a Thai style herd, which the farmer feeds concentrates separately from the forage and component feeding system. So we do have different approaches based on the type of system that the farm uh has to offer, and we work with the farmer to actually optimize the the use of nutrients and the deliver of nutrients to the cows based on on the farmer's situation and and system. So these are some of the programs that we develop at uh at extension in terms of precision nutrition.

Ginger Fenton:

Yeah, well, we are definitely glad to have you here as a great resource, and I appreciate your willingness to do those programs and to visit farms. I think that's great practical information that farmers can use. You touched on your graduate work at Penn State. You know, you looked at methane emissions and other factors relating to feeding strategies and additives. Can you tell us a little bit more about your work and what the primary findings were of your graduate work?

Leoni Martins:

Yeah, absolutely. So uh my PhD advisor, uh Dr. Alex Ristov, he is a reference in in terms of environmental impact of dairy production. So he started his work mostly with nitrogen, looking into ways to minimize nitrogen uh volatilization in manure. And that's pretty much related to the protein nutrition of cows. And more recently, he he shifted gears a little bit towards enteric methane emissions. So when I came to his lab, I was really skeptical about all this uh methane talk, which has been a you know a hot topic for at least 10 years now, I would say. And I told him, I don't think I really want to work with methane, but I had no choice. I had to work with methane because he was the methane guy. So I'm I'm lucky enough that my my PhD topic was related to precision nutrition, looking into methane, of course, but also going beyond methane, right? But as I was uh in his lab and the opportunities were coming, I had a whole bunch of opportunities to do different experiments looking specifically into methane, right? And just to give some background to our audience on why methane is important, and although it's been on the news a lot on the news in the past 10 years, it's probably at least 67 years that we recognize methane as an energy uh loss during the fermentation of feeds in the rumen, right? So back in the 1950s, we already knew that uh rumen bacteria would uh generate some methane during fermentation, and that methane is a loss of energy that could be used for production purpose or maintenance purpose by the cow, right? So when we are tackling methane, not only from an environmental perspective, but we are also trying to improve the efficiency of energy utilization in the cow. We we were looking into making the cow more efficient in digesting the feed, right? And the losses of energy through methane production in the rumen can be up to 12%. So it can be quite a significant amount of energy that is lost, right? Uh so we've learned a lot in the past 60 years, I would say, in terms of which strategies we could use to try to reduce enteric methane emissions. But the reality is that if we completely shut methane production down, uh the cow will be hurt as well, right? So every time that we have a huge decrease in methane production, probably that is related to decreased dry matter intake that will be related to decreased milk production and probably repro repro-wise and and health-wise, the cow will not be doing well. Uh so we learned that we can reduce methane to some extent, but we're still trying to figure out how far we can go without hurting the cow. Uh, but overall, when most researchers are looking into methane, they are looking into trying to minimize the output of methane relative to the output of milk, because we don't want to make the cows produce less milk just to make them produce less methane. It makes no sense. So part of my work was looking into some feed additives and nutritional strategies that we could uh potentially modify ruminal fermentation and decrease enteric methane emissions. Most of the uh strategies that I looked into were related to feeding natural compounds, like botanical compounds. These are essential oils or phytonutrients that are extracted from plants. For example, capsicum is an essential oil extracted from pepper, clove oil, some of these natural compounds that we fed to cows in very small amounts, and we were able to modify their ruminal fermentation to make them more efficient. And what we learned uh with these studies that pretty much feeding these compounds, we can affect uh enteric methane emission. We can reduce it by 5 to 10 percent on an yield basis that is relative to the intake of the cow, but also on an intensity basis, which is relative to the milk production of the cows. But beyond enteric fermentation and methane production, some of these compounds have a direct effect on the cow physiology. Uh, so some of these compounds will not act just on the rumen, but will also change the way that cows use glucose for milk production or body weight gain, change the way that their immune system will respond to some sort of uh threats. So these compounds kind of open the door for further research on all right, we know that the rumen fermentation aspect is one thing. We're gonna look into this research, but also there are other things that the cow will be gaining uh when we feed uh these compounds. So there are a series of compounds out there, some of them are being heavily used in farms as feed additives. I would say that what we expect from a methane production perspective will be a reduction going from 5 to 10 percent. Now, there are other compounds that we studied that these are a little bit more aggressive in terms of methane reduction. Uh, so most of those are chemical inhibitors, so they are synthetic compounds uh that we would feed to the cows and see reductions of up to 30%. A recent example that was in the news is was the three nitrooxypropanol, uh, which the commercial name is bovar. The FDA has not actually approved this compound to be used in the United States, but it it acknowledged that may not it may not be harmful to the cows, therefore the producers could start using those. So, in theory, nowadays you could feed these uh three nitrooxypropanol to dairy cows, expecting a reduction in methane by up to 30%. But other than these compounds, we have a very hot topic nowadays, which is feeding seaweed to cows. This is a research that is still in the very early stages. Uh, we know that there are some of these seaweeds that are very potent inhibitors. They can decrease methane by up to 90%. But just as I mentioned before, when you reduce that amount of methane, probably you are hurting the cow. And actually, what we see in some of these trials with such a big reduction is that the cows actually crash their dry matter intake and milk production. So this is some of the things that we looked into during my PhD, and we contributed a little bit for the body of knowledge that is yet to come on these compounds.

Ginger Fenton:

Yeah, that's very interesting. And it sounds like it also generated many more research questions, which I think is exciting too. Yeah. So one of the other things that I know you are interested in and working on is research related to feeding soybeans in Pennsylvania. Can you tell us a little bit about this project, please?

Leoni Martins:

Yes. Again, this is another hot topic with the High Lake soybeans. And you could ask why at Precision their nutrition guy is interested in soybeans. And the answer is that this is completely related to precision nutrition, because the way that we process our feeds will have a direct impact on how the cow uses the nutrient. So if we better understand how we process feeds and how to deliver the nutrients to the cows, we can uh actually implement precision nutrition, right? And the idea behind this project came a year ago when I was looking at the literature of soybean processing, and pretty much all the literature available supporting roasting temperatures and particle size of soybeans date back from early 90s. All right. And it's not a whole bunch of studies. Uh, of course, there are quite a few, but you know, uh, when you look at them, uh you gain some knowledge reading those papers, and that sustained our uh industry until this date. But soybeans nowadays are being fed in such great amounts that are very different from the amounts that we were feeding back in 1990, all right, uh, especially with the Hyo Lake. So I was looking at that literature and I was wondering first, uh, with the new soybeans we have, these Hyo Lake soybeans, should the processing methods be different? And second, the the cow of 2025 is very different from the cow from 1990s. Uh, we are seeing this with high milk fats, for example, which it's a complete, completely different cow from five years ago, actually, when they were averaging milk fat at 3.8. Now they are averaging at 4.2 uh butterfat, which is quite impressive. So the cow has changed, soybeans has changed, and we are feeding different amounts in the diets. Uh, I've I've seen nutritionists incorporating up to 16, 20% of these high-alake soybeans in the diet, which is unbelievable uh when you consider feeding that amount of conventional soybeans. So I was thinking about experiments that we could do, but I wanted to have a grasp of what the producers are feeding in the farm, right? Before actually designing an experiment, uh, I wanted to know what is being fed out there, what are the common practices that this the producers are adopting when processing soybeans? So I would like to characterize how soybeans are being processed and used in their farms across Pennsylvania, and hopefully that will kind of represent other states as well, right? And uh I hypothesize back a year ago that I would see uh some variability, and I we are kind of halfway on this project, and I'm quite surprised to see that the variability was way bigger than I expected. And you know, which which tells me that we are going in the right direction on characterizing this and try to understand what's the optimum processing method for soybeans, because if we find what's the optimum, then we we have better guidelines for nutritionists and producers to actually make the the best use of of their feed, right? So that's pretty much what we've been doing uh with with the visiting farms across Pennsylvania, collecting soybean samples, but not just looking into soybeans, we are trying to look at the whole farm. So we are making a complete feeding assessment. We collect TMR samples, we collect horrid samples to see forage quality, we collect milk samples uh to see milk components, milk fatty acids, we collect earring samples and feces to see how much nitrogen these cows are excreting. So I hope to have a good idea and potentially uh be able to correlate the use and the processing of soybeans with how efficient these farms are and come up with some good guidelines to help nutritionists uh make decisions uh in the field.

Ginger Fenton:

Again, a very, very timely topic with the conversation in the world right now. And yeah, I think you also hit a key point there that you're seeing great diversity across our farms in Pennsylvania. That's certainly one thing I observe with being in the western part of the state versus other parts of the state. So as a scientist, we're always trying to answer questions and make new discoveries. I'm curious if you have encountered anything unexpected or unusual through your research projects.

Leoni Martins:

Yeah, always, all the time. Uh, and that's what excites me about research is you know, the discoveries we make during the research process as a whole uh lead us to have more questions. And every time that I finish a research project, I learn that I don't know anything about cows. And uh, you know, that that motivates me to keep going, to continue the work. And some of the things that I've been thinking a lot lately, since my PhD, working with this idea of feeding cows individually, feeding concentrates separately from the forages to individual cows, this idea of cow resilience. I think this is a terminology that we've been we were not using uh until probably two or three years ago, and now we we start seeing this terminology out there. First is uh how resilient these cows are to short-term variation. So it takes a huge effort to screw a cow up. You know, it's not easy to screw a cow up, uh, believe it or not. But we've seen this uh more and more that you know some variation in in diet and some variation in nutrient delivery on a daily basis seem not to affect the cows uh in the short term. We still don't know in the long or or the mid or long terms, but you know, in the short term, they seem to be very resilient to changes, which kind of makes sense because farms are not perfect. The process of processes that we have in farms are not perfect, so there is some variation on a day-to-day basis. And the cows, uh, when they are well managed, they they kind of stay still in their production, right? Uh so cow resilience is something that I've been thinking a lot lately, and with cow resilience, also the between cow variation. So I it amazes me when we were doing this uh individualized concentrate feeding trials, which each cow would get their own amount of nutrients based on the so-called requirements that we had for them, but their responses could be completely different, completely different. So, some cows that the nutritional program would tell me these cows needs 20 pounds of concentrates, and then I would give them 20 pounds of concentrates, but out of the sun they would stop producing milk and they would just gain body weight. Other cows, the nutritional program would tell me this cow needs 15 pounds of concentrate, and then we would give that cow 15, then she would increase two or three pounds in milk response. We would give her a little bit more concentrate, she would keep increasing milk production. And these are cows within the same herd with very similar genetics. So the between cow variation and the individual responses of cows to the treatments that we are applying to them is something that you know uh it was kind of surprising to see uh in all my trials. Uh, we did over three trials uh using this individualized concept, and and you know, I could see those individuals in all of them. So that's something that really uh puzzles me and keep me. Thinking on do we know the requirements of the cows? I don't think we know the requirements. I think we can keep pushing them. Some will keep responding, some will just shut down. And we now need to understand what's the difference between those cows and how we identify them in the herds and you know, uh manage them as they wanted to be managed. So and the other thing that amazes me about cows, and I figured it during my research is how cows can learn habits, usually bad habits. Uh so in our research settings, we try to individualize the the feeding of the cows so we can measure individual dry matter intake. And we use a system that is called uh Kalen gate. So each cow has her own gate. Uh, she has a collar, she comes into the gate, the gate opens, and she puts her head down and starts eating. Uh, and you will see dominant cows learning how to bite on the neck of the cow. So she back up from her gate, and immediately she can sneak in and put her head in before the gate shuts shuts off, you know, and then she could could still feed from from her ears. So these kind of things are are always amazing me when I'm working with cows on research.

Ginger Fenton:

So watch out for the sneaky cows. Got it. For the dairy producers that are listening, I'm sure they're curious about how your research could affect their bottom line financially. What are some of your key nutrition management practices that you want to share with producers?

Leoni Martins:

I think that each each farm will have uh specific challenges and opportunities. Uh, and these challenges and opportunities will uh determine which are the goals of the farm. All right. So I don't really have a set of lists or a list of practices that the farm could adopt from a nutrition perspective because the goals would be completely different from farm to farm. All right. But the common factor among all farms is that nutrition represents one of the highest costs, operating costs in the farm, right? 50 to 7% is the number that we we've always used, and that number is still true, and I think it it will remain true for as long as we milk cows, all right. Uh but some things that uh would always be a common factor for the most profitable farms and the most efficient farms is probably forage quality. Uh, these are farms that are really concerned about the quality of their forages, uh, fiber digestibility, starch digestibility. Uh, they are trying to extract the most out of their forages. These are farms that try to be as consistent as possible, although we just said that maybe short-term variation will not really impact cows. But the reality is that if we try to do everything perfectly on the farm, we're going to still have some variation. So we better control what we can because too much variation may be detrimental to performance, right? So uh I would say having a team that is is compromised uh with the farm, a team that understands the importance of the work they're doing, and you know, working on forage quality, working on having well-mixed diets available to the cows uh at least 22 hours a day. I think this is probably the nutrition-related aspects uh uh that the successful farms would would share.

Ginger Fenton:

Okay. Thank you. So can you tell us what you enjoy most about being a researcher? Like why do you do what you do?

Leoni Martins:

Yeah, that's a good question. Uh I mean, growing uh in a dairy farm back in the day, uh, we were involved in the operation, but didn't really think about the challenges that my dad had. That started striking me most after I went to vet school and he started being a consultant for other farms and said, well, you know, these farmers are having questions and challenges on a daily basis that, you know, they need some help. It's far from me to think that I'm gonna help the world to change, but if I can at least have some impact on clients that I interact with or on the farms that I visit or with the students that I mentor, probably we can we can help 1% of the dairy industry and keep it moving forward. So the challenges that the farmers face in the dairy industry is something that motivates me and and makes me think about uh research and you know what kind of questions do we need to answer to better serve uh the community. And then you will start the research process. You did develop a or design an experiment, you conduct the experiment, you look at the data, start trying to interpret that data. And again, we end up with more questions than than before. So this process of learning about the cows, and every single experiment, by the end of the experiment, I look back and I say, I'm learning that I don't know about cows and I want to know more about them. This kind of motivates me to uh you know continue my job. And and that was kind of the goal since back my masters when I was really involved with research is that I want to be in academia, I want to be a researcher because I want to know more about cows. And the third point that I have for this is it doesn't matter if I know it by myself or just to myself. Uh, I need to be able to share this with those that I interact with. So uh the fact that we interact with students, we train students to serve the industry, we interact with farmers and extension, with nutritionists, with stakeholders, that's kind of the driver to continue doing my job. And that's what motivates me every single day.

Ginger Fenton:

Yeah, I think you're in the right place and in the right career. That's good. Do you have any final thoughts that you want to share with our listeners?

Leoni Martins:

Yeah, sure. Uh so uh as a precision nutrition professor, and going back to the definition of precision nutrition, I think that farms need to measure in order to manage, right? So know your numbers, surround yourself with a team that will is gonna help you, the team is gonna help you to generate information from those numbers. The numbers alone, the data alone will not do anything. And actually, this is one of the frustrations of farmers most of the time is that they are generating tons of money of data and they are don't know what to do with that data. They don't see value on the data that generate, right? So having a team that will help you understand those numbers, create knowledge on those numbers that will help you have better decisions and increase profitability in your farm. And a shameless speech here. Uh, we from Extension, we we are here to support you, your nutritionists, veterinarians, everybody that may uh need some fresh eyes or or some help to troubleshoot and and and discuss things on the farms, we'll be more than happy to collaborate with you and come up with some ideas that may help the farm be more profitable.

Ginger Fenton:

Absolutely. And I'll follow up with that. If any of our listeners want to continue the conversation, please feel free to follow up with me, follow up with Dr. Martins, follow up with anybody on the Penn State Extension Dairy team, and we will be glad to continue, continue the conversation and see how we can be of assistance. Thank you very much, Dr. Martins, for taking the time to talk with us today. Thank you to our listeners. Please don't forget to tune in to our next episode of the Bovine Banter podcast, where our dairy team members will continue to explore topics related to dairy nutrition.