Bovine Banter

Episode 22.2: Highlighting PSU Grad Student Research

• Penn State Extension • Season 22 • Episode 2

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In this episode, Jim Lawhead interviews 2 PSU grad students about their research on the fat nutrition of dairy cows and the economics of cropping strategies.

Jim Lawhead :

Welcome to Bovine Panter, brought to you by the Penn State Dairy Extension Team. I'm Jim Lawhead, Extension Educator based in University Park. Today I'm joined by two special guests, Dr. Alanna Homan, who recently earned her PhD, and Josh Becker, who has just completed his master's degree. They'll be sharing highlights from their research and discussing how their findings can be applied to our dairy farms. Alanna, thanks for joining us. Can you tell us about your background and what brought you to Penn State?

Alanna:

Yeah, thanks for having me. So my background is a little bit of a funny story. So I originally got uh involved working with dairy cows through our county's 4-H program. And that happened because I really wanted a dog growing up. Um, but I am a triplet and I have a younger sister as well. My parents told us there was too many of us kids to have a dog. So they told me to join 4-H instead. And they were expecting me to pick a small animal. We could pick to work with uh a lot of different projects, but as a nine-year-old girl, I said if I couldn't have a dog, I was working with the biggest animal I could. So that's how I got involved working with cows. I fell in love with it. Um I went to Cornell to study animal science as an undergraduate with a focus on dairy, and then I was recommended to come here to Penn State to work with Dr. Kevin Harvateen for grad school.

Jim Lawhead :

Very good. So I guess I guess that tells us a little bit. But how how did you get involved with dairy research and your project in particular?

Alanna:

Yeah, it's a good question. Um I first got involved with dairy research at Cornell, so I worked in a couple of different uh labs, both with calf nutrition and with transition cows. But throughout my studies, I was especially interested in nutrition courses, and just because nutrition can have such a big impact on cow productivity. So it's fascinating to me how quickly you can observe changes uh in milk composition or milk yield when you make dietary changes. So I wanted to focus on nutrition in grad school. And my advisor, Dr. Kevin Harveteen, he went to Cornell for his PhD. So some of my advisors at Cornell knew of him and recommended that I join his lab at Penn State.

Jim Lawhead :

Fantastic. So tell us about your research project and why you were investigating this particular issue.

Alanna:

Yeah, so my main research is funded by the USDA, and it was investigating differences and mammary uptake of fatty acids. So that sounds complicated, but essentially what we were doing is we observed in the field that usually high palmitic acid supplements increase milk fat more than when farmers feed a mix of palmitic and steric acid supplements. And so we wanted to understand what it is about palmitic acid supplementation that's actually increasing milk fat yield. We thought that maybe the udder could have a preference for taking up one kind of fat over the other. So we set up a main experiment with increasing doses or feeding amounts of different types of fat. So we had palmitic acid, we had steric acid, and then we had a no-supplement control group. And then we just fed at different rates. So we fed them at an equivalent of about a third of a pound, two-thirds of a pound, one pound, or 1.5 pounds per day, just to try and understand what those different feeding rates would do on milk fat production and uptake. And then what we also did is we took blood samples, just representing the artery running to the mammary gland, so supply of fat to the mammary gland, and then the vein running from the mammary gland to try and just determine uptake of fat across the udder.

Jim Lawhead :

Fantastic. So, what were your main findings?

Alanna:

So, first we just wanted to look at milk yield and composition. So we didn't see any differences in milk yield between the fat supplements and the no-supplement control. But what we found, as we expected, is that the high palmitic acid supplement increased milk fat yield at lower feeding rates compared to our high Stearic acid supplement. So we started seeing differences in milk fat yield for our palmitic acid supplement at about two-thirds of a pound per cow per day, whereas our Stearic acid supplement, we only saw differences at our highest feeding rate, 1.5 pounds per day. So again, we wanted to kind of understand why this might be the case. So we looked at our blood samples and looked at the difference between the artery sample and the vein sample to try and understand uptake of fat across the mammary gland. And what we found is that when we fed more palmitic acid, the mammary gland took up more palmitic acid into the udder. But when we fed more Stearic acid, there wasn't a change in uptake. So this is showing that the mammary gland might actually have preference for palmitic acid when more is fed, and that uh could be why we're seeing these differences in milk fat response.

Jim Lawhead :

Very interesting. Did you find any impact on milk composition?

Alanna:

Yeah, so uh what we found was that when we fed more palmitic acid supplements, we did increase our palmitic acid content of milk fat. But when we fed more steric acid supplements, we increased Stearic acid and milk fat some, but we also increased oleic acid. So palmitic and Stearic acid, those are both saturated fats, which mean they're solid at room temperature. And then oleic acid is an unsaturated fat. So these differences we saw is due to the fact that the mammary gland has an enzyme that converts Stearic acid into oleic acid. So when we fed more Stearic acid in our supplement, we essentially put more unsaturated fat into milk by having it convert to oleic acid.

Jim Lawhead :

Well, does that impact butter composition?

Alanna:

Yeah, I'm glad you asked. Uh there was some issues of consumers being concerned about their butter in media a couple years ago. The media named it Buttergate, but people were worried that their butter was starting to be hard at room temperature. And they blamed palmitic acid supplementation as the reason for this. And so we were actually running this study, looking to start the study right around that time. So we got uh some funding from the Northeast SAIR to look at that very question: does the supplementation actually impact butter? And so what we did is we used these samples and we created butter oil, so we just spun down the samples to essentially extract the milk fat, and we wanted to look at the percent solid fat across a variety of temperatures. So this would tell us essentially how spreadable the fat is. And so what we saw is that there were mainly differences around room temperature, and so the more palmitic acid we fed in the diet, the more percent solid or the harder the butter was at room temperature. But the opposite was true for our steric acid samples. So the more steric acid we fed to cows, the butter samples were softer at room temperature. They were uh more liquid at room temperature, and that's again due to the increases in oleic acid.

Jim Lawhead :

That's really interesting. Did you look at the economic impact of these diets? Fats are really expensive right now to purchase for feed.

Alanna:

Yeah, that that's a good question. Um, so it's hard to determine an exact economic impact given that the price of fat supplements are constantly changing and the price of butter fat is constantly changing. But the easiest way to start doing that is to look at the transfer efficiency of your fat supplements to milk fat. So essentially what that means is for every pound of fat supplement that you fed, how many pounds of milk fat did you produce extra? And so at the highest feeding rate in our study, we saw that palmitic acid supplements had about a 25% transfer efficiency, and that's kind of considered on the upper end of normal. And so this means that for every pound of palmitic acid that we fed in the diet, you would get a quarter pound of milk fat. And so if you want to look at an economic analysis of that, if you wanted to break even on your supplement just from the cost of or or the value of butter fat price, essentially your butter fat price would need to be four times as high as your fat supplement in order to make up that difference. But as Dr. Harveteen likes to say, that's not necessarily the most fair assessment of fat supplementation because whatever is digested but not used to milk fat that can be used in the body, in the cow for other reasons, whether it's reproduction, whether it's maintenance, whether that's energy for just increasing overall milk yield. So there are other uh benefits to feeding fat besides for just the increase in milk fat. But that that is a way to start uh looking at your economics.

Jim Lawhead :

Well, this ties into the last question, but what what's the take-home message for farmers?

Alanna:

Yeah, so the take-home message is uh you want to look at what the goals on your farm are and where your milk is going or what you want it used for. So if you're a farm that's trying to make your own products, this might be a little bit more pertinent to you. If you're trying to make butter and you're worried about consumer interest in that, you might want to feed a little bit less uh palmitic acid or consider feeding other things such as stric acid or maybe some hyoleic soybeans to try and increase the oleic acid content of your milk to kind of counteract that. If you're making, let's say, ice cream or cheese that's going on pizza, you know, either end of the spectrum, whether it's a product that's really cold or is supposed to be served really warm, these melting properties shouldn't be that different at those more extreme temperatures. If you're looking to just feed for overall milk fat, uh palmitic acid, a supplement high pulmic is a good way to do that, but you also want to just look at your farm to kind of try and understand what other factors could be contributing to help you increase your milk fat, whether that's uh digestible forages or some hyalic soybeans or just looking at the economics to understand is palmitic acid supplement the most efficient way to increase your milk fat.

Jim Lawhead :

Okay, well, how how will your research and education uh guide your future plans?

Alanna:

Yeah, it's a good question. Um so I guess through this all, I just am finding that I really enjoy uh doing uh conducting and explaining applied research, and so I want to consider or continue serving like in that interface between applied research and on-farm application, whether that's through extension or through consulting, you know, now that I have uh just graduated. But I'd also like to just keep following some of these questions up to understand why more why the mammary gland has certain preferences for fatty acids and also what we can do to change properties of milk fat that is beneficial for consumers based on how we feed cows.

Jim Lawhead :

Well, Land, thank you very much for joining us today, and we wish you the best of luck in the future.

Alanna:

Thank you so much for having me.

Jim Lawhead :

And Josh, we appreciate you joining us as well. Uh, can you tell us a little bit about your background and what brought you to Penn State?

Josh:

Yes, so currently I have a dual bachelor's in dairy science and ag business from Virginia Tech. During my time there, I was also able to internship with Virginia Cooperative Extension in Pulaski County, Virginia. My role was to work with producers to help them solve problems and host events to get new research out to them. During my time with Extension, we had a trip to PA with cattle producers in the county because a lot of the Virginia cattle that the producers are growing end up in Pennsylvania. So during that trip, we were able to stop at Penn State's Ag Progress Days. This is where I was able to meet and talk with my current advisor, Dr. Lisa Holden, and she explained the project that I was going to be working on, and it sounded really interesting, so I decided to pursue a master's at Penn State.

Jim Lawhead :

Fantastic. Well, how did you specifically get involved with dairy research?

Josh:

So this actually started very early in my undergrad career. My first research project was to perform more of a lit review on A2 milk, which is a different protein and milk. And this was so I could present at the annual ADSA conference or for the American Dairy Science Association. From there, I wanted to continue researching and presenting, so I talked with Dr. Gonzalo Ferreira at Virginia Tech, who works with dairy nutrition research. With his guidance, I worked on the project to test digestibility of drought stressed corn and dairy cows. While this was interesting, I wanted to be able to tie my background of dairy and economics together, so this is when I decided that working with Dr. Holton would be a great idea.

Jim Lawhead :

Okay. Well, what research project did you get involved with here at Penn State?

Josh:

So my research focuses on evaluating the economic and whole farm sustainability of different manure and weed management strategies in double cropping dairy systems. In simple terms, I wanted to understand how decisions made in the field, like how manure is applied, what herbicide program is used, ripple through the entire dairy farm economics. We compared two approaches. The first is what we call the best management system, which was broadcast manure with standard herbicide. The second was enhanced best management system, which was injected manure with integrated weed management, which uses a reduced herbicide program and mechanical weed control. To analyze this, I used the virtual 65 cow dairy farm model, integrating data from Penn State's dairy cropping systems project, which has been running for over a decade. This project provides detailed yields, nutrients, and crop data. We took those results and we ran them through a financial analysis system called FIMPAC, which is a farm management software that simulates real-world cash flows and profitability. So rather than just looking at what happens in the field, we evaluated how those agronomic decisions would affect a farmer's bottom line over time. Well, what was the reasoning behind your research? This project really came from a conversation with farmers and advisors. Many dairy producers want to adopt practices that are more environmentally sustainable, like reducing nutrient loss, relying less on chemical herbicides, but they need to know if those changes make economic sense. There's a lot of great agronomic research showing manure injection can reduce nitrogen loss and improve nutrient availability, or that integrated weed management can maintain crop yields while using fewer chemicals, but what often is missing is the economic link. How those changes play out when you consider feed production, milk income, and the overall financial health of the farm. I wanted to help fill the gap by putting field level data into a whole farm model. We can see how these conservation practices affect things like income over feed cost, cash flow, and long-term solvency. The reasoning is simple. Sustainability and profitability cannot be separated. And if we can show where those are aligned, that is powerful information for both farmers and policymakers. Okay, well, how how were you measuring the results? We looked at this from multiple angles. The foundation was the field trial trial data. Crop yields, forage quality, nutrient contents, and income and input costs collected from the long-term dairy cropping systems experience at Penn State's agronomy research farm. Those numbers were used to build rations and feed budgets for each system. From there, we ran the results through a whole farm financial model using FinPAC. We evaluated key metrics like liquidity, measuring by current ratio, profitability using a rate of return on assets and return on equity, solvency by using debt-to-asset ratio and term debt coverage ratio, and then income over feed cost, which is measuring the amount of milk income over the feed cost. By running simulations over two time frames, historic period from 2011 to 2017, and a more recent window from 2019 to 2023, we can see how these systems performed under different prices and weather conditions. The combination of biological, nutritional, and financial data gave us a full picture from soils to spreadsheets.

Jim Lawhead :

Well, how did the two models compare?

Josh:

Both systems support profitable dairy farms, but they were both performed differently under changing conditions. The broadcast manure with standard herbicide system tend to have a slightly lower cost in the short term, mainly because there's less fuel and equipment expense. However, it shows more volatility, especially in years when fertilizer prices and feed markets were unpredictable. The injected manure with integrated weed management had a higher upfront cost due to specialized equipment and labor, but it often paid off through better nutrient use efficiency and more constant feed quality. Over time, that stability translated into stronger financial performance. When we looked at income over feed costs, the injected system often came out ahead, particularly in years with tighter margins, and also the better long-term financial ratios, suggesting greater resiliency and less financial stress during tough years. So it's not that one system was always cheaper, it's that injected and integrated approach build a more stable, sustainable foundation for profitability over times.

Jim Lawhead :

Well, the most important question.

Josh:

The biggest takeaway is that sustainable practices can absolutely make economic sense when viewing from a whole farm perspective. Injected manure using integrated weed management aren't just about improving environmental outcomes. They can help stabilize feed costs, improve efficiency, and support long-term financial health. For farmers, this means thinking beyond just the year's yields. When you factor in soil health, nutrient savings, and feed consistency, conservation-minded systems can actually help protect profitability over time. In short, sustainability and profitability can work together, not against each other. If we can connect those dots, showing the practices good for land are also good for the ledger, we can help more farms stay both environmentally responsible and financially viable for the next generation.

Jim Lawhead :

I like hearing that. Well, how will this research and your education guide your future plans?

Josh:

This research really shapes how I think about dairy nutrition and whole farm management. My master's work at Penn State gave me a deep appreciation for every part of the dairy system connects, from how manure is managed in the field to the quality of the forage that is harvested, to nutrients that ends up in the cow rations, and finally to farms' financial performance. Going through this project taught me how to look at farms as integrated systems rather than separate pieces. The nutrition, the agronomy, and economics all interact, and when one changes, the others respond. The system thinking mindset is something I plan to carry forward in my career as a dairy nutritionist. I want to help farmers make rations and management decisions that not only balance nutrients for the cow, but also support soil health, nutrient recycling, and whole farm profitability. My education at Penn State, working with a multidisciplinary team that includes animal scientists, agronomists, and extension specialists, also prepare me to bridge communications between those areas. It is one thing to formulate a ration, it's another to explain how manure injection systems might improve feed value and reduce purchase fertilizer costs, and learning to translate research finding into practical farm ready recommendations. Looking ahead, I plan to work in the dairy nutrition field, ideally with a company or consulting role in Ontario, Canada, where I can apply these system approaches to support producers navigating environmental regulations, feed efficiency goals, and volatile markets. Ultimately, my goal is to be part of the next generation of professionals helping farmers make data-driven decisions that keep their herds healthy, their soils productive, and their business profitable for years to come.

Jim Lawhead :

Well, Josh, thank you very much for joining us, and we wish you good luck in the future. If you have any questions about today's episode or suggestions for future episodes, please email me at jbl5606 at psq.edu. And be sure to join us next week for the next episode of Bovine Banter.