Guests: Dr. Paul Kononoff, University of Nebraska-Lincoln and Dr. Logan Morris, Perdue AgriBusiness. Co-host is Dr. Clay Zimmerman. As we move into the fall and new silage is going into the bunkers, we wanted to take a closer look at energy metabolism and the mechanics of feed efficiency. Let’s talk about heat production and metabolism. Dr. Paul Kononoff joined us for a webinar on August 4th, 2021, to review the basics of energetics and new science that will help feed cows better. If you want to watch the webinar, go to Balchem.com/realscience.
Guests: Dr. Paul Kononoff, University of Nebraska-Lincoln and Dr. Logan Morris, Perdue AgriBusiness. Co-host is Dr. Clay Zimmerman.
As we move into the fall and new silage is going into the bunkers, we wanted to take a closer look at energy metabolism and the mechanics of feed efficiency. Let’s talk about heat production and metabolism. Dr. Paul Kononoff joined us for a webinar on August 4th, 2021, to review the basics of energetics and new science that will help feed cows better. If you want to watch the webinar, go to Balchem.com/realscience.
To kick things off, Dr. Paul Kononoff answers Scott’s question about how our understanding of energetics changed over the last 60 years. He explained the animals have changed dramatically as well as how we view energy when it is supplied to the cows. Feed characterization has changed since the sixties as well as NRC requirements of dairy cattle and how we measure it. (7:00)
Dr. Logan Morris discussed their study on factors that influence heat production. They found the two biggest factors were dry matter and body weight. Bodyweight represents the maintenance energy expenditure, which keeps the cow alive and functioning. Dry matter intake drives the rest of heat production. Higher dietary protein leads to more heat production and generates more milk protein which leads to more heat production. (15:04)
Dr. Logan Morris discusses the change in the industry over the past four or five years and how producers now face production caps and quota systems. He discussed his research on starch and fat and how higher starch increased milk yield. To produce a concentrated product for lowest milk volume, with maximum components, the study suggested feeding a lower dietary starch to prevent an increase in milk yield. (28:56)
Dr. Paul Kononoff discussed the effect energy mobilization of tissue has on feed efficiency. When looking at dairy cattle there are different physiological stages, different ages and different lactation stages. Feed efficiency can be extremely valuable and a useful proxy but can be misleading so you have to understand the conditions around it. (34:46)
Dr. Logan Morris discusses his research that shows starch and fat act differently when influencing milk protein production. (49:43)
Dr. Paul Kononoff is also participating in the new NRC release. You can view the five-webinar series from Balchem on the NRC at Balchem.com/RealScience.
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Scott Sorrell (00:00:07):
Good evening everyone, and welcome to the Real Science Exchange. The pub cast where leading scientists and industry professionals, meet over a few drinks to discuss the latest ideas and trends in animal nutrition. As we move into the fall, and with new silage going into the bunkers, we wanted to take a closer look at how best to meet the energy requirements of your cows. Hi, I'm Scott Sorrell, one of your hosts here at the Real Science Exchange. Tonight let's talk all about the dynamics impacting metabolism and feed efficiency. Dr. Paul Kononoff joined us for a very insightful webinar back on August 4th, 2021, titled: Feeding the Metabolic Race Car: a discussion on the use of starch and fat as fuels. If you happen to have missed that webinar, you can watch it at balchem.com/realscience. Tonight, we're going to dig a bit deeper into feeding that metabolic race car, and then we'll break down and discuss various components of feed efficiency. Dr. Kononoff, welcome back to the Real Science Exchange. Once again, you were with us a week ago and you're back now for your second trip. I, I trust that you enjoyed it.
Dr. Paul Kononoff (00:01:19):
Yeah. It's a, it's a pleasure to be back Scott, and thank you very much for the invitation. I'm looking forward to this discussion today.
Scott Sorrell (00:01:29):
Yep. So not only have you been to a two Real Science Exchanges, you also presented, as we discussed earlier a webinar. We're also going to have you back once again for one, in a series of five pod casts that we're going to be launching to discuss the changes in the new dairy NRC. So, Paul, thank you for your willingness to come here to the exchange with us and to share your time and knowledge with our audience. Now I understand you're our designated driver tonight, so you're not going to be drinking anything, but I also understand that there's a story behind your favorite whiskey, which is Jack Daniels rye. Looking forward to hearing the story.
Dr. Paul Kononoff (00:02:07):
Well, I don't know if there's much of a story, but just maybe consistent banter between myself, Logan, and actually Dr. Weiss who joined us as well at one time. I'm not a big fan of Jack Daniel's rye, but I do like rye whiskey. And, you know, if you had to ask me my favorite one, being a Canadian, I'd have to say Northern Harvest rye by Crown Royal. Probably trumps Jack Daniels.
Scott Sorrell (00:02:38):
Nice. I'll have to try that one. Yeah, so I see you brought a guest with you here tonight. Would you mind introducing him?
Dr. Paul Kononoff (00:02:46):
Yeah, this is really cool to have this discussion today with Logan Morris. Logan joined us several years ago from the Ohio State University- did his bachelor's and master's degree there. And it was just a blast to have him here at the University of Nebraska. I referred to his dissertation several times in that last podcast that you mentioned, and it, it really kind of reads like a up-to-date manual on studying energy metabolism. Logan spent his time here really kicking back some of the rudimentary traces of energy metabolism and how we'd measure it and what we know about it. And I think it's, it's great to see his papers now coming through the Journal of Dairy Science. In fact, I was just having a look at the October issue, and Logan's last paper actually shows up in the October issue of Journal of Dairy Science.
Scott Sorrell (00:03:48):
Songratulations Logan. Yeah, so Logan, thank you for joining us here to exchange. So tell us, what are you drinking tonigh, number one. Then how's it been working with Paul? And then I understand you finished up your research during COVID, so tell us a little bit about that.
Dr. Logan Morris (00:04:05):
Yeah, well, I appreciate you guys having, having me here on the podcast today and appreciate Paul inviting me along to be, to be a part of this. So for my drink today, I have a Woodford reserve double Oak via the recommendation of Paul, but to make it a little more interesting, I turned it into an old fashioned.
Scott Sorrell (00:04:24):
Very nice.
Dr. Logan Morris (00:04:27):
So really, really good drink and pretty good bourbon. So thanks for that recommendation, Paul. So yeah, I finished up my PhD last September, so it's getting pretty close to a year here and you're right. It was right in the middle of the storm of COVID and all of that that chaos. So, you know, and in hindsight it ended up working out pretty well. Cause I think I actually was able to get done a little bit early because of, because of all that. Because we had a little bit more time to dedicate to getting some of the writing done. None of us were traveling and I was able to kind of, kind of work from home and really focus on getting, getting the dissertation done and out there.
Scott Sorrell (00:05:06):
Wow, excellent. Dr. Clay Zimmerman, he's back once again, as our cohost- welcome back Clay. And what are you drinking, as if we don't know?
Dr. Clay Zimmerman (00:05:16):
I am back to my usual. It's getting towards the end of the season, but I have a watermelon hard cider here this evening.
Scott Sorrell (00:05:24):
All right. Let me ask you first. How long have you known Paul?
Dr. Clay Zimmerman (00:05:29):
Oh, quite, quite a long time. So, so we have a mutual colleague, Ryan Ordway. So I think, so I think I met Paul initially through, through Ryan actually. Because they they were colleagues at Penn state at one time.
Dr. Paul Kononoff (00:05:46):
Yeah. If I recall correctly of course we've got a good strong Penn State connection. Ryan and I were in the same office in our graduate work. He was actually at that time working on his master's, but then he and I worked at the University of New Hampshire together with Dr. Schwab. And I think, yeah, obviously you had connections there too, didn't you Clay?
Dr. Clay Zimmerman (00:06:11):
Yeah. So we, yeah. When you were working with the feed analysis consortium, we, you know, we had some interactions and as well. It's been about 20 years now.
Dr. Paul Kononoff (00:06:22):
It's hard to believe.
Scott Sorrell (00:06:24):
So clay, you asked me what I was drinking due. To the Ohio connection, Logan. You didn't tell us your, your pedigree, but I understand you've got a couple of degrees from The Ohio State University.
Dr. Logan Morris (00:06:35):
Yep, yes I do.
Scott Sorrell (00:06:37):
So I'm drinking a Balvenie, which is my go-to drink when I'm with Dr. Palmquist, and I'm drinking it as you can see from my Ohio State whiskey glass. So, and on our view there, Logan. Paul, during the webinar you went all the way back to studies from the 1960s. How has our understanding of energetics changed over the last 60 years?
Dr. Paul Kononoff (00:06:59):
Yeah, that's a good question. You know, I would say- you know, the interesting thing about energy is obviously cows need to follow the laws of thermodynamics. And so those laws have not changed. But what has changed is... well, we've seen some rolling undulations on just interest in energy metabolism. Sometimes it's a really hot area, and sometimes t's a lesser hot area. So, just the focus of study has changed. The animals have changed dramatically, and hopefully- actually we'll have Logan weigh in on that a little bit, but the animals have changed. And you know, how we're viewing energy and actually how we view energy when we supply it to the cows have changed. Feed characterization has changed dramatically over the last well, since the sixties, you know. And we'll be talking about that at the ADSA discover conference with the NRC requirements of dairy cattle, and how we measure it, how we look at it in our formulation software. There's been some big changes there. So you know, the, the question we can ask ourselves is, knowing the laws of thermodynamics and applying them to applied dairy nutrition studies, how do we go about actually measuring and studying energy utilization in applied dairy nutrition studies? And so you know, this may be a good time for me to ask Logan to jump in. You know, when you think about those fundamental studies that were conducted in the sixties, and even some of the things we're doing now, how are we measuring energy intake and energy flow from a technical standpoint?
Dr. Logan Morris (00:09:02):
Yeah. So it's interesting to look back on that research that was done you know, several years ago. Well, well before I was born, but it kind of laid the, laid the foundation for the energy system that we utilize today. It's like the NEL system was developed back in the, in the fifties and sixties. And, you know, from a, from a technical standpoint, the equipment has changed quite a bit today versus what, what was used several years ago. So back then they would, they would put a whole animal in an indirect calorimetry setup and try to measure gas production and gas consumption utilizing that system. And today, at least at the University of Nebraska, we were using head boxes to do that. So we would just put the cow's head and inside of a system to measure gas consumption and gas production. And, you know, a much smaller system, much more economical. And when we think it's a little more friendly to the animals, allowing them to be in a little bit more natural state than separating them off and putting them in a large contained system. So, so it's interesting how that technology has adapted so much over the, over the years,
Dr. Paul Kononoff (00:10:09):
Logan. So let's maybe just take a step back when you think about gas production and consumption. Why is that important when you're studying energy utilization? So, where do those measures come into play?
Dr. Logan Morris (00:10:26):
So we utilize those measures to calculate the amount of heat that a cow produces. And that's a pretty important component of the energy expenditure of a cow. If we look at total energy loss after feccal energy excretion, heat production is usually number two. So representing about a third of the, a quarter to a third of the dietary energy that a cow consumes is as lost as heat.
Dr. Clay Zimmerman (00:10:54):
So do the cows, do they actually eat with their heads in those boxes, the diets in that box?
Dr. Paul Kononoff (00:11:04):
Well, so one thing I will say is we've got a pretty nifty picture on actually one of the, one of the papers that will be posted describing maintenance energy in dairy cattle. So that, that should be posted on this webinar here. So there's a, there's a picture of the head box. For those of us that were born before 1990, we could say that that probably looks like a phone booth, and that's actually what the, the animal care workers downstairs, affectionately call this thing is, is a phone booth. So the cows stick their heads in a phone booth, but so Logan, how do we, how do we get a cow in a phone booth? And, what are we doing and what is she doing when she's in there?
Dr. Logan Morris (00:11:48):
Yeah, so it's always a little, you know, a little, a little bit of work to get them in there the first time. They're not necessarily a little bit resistant to going in, but once you, once you put them in there a couple of times and get them trained, they, they start to go in there pretty easily. And that's because they know their food's in there when they go. So when they get into the head box, they can start, start consuming that first meal. So the boxes are essentially steel- the whole bottom of it's steel, and that holds all of her feed for the day.
Dr. Paul Kononoff (00:12:19):
So it, you know, I would say when we operate those head boxes that, you know, one of the things I'm just struck with is just how miraculously adaptable these cows are that we work with. You know, whether we're talking about animals moving barns or pens on a farm, to going from a commercial dairy to a research metabolism unit, to our head confined in that. But Logan's right, if the, if the feed is there, the water is there, all of their comforts are there. In fact, this is a climate controlled barn. And so we've had producers in there saying, well, these cows are in paradise compared to, you know, what they could be facing in some of the conditions, as far as, you know, environmental temperature conditions in the real world. So when all of that's provided, cows miraculously adapt really quite well. And we see, you know, pretty average but impressive levels of feed intake and milk production. So, yeah, it's pretty neat.
Scott Sorrell (00:13:25):
Logan, did I hear you say that you're capturing gas production? And if so, are you characterizing that?
Dr. Logan Morris (00:13:33):
Yes, yeah. So we're specifically measuring oxygen consumption, CO2 production, and methane production. And that's all a component of calculating the, the heat production of of a dairy cow.
Dr. Paul Kononoff (00:13:45):
Quickly, Logan had mentioned research that was conducted before he was born. And there was a famous scientist with the last name of Brower. And, and what he's done is published an equation that says, okay, if you know oxygen consumption, CO2 production and methane production, you can then calculate how much heat is produced. And so it's kind of a big equation that's used in the field of energetics all over the place. So you asked about methane, I won't take Logan's thunder. Yeah, how much methane do these critters actually produce?
Dr. Logan Morris (00:14:27):
Probably somewhere in the neighborhood of 400 to 500 liters per day. And, you know, it depends on what they're eating and how much they're eating
Dr. Paul Kononoff (00:14:35):
And the breed. Obviously, we, we work with jerseys primarily. And so their feed intake to get back to the variable that Logan mentioned, their feed intake's lower. So their, their total volume of methane that's produced each day is a little lower.
Scott Sorrell (00:14:52):
So you, you mentioned that quarter to a third of the energy consumed by the animal is virtually wasted in and heat production. What kind of factors influence heat production?
Dr. Logan Morris (00:15:04):
So we did a, did a really interesting study where we looked at a bunch of different factors that influence heat production. We kind of found that the two biggest ones, and to no surprise, are dry matter intake and body weight. The body weight component represents the maintenance energy expenditure, which is a necessary component of, of maintaining and keeping the cow alive and functioning. It's lost as heat, but it's still an essential component. And then dry matter intake is the big factor that drives the rest of that heat production. And we can dig a little bit deeper down into that and try to understand how different nutrients and different milk components influence that as well. And kinda in general, you see the higher dietary protein leads to more more heat production and generating more milk protein, leads to more heat production compared to compared to synthesizing milk fat.
Dr. Clay Zimmerman (00:15:59):
So Logan, how does, I'm curious, how does, how does stage of lactation impact what you see here from an energy standpoint, and from a, from a feed substrate standpoint as well?
Dr. Logan Morris (00:16:16):
Yeah, that's it, that's an interesting question. We tried to look into that a little bit, but one of the challenges is the data set that we had was all post peak cows. So they, we didn't have any of the early lactation or peak peak lactation cows in the data set, which would have been really interesting to look at and see what's going on there. Could you shift around where that energy's coming from, right? Mid and later lactation cows coming from the diet, early lactation cows- a big proportion of that energy is coming, coming from the back. You would think that when they're mobilizing tissue, it would be more efficient than consuming it from the diet as far as the heat production standpoint. So you would expect a little bit lower heat production in those cows than you would in the later lactation cows that are consuming it from the diet. And that's just because putting milk fat or putting fat directly into milk is a highly efficient process. Whereas synthesizing some of those more components isn't quite as efficient.
Dr. Clay Zimmerman (00:17:14):
So Logan, you know, related to nitrogen utilization and energy utilization, have you done some work looking at the cost of excreting this excess nitrogen that we feed to cows?
Dr. Logan Morris (00:17:29):
So we looked at how urinary nitrogen excretion influences heat production, trying to get an understanding of the heat associated with that essentially excess nitrogen feeding that you're, you're kind of talking about here. And we know that as we increase urinary nitrogen, we're going to increase the heat production of a lactating dairy cow. And we've, there's been some debate, kind of, in the literature of what's the true cause of that. Some of it, the historical context says that it's because of urea synthesis generates quite a bit of heat, but there's some more recent arguments saying that that doesn't necessarily occur, but that extra heat is because of the catabolism of that excess protein. So converting that protein into other carbon skeletons and utilizing that within a dairy cow is a relatively inefficient process and leads to some excess heat production. Which can inherently influence the energy supply to a cow and and influence energy balance and in lactating dairy cows.
Dr. Clay Zimmerman (00:18:31):
So do you have an idea of how much, you know, how much energy that's costing?
Dr. Logan Morris (00:18:35):
Yeah. In the grand scheme of things, it's relatively small. We're talking about maybe a, maybe a megacal or two megacals per per day. So just a few pounds of milk, but it, you know, every, every little bit of it adds up and, you know, it can be a little bit of difference in effect the accuracy of trying to predict the energy value of different diets.
Dr. Paul Kononoff (00:18:56):
Maybe I kind of need to spend a little bit of time talking about Logan and I, we spent a little bit of time just poking around maintenance requirements of dairy cattle when he was here. Logan are you game? You measured maintenance at different, essentially different physiological stages, right? You want to talk a little bit about what we learned through that study?
Dr. Logan Morris (00:19:20):
Yeah. I don't know, in my opinion, the most interesting project I did during my PhD work was to measure, try to reevaluate the maintenance energy requirements and evaluate those on Jersey cattle. So we measured maintenance energy expenditure, both while cows were lactating and while they were dry and fasted. Kind of the backbone of the energy system is fasting heat production as an indicator of maintenance energy. And when you take a cow and fast her, get her to a complete fasting state, then she's just expending any energy to stay alive. And that's what really maintenance energy requirements are. The challenge with our lactating dairy cows is that it's hard to get them to a fasted state. Any of us, we could, we could go off feed for, you know, six or eight hours, and then we're already fasting, but dairy cow has a huge rumen that's continuing to supply energy to her once you remove feed.
Dr. Logan Morris (00:20:11):
So we had to fast cows for 72 hours to get them to a full fasted state, and then measure heat production during that time. And we kind of, kind of observed that heat production was not different between either- sorry, maintenance energy- wasn't different between either a fasted dry cow or for a lactating cow. So suggesting that those are relatively similar, but we did see that maintenance energy requirements are likely a little bit higher than they were in those historic studies we were talking about from the 1950s and sixties, and kind of what's used as the current backbone of the NRC system.
Dr. Clay Zimmerman (00:20:50):
So, so why do you think that those maintenance requirements might be higher now?
Dr. Logan Morris (00:20:57):
Yeah, there's a lot of things that, that can play into that. You know, we've selected cows for higher production, higher dry matter intake, and we've created a cow that has more metabolically active tissue per unit of body weight. We also have cows that are a little bit leaner today, too. So I think per unit of body weight to have more metabolic activity just as a whole leads to a higher maintenance energy requirement.
Dr. Paul Kononoff (00:21:25):
So one of the cool things, Logan, that you've talked about it pretty quickly. But you know, this whole notion of fasting cows for 72 hours, like when I think back, you know, you coming into my office and saying, Hey, I think we should do this. I mean, I think we all had a little bit of an angst around not feeding cows. Of course people go fasting for long periods of time, whether it's voluntarily or you know, pre-surgery or anything. But so like, yeah, we had these cows down here and they were fasting. Do you want to talk a little bit about like, just what we saw, like did they go bananas or, you know, were they healthy or what were our observations there? That's one thing that's obviously not in the paper, but I think it's interesting to talk about.
Dr. Logan Morris (00:22:09):
I mean, to be honest, I'm going to- when we, when we went into this, I thought it was going to kind of be a bit of a train wreck, right. You remove cows from feed for four days, and don't necessarily expect that to go well, but surprisingly it went, went relatively well. Cows seemed to handle it okay. They might've been a touch restless and a little, you know maybe a touch more nervous, but overall they handle it pretty well. Kind of one of the interesting things was that the cows definitely seemed cooler. So you, you can kind of see the hair standing up on the back of their, on their backs because they weren't producing nearly as much heat as they were before. And their heat production was probably a third of what it was when they were actually lactating.
Dr. Clay Zimmerman (00:22:48):
I was curious that, you know. So do they do, they become ketonic then, and how fast does it, does that occur?
Dr. Logan Morris (00:22:56):
Yeah, yeah. Well, yeah, they're certainly ketonic, cause they're just mobilizing body tissue to meet their energy requirements. You know, we didn't necessarily measure any indicators of that, but I don't know that it would be as ketonic as say an early lactation cow. Because they're not mobilizing or don't have nearly as much energy demand as that, as that cow. So that would be interesting to look at it a little further.
Dr. Paul Kononoff (00:23:20):
These cows were not, when we did the fasting heat production, they were not lactating. So yeah, so their demands were just basically the normal physiological demands of, you know, staying alive.
Dr. Logan Morris (00:23:33):
So Paul, I don't think I've ever asked you. When I came into your office with this crazy idea of fasting cows for 72 hours, what did you really think about that idea? To be honest, I kind of expect you to shoot me down pretty quickly.
Dr. Paul Kononoff (00:23:45):
Yeah, well, of course it's always fun to hear, you know, interesting ideas with good rationalization behind them. But I, you know, obviously I had read some of the estimates in the literature, and I knew it had been, you know, a while since, well, I know it had never been done with, with Jersey cows. And I was really game just to, you know, conduct that study and see what we could learn with that breed. And of course, it was as you know, I'm a kind of a historical junkie. And so to have that opportunity to compare some of our data to some historical measures. Logan, I think you remember you dug out the paper by Jim Holter from the University of New Hampshire that conducted a pretty similar study with, with Holsteins. And so, yeah, to me, it was, it was really fascinating to see how our data would compare against some of those studies.
Scott Sorrell (00:24:44):
Logan, you mentioned that in one of your comments back to Clay, something about tissue energy. How do we measure tissue energy?
Dr. Logan Morris (00:24:52):
Within our energy scheme, we are able to measure all the other energy expenditures of a cow, and all the other energy excretion. So we know how much goes into the cow, how much is lost in feces, how much is lost in urine, how much is lost as gas energy, and how much she puts into milk. And then tissue energy is essentially what's left over. So we're not technically measuring it within these studies, but being able to calculate it by difference. And we're able to do that by applying the first law of thermodynamics and knowing that energy is not created nor destroyed. So we have to have to, or know that all of that leftover energy is assumed to be tissue energy.
Scott Sorrell (00:25:33):
So that's where my mind kept going. Shouldn't we really be focused on how efficiently are we turning these things into animal protein. And I know that our fellow poultry producers and swine producers, that's a key metric that they're looking at. And so it was uncomfortable for me to think in just taking a look at the energy aspect of it. Just was kind of curious what, what your thoughts were there.
Dr. Paul Kononoff (00:26:01):
The thing is, and I mean, not to give you an academic argument, but if we look at efficiencies as expressing it as inputs and outputs, the dairy cow is just so complicated, right? There's different inputs, and different utilization and yeah, that's a challenge. It really is, when we look at dairy production,
Scott Sorrell (00:26:27):
I keep thinking, well, we could, you know, do a whole herd basis. But even when you do that, you don't know where to improve and what tweaks to make. And yeah, I just, yeah.
Dr. Logan Morris (00:26:38):
And I think, kind of a lot of the basis of our work was thinking about looking beyond feed efficiency and looking at energy efficiency rather than feed efficiency, because I think it's- from an academic standpoint, it's a little more telling as far as what's going on. It's a cow mobilizing that tissue energy to produce milk, right? And creating a misleading feed efficiency.
Dr. Clay Zimmerman (00:26:59):
Logan, I'm curious. Were you surprised at all in the, you know, the starch versus fat study? With the higher fat diet? That you weren't getting some fat accretion there, or that you had lot less fat accretion or not?
Dr. Logan Morris (00:27:16):
Not necessarily. I think, one of it's because one thing is that there's a difference in the energy supply and those actual diets when we measure it. So I don't think it's necessarily surprising that the starch drove more energy. And then, you know, fat accretion is partially an insulin driven response. So, increasing storage and driving insulin would signal for an increase in fat accumulation.
Dr. Clay Zimmerman (00:27:41):
Right, right.
Dr. Paul Kononoff (00:27:44):
Clay, you were asking about how the differences would have been by stage of lactation. Just a little bit of, you may find this interesting. So as you can imagine, it's really hard to find research funding to do something like that, like feed corn, you know, sources of energy. Corn, we're going to manipulate starch. And so that was one of those studies that actually was kind of funded out of just some residual funds that, that I had from different, different opportunities that we had along the way. Just turned out to be a really cool, simple study, only two treatments. And so you can make that comparison. But the animals were in that late stage of lactation, which of course makes up a big component of any dairy farm. But yeah, the question would be really interesting to see as, okay, well what would that look like in early lactation?
Dr. Clay Zimmerman (00:28:40):
So Logan, I, you know, I'm curious now that you've been out in the industry for a year now, what, what kind of learnings can you take from your work that you've, that you've been able to apply now in the in your career?
Dr. Logan Morris (00:28:56):
Yeah, one of the first things I think about, and I was thinking about this beforehand. We didn't delve into it during the podcast, but one of the interesting things is the world that we live in today has changed quite a bit than what it was four or five years ago. And from a milk production standpoint, we see that there's a lot of producers out there that are facing production caps and having to deal with those different quota type of systems. And from my research work, we did some work like that starch and fat study that showed that higher starch increases milk yield. Or if you have a production cap you want to produce as concentrated, you want to produce the lowest milk volume you can with the maximum components. So that study to the field, and you would suggest a feed a little bit lower dietary starch to try to prevent an increase in milk yield in cows.
Dr. Clay Zimmerman (00:29:51):
Without giving up milk protein?
Dr. Logan Morris (00:29:53):
Without yeah. Without giving it up. Trying not to, yeah. Right. So you want to produce five pounds less milk, but you know, an extra 10th or 2/10ths of milk protein. And we're still seeing around the country. I don't know if you guys are too,
Dr. Paul Kononoff (00:30:08):
So Logan, he's been out in the real world for a year now, right Logan? And you know, one of the things that you're doing is you're spending a lot of time with these different nutrition models. Whether they're the commercial ones or even the NRC 2001, and you'll be working through the next one. But, you know, if you have to think about energy metabolism, and actually quantifying energy use and requirements for lactating cows in some of these models, where do you think we could make some inroads to improve them even better than they are today?
Dr. Logan Morris (00:30:49):
We know that there's some areas that the science has shifted a little bit on as far as energy metabolism and some opportunities to update those, those energy models. Pretty much all of the energy models in the field, at least from a digestive, or post-absorptive metabolism, only utilize the NRC 2001 system. There's a little bit of a few differences between in, in the CNCPS system, a few tweaks to that. But in general, it's fairly similar. The NRC assumes that the conversion of ME- orh sorry, DE to ME- is essentially a constant and doesn't vary much with diets, but we know that's not really true. We know that as we increase crude protein, we're going to increase urinary energy loss. And that's not necessarily accounted for in those models. So we did some work. Paul and I, and some collaborations with some professors at Ohio State, tried to look at how increasing urinary nitrogen influences urinary energy excretion. Kind of trying to create a tool that can be used to model, model that, and be able to predict it from different diets.
Dr. Logan Morris (00:31:55):
And then as far as the net energy side, as we were talking a little bit earlier, we know that maintenance energy has changed. So there's some opportunity to update that as well. But we also have to look at how how efficiently a cow converts her metabolizable energy into net energy when we're considering those things as well. Another aspect of that maintenance energy work is that we've shown that cows today are a little bit more energy efficient than they were, then they likely were several years ago.
Dr. Clay Zimmerman (00:32:27):
So in one of your studies, you found that the NEL values, I think that this was, this was what you were comparing, the high starch diet from corn, which is the high fat, and your NEL values were quite a bit higher than what NRC predicted. Why, why is that?
Dr. Logan Morris (00:32:47):
Yeah, well, that, that was really an interesting finding from that study. And that's kind of what the first study I did during my PhD, and kind of kicked off the rest of the studies that we've been talking about. There's a number of factors that played into that. The diets were a little bit more digestible than the NRC said, so the DE was a little bit higher. And then the conversion of DE and into ME was greater in our observations than what the model said they would be. Some of that's because we were feeding a lower crude protein diet and the urinary energy excretion with a little bit lower. So there cows were a little bit more efficient there. And the biggest difference was the efficiency of converting metabolizable energy into net energy. NRC uses like a 64% efficiency, and these cows were approaching 70% overall efficiency. So that, that led to the higher overall NEL values on those diets. And then what was picked up in the, in the model.
Dr. Clay Zimmerman (00:33:45):
So how does, how does all this tie back to feed efficiency? We hear a lot about feed efficiency now, you know, becoming, you know... Certainly if we can improve feed efficiency that that can have a big economic improvement for the dairy. So how does all this work tie back to feed efficiency?
Dr. Logan Morris (00:34:09):
Yeah. Yeah, so that's that's an interesting and important applicable question. So as far as the change in maintenance energy requires, because those are a little bit greater today, I think it further emphasizes the importance in feeding for maximizing production to, to further dilute out those maintenance energy requirements and maximize our feed efficiency that way. The values we observed were about 20% greater, right? So putting, putting even more emphasis on feeding for maximizing production to dilute that efficiency.
Dr. Paul Kononoff (00:34:46):
You know the other thing about feed efficiency. I mean, I understand the value of studying that and tracking it. But I think, you know, the dairy cow is pretty unique or pretty special. Especially when you compare to, you know, a group of feedlot steers or feeder pigs that are all at the same physiological stage. You know there's, you have cows at different stages of lactation and Logan talked a little bit about tissue energy. Mobilization of tissue energy has a dramatic effect on feed efficiency. The most efficient cows you have in your herd are the ones that are losing weight. Well, so that's not necessarily saying that your ration is doing a good thing. What that shows you is some of the limitations on relying on feed efficiency as well. So yeah, I'm glad, I'm glad you brought up the discussion. I think feed efficiency can be extremely valuable and a useful proxy as, to use a term that some of my graduate students have used. But just an estimate. Just on that note, I used proxy. I threw it in there because I had a graduate student that used proxy a lot.
Dr. Paul Kononoff (00:36:00):
And I, I didn't like the term there just wasn't descriptive enough. But if I use it as a proxy, or an index of feed efficiency, it can be misleading. Certainly, you need to understand when you measure it, you know, what are the conditions around it? Are they very similar to the same conditions of the last time you measured it?
Dr. Logan Morris (00:36:25):
Right. So to kind of echo what Paul was saying, it's easy to measure feed efficiency, right, in the field. And maybe that has some drivers from an economic standpoint, but overall, we probably should be looking at energy efficiency of these diets to get a better indicator of what kind of things are going on from a metabolic standpoint.
Dr. Clay Zimmerman (00:36:45):
So you talked, you talked earlier. You know, one of the gases that you're measuring is a methane, and, you know, you talked about the 400 to 500 liters per day of methane that was being produced by these cows. So how much of, how much of an energy sink is that as a proportion?
Dr. Logan Morris (00:37:05):
In the grand scheme of things, it's relatively small. Off the top of my head, I'm thinking about 5 to 6% of gross energy intake. Does that sound about right Paul?
Dr. Paul Kononoff (00:37:15):
Yeah, yeah.
Dr. Logan Morris (00:37:15):
So it's relatively small, but it isn't, it matters at the end of the day.
Dr. Clay Zimmerman (00:37:20):
So if he were able to reduce enteric methane production, say by 50%. How much milk would that be worth?
Dr. Logan Morris (00:37:31):
Yeah, so if you could spare a few megacals of energy, and lead to a couple of extra megacals of NEL you can, you know, that'd be 4, 5, or six pounds of milk. But I think the big challenge is, can you, can you actually do that? Because we know that methane energy is positively correlated with digestibility. So there's some different strategies out there that may decrease methane, but they also decrease the digestible energy of the diets. And you might have a net wash there. There's also more, more work being done on feed additives that can inhibit methane production in the rumen. But the hydrogen that's produced in the rumen has to go somewhere. And we see that hydrogen gas production increases. Which in a normal situation, gas energy is 99% methane. So we don't necessarily care about the other energies or other gases that contain energy. But when we inhibit methane, increase hydrogen production in the rumen. And the cows blow that off in the gas fraction, we're shifting that portion around. So there's a lot of hydrogen energy loss too that we must, we have to consider when we're actually calculating gas energy and metabolizable energy supply.
Dr. Clay Zimmerman (00:38:49):
Okay, so Paul. This question came up during your lecture, but I'm curious to revisit the question about Jersey's versus Holstein's. So how applicable is the Jersey research to Holsteins?
Dr. Paul Kononoff (00:39:03):
Yeah. Well, so I think I've shared some of my thoughts in the last podcast. I'm going to maybe defer this to Logan and let's, let's hear, Logan's take on this.
Dr. Logan Morris (00:39:17):
Yeah. So when we, when we look at the data, we know certainly, or know there's differences between the Jerseys and Holsteins, as far as size and component production. But if we start to correct for those things, and we look at these energy data, relative to body weight or relative to like energy corrected milk production. We don't necessarily see a lot of differences between either a Jersey data set or a Holstein data set. So as far as we can tell, these data that we're collecting on jerseys should be applicable to Holsteins, but I guess the real answer is we don't know without necessarily comparing the two of them together.
Dr. Paul Kononoff (00:39:56):
So Logan maybe just talk a little bit about your observations on maintenance on Jerseys, and maybe what you observed compared to.. There, there have been some recent estimates of maintenance of other breeds too. So maybe just compare and contrast some of those things. Are they, are they, do they have lower maintenance?
Dr. Logan Morris (00:40:18):
Yeah. So there's some maintenance estimates out on some Holsteins out of Europe done about 20 years ago or so. And they were, they were relatively similar to the measurements that we picked up. So which again, would suggest that they're relatively similar in their, their energy requirements and, and, and energy metabolism. I think the biggest opportunity where there may be a little bit of difference is if we have differences in the milk fat to protein ratio. So if we have have Jersey cattle that are producing quite a bit more milk fat relative to that protein versus a Holstein. So, so pushing that fat to protein ratio up towards one and a half, they may be a little bit more energy efficient because we know that milk fat synthesis is more energy efficient than milk protein synthesis. Or more specifically, converting dietary fatty acids into milk fat is a relatively high energy efficiency process.
Dr. Clay Zimmerman (00:41:13):
So we're looking at it on an energy corrected milk basis there.
Dr. Logan Morris (00:41:15):
Yeah.
Dr. Clay Zimmerman (00:41:15):
Jersey's are a little more efficient.
Dr. Paul Kononoff (00:41:22):
So when we looked at it- yeah, go ahead, Logan. No, you go ahead.
Dr. Logan Morris (00:41:27):
I think we think they may be if they have a little bit higher milk fat to protein ratio, but in typical production situations, we don't necessarily see any differences there.
Dr. Paul Kononoff (00:41:40):
And certainly if you look at it as per unit of metabolic body weight, they're similar. You know, we didn't study this, but I know there's a lot of interest in the field looking at crossbred with Norwegian Red, Montbelairde, some of these other breeds. I'm not a geneticist, but it, it looks like the structure has developed very similarly, the body structure and body condition in Holsteins and jerseys, as far as composition. Obviously some differences with different breeds, but there's some similarities. Whereas when you look at like these Montbelairde crosses with Norwegian Red and Holsteins, there's some pretty, I think, dramatic differences in body condition score, wouldn't you say Logan? And so, you know, if you look at actually, you know-. A body condition score is-. We express maintenance as per unit of metabolic body weight, but all of a sudden now, if you've got some of these breeds that are carrying a little more condition, a little more fat, maybe there's some, some differences there because of the type of body condition that they're actually carrying around.
Dr. Logan Morris (00:42:51):
Yeah that kind of goes back to, we always have to remember that the most of the, at least the maintenance energy expenditure is primarily from lean tissue. So if they have a greater proportion of lean tissue mass, they're going to have a higher maintenance energy expenditure.
Scott Sorrell (00:43:05):
Your topic of your webinar was, you know, using carbohydrate and fats. How do you see those differently and how does a cow utilize those differently? And is there a preference one over the other? Does it depend on stage lactation? Can you expand on some of those?
Dr. Paul Kononoff (00:43:20):
So, I'll actually have Logan come in behind me on this. I mean, that really was the focus of the first study that you conducted here, is tracking energy flow when it came from good old Nebraska corn, versus maybe some rumen bypass sources. So do you want to maybe touch on the highlights that you observed in that study and how those may actually differ?
Dr. Logan Morris (00:43:47):
So we saw that when we fed diets that were formulated to have the same energy, but with more starch in them compared to compared to fat as an energy source. We increased milk production and increased milk protein yield via that avenue, and we think a lot of that was due to the differences in how those energy sources are utilized within the cows. So the starch can provide energy to the rumen and be utilized for microbial protein sentences and supply some amino acids to the cow that way and allow it to drive milk protein. You know, also the starch can supply glucose directly to the cow, and potentially drive an insulin signaling response indicating or upregulating milk protein synthesis that way. It's also interesting to note, and we talked a little bit about it earlier, that the higher starch diet actually had a little bit more energy in it when we measured it than not than the higher fat diet. So it may just simply have been an energy response. So increasing energy supply drove milk protein by just increasing the overall energy substrates.
Dr. Clay Zimmerman (00:44:58):
So how was the how was the corn grain processed in that study?
Dr. Logan Morris (00:45:05):
Yeah, so this was just fine ground corn from our feed mill that we use used to supply feed at the university. It certainly, yeah, the differences in processing could certainly have a huge effect on how these could influence a response here. So if we were to go to a more highly processed or more available starch source, like a steam flaked or a high moisture corn, that would just be primarily supplying more rumen energy and potentially influence microbial protein that way. But if you go to a little bit less ground corn, you're going to supply more, more glucose to the animal by getting some of that starch through the rumen and into the intestine and potentially driving a more of an insulin response. But then how does that influence the overall energy supply, right? If that's not quite as digestible as the other sources of starch. So, yeah, there's a lot of avenues that certainly need to be further explored. It's looking at how energy sources and feed sources influence milk production.
Dr. Clay Zimmerman (00:46:08):
So I'm going to ask you to speculate all this on. We talked about stage of lactation a little bit earlier. If you had run this study in early lactation cows, do you think you would have had the same outcome?
Dr. Logan Morris (00:46:23):
That's a good question.
Dr. Clay Zimmerman (00:46:24):
I have some thoughts on that. I think you would have, I don't know about the, I don't know about the starch versus fat question. We did some work- "we", this is 25 years ago in my career. We did quite a bit of research. First of all, with early lactation cows. These would have been cows like 30 to 110 days in milk, let's say, so cows around peak. And then we'd also run what we'd call mid lactation trials. He used to be cows like 120 to 200 days in milk. And we did some work looking at, at corn processing, actually. The early lactation cows: we could, we could bump up peak milk. So if there's more energy available to the cow, right she'll put that into the bulk tank basically. Because the cows in your study on that, on the high starch diet. They, they were creating fat, right?
Dr. Logan Morris (00:47:31):
Yeah, yeah.
Dr. Clay Zimmerman (00:47:33):
When you do that in mid lactation. So we actually sort of repeated some of these studies, or similar studies, early lactation versus mid. In mid lactation, of course, their lactation curve had already been said at that point, what we observed in those studies with increased grain processing, we didn't get a milk response. The cows actually reduced dry matter intake a little bit. So you improve feed efficiency, right? In that case. But, um, yeah, I don't, I don't know how the fat piece would have fit into that. But we had seen some of that from a starch standpoint. So yeah. Just curious your, your take on that.
Dr. Logan Morris (00:48:21):
Yeah, yeah. That's an interesting, interesting response; an Interesting idea. It' kind of supports the idea that the early lactation cows are relatively nutrient deficient. So if we increase energy or other nutrients, we generally see it in milk production in the bulk tank. And I think you could see the same thing when we increase fat in those early lactation cow diets. At least as long as it's a fat, that's not influenced in a rumen environment. You know, some of what the recent research would would suggest. Whereas in the later lactation cows, if you, if you modulate energy supply, it usually is reflected in tissue energy. So increased starch, increased energy that way. We see changes in body weight gain, or you know, increasing fat. You may see, may not necessarily see that in the bulk tank, but might see it on the you know, on the cows.
Dr. Clay Zimmerman (00:49:14):
Right.
Dr. Paul Kononoff (00:49:15):
So, you know, there's one of the things this has- and this is maybe switching gears a little bit, but there's a lot of interest, whether it's in the industry or research. And looking at amino acid requirements per unit of energy. And that's an intriguing concept. I don't know. What do you folks think of that concept and as far as setting requirements?
Dr. Logan Morris (00:49:43):
Yeah. So that's you know. Since I've left the academia world and started working out in the industry, we shift over from the NRC model to the CNCPS side of things. And that's kind of where they're at, as far as looking at those amino acid requirements. You know, it kind of makes sense to include energy in that, in that scheme, because we know that milk protein synthesis is an energy dependent process. But there's some interesting challenges that kinda come to mind, at least as it relates to this, a lot of the work that we did. We know when you're looking at grams of amino acids per megacal of ME, there's no designation on what that ME actually is. So our research shows that starch and fat act quite differently as far as influencing milk protein production. So I think what those energy sources are have a big influence on how you should be looking at these, these amino acid requirements. I'll see diets in the field, that'll be, be really high in fat, and they'll have a lot of ME in the diet because of that. Well, then that would suggest that you need to feed more amino acids to meet them, you know, as your requirements of those cows. But I don't necessarily agree with that, or you don't necessarily see that in production responses because that milk fat isn't not necessarily supporting milk protein synthesis.
Dr. Paul Kononoff (00:51:06):
And what about in group feeding? How useful is it to be looking at amino acids per unit of energy? You have any thoughts there? To me, that's where that's where there's a lot of questions, because you've got some animals gaining energy and some losing energy. Whereas I think, I think it just gets more complicated.
Dr. Clay Zimmerman (00:51:33):
So I, you know, I think my experience in the field would say, I think the concept is correct. I think in general we see more consistent responses to amino acid feeding in the field. Looking at at the you know, grams of metabolizable amino acids per megacal of ME. Rather than just feeding, you know, targeting gram amounts of amino acids. But Logan brought up a really good point: Where is that energy coming from? And that certainly makes a difference here too. Yeah, that's a great question. Yeah.
Dr. Logan Morris (00:52:12):
Yeah. And then on that same topic, I would kind of add that, you know, one of the biggest benefits I see of looking at grams of amino acid per megacal of ME is that it allows for a standardization of those diets essentially. You're essentially standardizing them to dry matter intake. And that removes this whole grams of amino acid thing that, that differs. You know, if we're talking about a thousand pound Jersey produces 60 pounds of milk or a Holstein cow producing a 100 to 120 pounds of milk, right, they're going to have very different frames of amino acid requirements. But you can look at the grams for megacal of ME and they'll be relatively similar- should be very similar- between those two different situations. So, allows them to be more, a little more consistent in recommendations that you're making for supplementing and looking at dietary amino acid levels.
Dr. Clay Zimmerman (00:53:01):
So, so Paul, that whole amino acid discussion, it brings me to the second study that, that you were talking about during the Real Science lecture looking at supplementing lysine. And in one of these studies, I'm curious in that, in that study, were there other amino acids that were limiting in that study? Or what would the next limiting amino assets have been in your opinion, beyond lysine?
Dr. Paul Kononoff (00:53:32):
So Logan went through all the exercises on formulating those diets. And I would say in general, you know, the aim was to make sure nothing was, was deficient. But and I know we're really gonna draw on his memory in formulations. But remember when you think about other amino acids, whether they were, or weren't limiting in those diets. Like, can you think of maybe the next generation of amino acids we should be looking at? What are your thoughts?
Dr. Logan Morris (00:54:03):
We spend all this time focusing on lysine and methionine for the last 20 years or so. And I think it's really time to start thinking a little bit beyond just those, those two amino acids. And those particular experiment, right, we were testing just lysine, but we did supplement methionine to make sure that wasn't deficient. But they were relatively lower crude protein diets. So then a histamine deficiency comes right to the forefront. We know that lower crude protein diets generally can be, can be deficient in histadine. And then there's kind of a, an evolving and growing body of evidence supporting other amino acids to stimulate milk protein production, or amino acids that we would call stimulatory amino acids, which would be like leucine and isoleucene, which signal and activate mTOR to potentially drive an increase in milk protein production. So there's a number of amino acids that could potentially be limiting or in that particular experiment, or that if we would add them to the diets, we could, could potentially see a response to those amino acids
Scott Sorrell (00:55:09):
As we close it up, then, I'd like to have each of you kind of give us, you know, one or two, perhaps three recommendations that nutritionists and farmers can take home in terms of improving the energy efficiency on the dairy farm.
Dr. Logan Morris (00:55:25):
Well I think kind of one of the biggest takeaways from my standpoint, and we've spent a lot of time discussing it today, is the differences in energy sources and making sure we're looking at those and evaluating those properly. So we know that starch and fatty acids behave a little bit differently in the cow from an energy standpoint and energy efficiency standpoint. And so, making sure we're looking at those appropriately, looking at starch as a relatively robust energy source to supply energy, both to the rumen and post metabolism, whereas fat is an energy dense source, and can supply energy to support milk fat production in dairy cows.
Dr. Clay Zimmerman (00:56:03):
Well, first of all, I want to commend Paul and Logan for really, you know, doing this type of research. Looking, really looking, deeper at energy utilization. It's, you know, this core work was done back in the, in the sixties. And I commend on doing this work to, to dig into this deeper. There are a lot of learnings here. So I think some key takeaways here are certainly- and Paul hit on this some during the Real Science Lecture- what role can grain processing play here? That can certainly impact things, depending on where you're located and, and the cost of these grains. So of course, Paul and Logan, you know, they're in cornhusker country. So corn tends to be less expensive there than when you get to the coast typically.
Dr. Clay Zimmerman (00:57:07):
So grain processing can play a big role here. Yu know, as far as energy utilization, I think stage of lactation can play a big role here and what we're looking at. And Logan hit on this at the end. I think there's still a lot to learn here from an amino acid standpoint and these interactions between amino acids and energy. So I'm actually really looking forward to the new NRC being unveiled here very shortly. So I'm curious to see what we learn, what learnings we have from that as well.
Scott Sorrell (00:57:47):
Paul, if we promise not the air this until after the discover conference, could you share a few tidbits with us?
Dr. Paul Kononoff (00:57:55):
No, I can't.
Scott Sorrell (00:58:08):
Alright, well if you're not going to give us to these secrets, why don't you go ahead and give us a couple, three practical things we can do on the dairy farm?
Dr. Paul Kononoff (00:58:15):
You know, and as Clay mentioned, we are in Cornhusker country, but I had a late friend. Many of your viewers may may know of Dan Kurtz, who was a nutritionist in Ohio. And he had this famous saying. I remember I was young in my career, but he had this famous saying: "corn is free". You know, and it, his point was, it wasn't necessarily free in Ohio, and all of these ingredients have their place. And trust me, he used them all effectively, but that like just coming out of grad school made me think, you know, we really need to feed the rumen and let the rumen microorganisms do their thing. And corn, in many parts of the world- not all- many parts of the world and countries is an economical source of energy, for driving the rumen bugs, rumen fermentation and energy supply.
Dr. Paul Kononoff (00:59:05):
So, so corn is free. That's that's maybe a takeaway. The other thing is, you know, it's interesting, as we start to poke around on some of these amino acids. Logan had a study showing that, you know, when you're feeding low starch, and maybe not feeding the rumen bugs, maybe some of these amino acids become short. And he had lysine, and that's kind of speculatory right now to see that. But I think it's could show, you know, a really could prove to be an exciting area of science, looking at some of these amino acids when corn isn't free and you've gotta be short. You know, now what do you got to look at to replace some of these amino acids coming from the bugs?
Scott Sorrell (00:59:43):
Great answer, great place to stop gentlemen. This lively discussion has certainly increased my metabolism and I want to thank you for the great discussion. You know, it's always exciting to see how new and exciting research can be applied, while keeping in mind that changing cow, feed pick characteristics and the environment. Also want to thank our loyal listeners for stopping by once again here at the exchange to spend some time with us. Hope you heard something new. I hope you learn something, and I hope to see you come back here real soon.
Scott Sorrell (01:00:12):
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