A simple question from a nutritionist sparked one of the most thought-provoking conversations we’ve had on Ruminate This.
If DON mycotoxins interfere with protein synthesis, how much milk protein could dairy cows be losing before clinical signs ever appear?
In this Letters from the Field episode, Dr. Larry Roth explores the hidden cost of nutrient chaos. How mycotoxins can redirect nutrients away from production and toward defense, affecting rumen function, liver health, reproduction, immune function, and overall performance.
If nutrients are being diverted from production to defense, what could that be costing your herd?
🎧 Listen now to set your herd up for lifelong success!
Scott Zehr: Hey, welcome everybody to another episode of Ruminate This with Agrarian Solutions. I am your host, Scott Zehr. And today, Larry, we are doing something that we’ve never done before.
I don’t know why it took me 70-plus episodes to think of this type of segment, but we routinely get questions from nutritionists or veterinaries, dairy farmers across the country, and a lot of times, Larry, we discuss them internally as a team and develop, okay, how, how can we best serve this person regarding this question.
But man, there’s some of these questions that we get from, say, the field that, I think people, people should hear the conversation that we have around this stuff. So-
Dr. Larry Roth: Yeah
Scott Zehr: … think of today as like a letters from the field episode. And so Larry, I’m gonna kick it right off with a text message that I received from a nutritionist. Just to frame it up for the listener, this message, the first message I’m gonna read to you guys was forwarded to me from the nutritionist. It looks like it’s a, an exchange between him and probably his tech person. And, then Larry, I’m gonna have some questions for you around this conversation.
Dr. Larry Roth: Okay.
Scott Zehr: so- hey, thanks for the question. DON inhibits the synthesis of protein, therefore likely negatively impacts microbes, which trials have shown lower microbial protein production and lower fiber digestibility. Post-ruminally, DON is tough on the gut health. I don’t know if that’s a function of protein synthesis or by other means. I would have to go back to my notes regarding site impact for Agrarian’s DTX product.
If it does have some activity within the rumen, that could improve rumination. A cumulative effect post-rumen makes sense as well. And then the specific question I received from this nutritionist, “As we try to make more milk protein, I’m wondering how negatively DON is working against us.” That’s what started this whole conversation.
Dr. Larry Roth: Right.
Scott Zehr: The farm I’m referring to has a 13 PPM DON. So at least they’re, not starting with 500 parts per billion or .5 PPM, Larry. Wow, there’s a lot of meat on that bone from a, from a few different places, and I, I think, Larry, where I’d wanna start with, with our conversation today is more on the protein synthesis side.
My question being, if DON is inhibiting protein synthesis, what’s actually happening inside the cow to cause that? And then I’ll… I have some follow-up questions for you as well.
Dr. Larry Roth: Okay. Excellent. So in a previous session, we had called DON the disruptor mycotoxin.
Scott Zehr: Yes.
Dr. Larry Roth: And I think that’s a good lead in here.
So DON alters the rumen microbial population. So if you don’t have bacteria who are fermenting the diet, creating energy, making nitrogen available to be converted into microbial protein, which is the am- ideal amino acid balance for the cow, you don’t have the ideal amino acid balance being absorbed. I think that’s one place.
The other, there’s some thought that the DON molecule may inhibit some of the actual protein synthesis within some of the cells. So if you’re not absorbing the ideal amino acid balance and then you’re inhibiting actual protein synthesis itself in the cells, you’re not gonna have the milk protein created, you’re probably gonna have l- less lean tissue, you’re probably gonna have less of the important organs such as the liver and the kidneys.
And so it’s just kind of a cascading effect, if you will. And it, to me, I think with ruminants, we always have to start with the rumen. They’ve been blessed-
Scott Zehr: Yeah
Dr. Larry Roth: With this 55-gallon fermentation vat between their ribs, and we want that fermentation to be as, both energy efficient and nitrogen efficient as, as it can be, because that sets the stage for the whole rest of the animal.
Then we have to go to the small intestine, and DON can reduce gut integrity at the small intestine, but now we gotta rebuild that small intestine. And by the way, we’re, we need some amino acids, some protein to rebuild that gut tissue. So again, it’s kind of a, if we wanna call it a cascading effect.
This happens, it inhibits this from happening, that makes it harder for another thing to happen. But it all-
Scott Zehr: Yeah.
Dr. Larry Roth: starts with what’s going on in the rumen, and then what happens to gut integrity in the small intestine.
Scott Zehr: And I, I appreciate your call back to that episode as well, where we previously, nicknamed the different mycotoxins DON being the disruptor. And, and really we, we used that analogy then of all of these things flow downstream.
Dr. Larry Roth: Yeah.
Scott Zehr: So, you know, one of the questions I had thought of is just, what happens first? Does the rumen get compromised or the gut gets compromised, right? The small intestine. And obviously, based on what you said, we’re first gonna see efficiency drop in the, in the rumen, and that’s where-
Dr. Larry Roth: Yeah.
Scott Zehr: That’s where the fermentation vat lives.
Dr. Larry Roth: Yeah.
Scott Zehr: But again, so the gut health side of that plays into it as well.
Dr. Larry Roth: Yes. Yeah, so I’m gonna say we lose efficiency, both energy and nitrogen efficiency in the rumen first, and then we have issues with small intestine integrity. I, I think that would be the, the proper order.
Scott Zehr: Yeah.
Dr. Larry Roth: maybe I don’t wanna say proper order, but the, the sequence for these challenges occurring.
Scott Zehr: So Larry, right now, people are trying to feed for more milk protein, so-
Dr. Larry Roth: Yep …
Scott Zehr: I I, don’t know if we can really put a number on it, but if we’re trying to maximize milk protein production-
Dr. Larry Roth: Yep
Scott Zehr: Like, how much could DON be maybe quietly working against us before we ever see clinical signs like loose manure or erratic intakes?
Dr. Larry Roth: Wow, that’s a good question. Again, I’m gonna take you back to our past podcast. Are there other mycotoxins challenging the cow at the same time?
Scott Zehr: Mmm.
Dr. Larry Roth: What is the level of DON? What other challenges might the cow be, be facing? So your, your question was what is the… you were trying to put a number on the- I, yeah, I mean- … reduction in efficiency in…
Scott Zehr: Yeah, it’s, it’s probably a hard thing to do i- in a way, right? But-
Dr. Larry Roth: Yeah …
Scott Zehr: I guess the spirit of the question is we inherently know based on research, based on things that we’ve talked about on this platform, DON inhibits protein synthesis, right? And there’s a- downstream effect. I’m just imagining, we’re out there in the real world trying to feed the cows to, to increase milk protein.
Dr. Larry Roth: Yes.
Scott Zehr: And we keep throwing ingredients at it, and we keep changing strategies to try to maximize it. We have genetics that have, gosh, have elevated the cow’s ability genetically speaking to make milk protein.
But Larry, if I told you that there was a farm that was making, their percent protein was 3.6% protein, that’s pretty good. And that was a number that was good years ago too. It just, what is holding that back?
Dr. Larry Roth: From a higher level of, of protein in the milk, perhaps amino acids in the diet and perhaps the ratio of those amino acids. That could be holding them back. And also where else is that protein having to go?
If that protein is being diverted to rebuilding digestive tract tissue, if that protein is being reallocated to repairing liver damage because the liver’s doing a lot of detoxification and other issues are, are going on.
So what all challenges is the cow facing? So there’s a, s- slide that I’ve used at different times that looks at the interaction of maintenance, reproduction, milk production, and then defense, which could be the immune system, it could be reestablishing gut integrity. And when we have metabolic challenges, and I’m gonna go ahead and say social challenges, environmental challenges, the nutrients reallocated to defense grows. Okay? And so if more protein in this situation, this example, is diverted over to defense, we’re not gonna have the milk protein that we could potentially have. If defense wasn’t-
Scott Zehr: Yeah, I’ve-
Dr. Larry Roth: soaking up all that protein.
Scott Zehr: Yeah, I, I feel like we’re maybe starting to sound like a broken record, ’cause I, I think you and I have been talking about nutrient reallocation it seems like for, for the better part of two years.
Dr. Larry Roth: Yeah, yeah.
Scott Zehr: or, or longer, but on this platform. But it, it’s-
Dr. Larry Roth: I, I really think, Scott, that is what limits nutrient efficiency, milk production efficiency. Where are those nutrients going? Because at, at the end of the day, the cow has a limited amount of nutrients to work with. Okay? She’s eating, for the sake of discussion, 56 pounds of dry matter, 60 pounds of dry matter, I don’t know. and there’s a certain n- nutrients that comes with that.
Well, what percentage of those nutrients get absorbed as energy, BFAs? What percentage of the nitrogen or amino acids she consumes end up as microbial protein or feed protein for her to absorb? Okay? There’s some number for both of those. I think the question is where do those nutrients go in her body?
And different things are gonna cause reallocation of the nutrients, and ultimately it’s that reallocation that affects efficiency. So Scott, if we were to go to a dairy that’s got, oh, man, they’ve got absolutely fantastic, feed efficiency, turning, turning feed into milk, I’m gonna submit to you that that is a dairy that does not have a lot of inflammation going on, that probably does not have major mycotoxin issues.
There’s fires that show up, okay? But that dairy is able to put those fires out rather quickly. So that now nutrients go to more profitable purposes than just maintenance and defense. And so you see what we’ve also done here, Scott, is we’ve broken maintenance away from defense.
Scott Zehr: Yeah.
Dr. Larry Roth: And I think many times people will put defense under that umbrella of maintenance.
Scott Zehr: Yep.
Dr. Larry Roth: I think we need to separate defense from maintenance.
Scott Zehr: I think that’s fair and, you know I’m, I’m just imagining, I’m trying to, just imagining myself being a nutritionist for a minute and laying down in bed trying to connect all these dots and, and that’s, maybe that’s just giving the listener a little, too much of how my brain works.
I, I tell people my brain’s like a pegboard and it’s covered with pegs and I, I have to make sure all the strings that can connect do connect if they can. And just walking through the cause and effect of this type of conversation, Larry, it would wake me up with night sweats to think that there’s stuff going on that, that is influencing the effectiveness of the ration that I’m putting on paper. And now one, it’s one thing to recognize that. It’s another thing to figure out then what those things are.
Dr. Larry Roth: Yep.
Scott Zehr: But we know, bringing this back, we know that some of those things are mycotoxins.
Dr. Larry Roth: Yep
Scott Zehr: What are we doing about it? So there was another part of that, that letter that I had read that asked, or that, that the comment was in the message, I would have to go back and look through my notes, and I’m quote, quoting here, “I would have to go back and look in my notes to see what impact DTX has on the site.”
It’s speaking of the small intestine or- or even potentially in the rumen. Maybe let’s walk into that a little bit, because I, I think, you know, at the end of the day, we’re trying to make more mo- more milk protein. DON’s potentially inhibiting us from doing that. We have something that works on DON. So walk us through a little bit of how that actually happens.
Dr. Larry Roth: Okay. I think when I look at how, how DTX works, it’s defending gut integrity, so you don’t have as much destruction of digestive tract lining cells. So you’re gonna have more nutrients, both the amino acids and the energy that would be required to rebuild the gut tissues that are now gonna be available for more productive purposes.
You don’t have, not only DON, with your question. But you don’t have other pathogens entering into the body to cause issues with not only the liver, but the kidney as well. So you don’t have the nutrients going to rebuild those tissues. You don’t have, DON or other, pathogens going through the body for the immune system to attack against, or to attack, rather.
And so those nutrients are gonna be… Those nutrients that would’ve gone to defending and protecting are now available for more profitable purposes. So again, it’s a cascading effect, this time in a positive direction. We’re able to protect against DON at the gut level, so all of these other good things happen.
And because this happens, then this good thing happens, then this good thing happens. So now we have a positive cascade or chain of events.
Scott Zehr: I’m, I’m gonna… I like where you, you went with that from a positive cascade, so I’m gonna kind of circle back a little bit and talk about the, the cascading effect of DON-
Dr. Larry Roth: Yeah.
Scott Zehr: from a negative light, right? But I, Larry, you have a, a farm enterprise with beef, with chickens, with pork as well, I believe.
Dr. Larry Roth: Yep, yep.
Scott Zehr: And maple syrup.
Dr. Larry Roth: Yeah.
Scott Zehr: So- if there’s a little bit of chaos happening around the farm things don’t necessarily go smoothly.
Dr. Larry Roth: Correct, yep.
Scott Zehr: What maybe should have taken you two hours to do chores now took three.
Dr. Larry Roth: Yep.
Scott Zehr: We didn’t have something happen that just blew up the whole farm, but just little things all of a sudden don’t work quite as good.
Things don’t flow quite as good. And, you know, I think so many times when we get into conversations about mycotoxins, and DON specifically, we say, “Oh, are the cows showing signs of, you know, loose manure?” What’s the intakes like? What’s the…” wait a minute. If DON is a disruptor toxin, as we’ve called it-
Dr. Larry Roth: Mm-hmm
Scott Zehr: Maybe we’re thinking about this in the wrong way. Instead of DON causing a specific issue like digestive upsets, going back to, the, the analogy there of, of a little bit of chaos-
Dr. Larry Roth: Yep …
Scott Zehr: can just disrupt the whole program, maybe we need to be thinking about DON as, more of a just biological efficiency reduction agent. That’s a really mouthful way of saying that. But e- expand on that, if you could, a little bit.
Dr. Larry Roth: Okay. So as, as you were talking, what was going through my mind, the word of the day is either cascade, ’cause I keep using that, this happens or this happens or this happens, or it’s chaos. Okay?
Scott Zehr: Yeah.
Dr. Larry Roth: So as I have in my career, both professionally and otherwise, traveled around the world and been to a lot of farms, ranches, dairy operations, beef operations, pork, poultry operations, those who are successful get things done on a timely basis.
That’s time allocation. When chaos happens, time allocation is messed up and things don’t get done on a timely basis. Rather simplistic. But I think that we can look at, here’s a term for you, Scott, how about nutrient chaos?
Scott Zehr: Yeah.
Dr. Larry Roth: When chaos happens in the cow’s body, mycotoxins, we could say leaky gut, we could say heat stress. We could continue on, but when that chaos happens, nutrients are now reallocated from where we wanted them to go.
Scott Zehr: Yeah.
Dr. Larry Roth: So, nutritionists can say, “All right, how much lysine does a cow need?” it depends what she has to do with it. If she’s having to divert some lysine to gut rebuilding, her requirement just went up.
So, maybe a term that we could start using is nutrient chaos, which comes from metabolic and environmental and social challenges. And the cow has to resolve that chaos if she wants to live. And if she doesn’t-
Scott Zehr: Yeah.
Dr. Larry Roth: resolve it, that’s unresolved inflammation, that’s unresolved other things. She doesn’t make milk. She doesn’t get bred back. Maybe she doesn’t live and she’s not on the farm. So our word for the day could either be cascade or chaos. How’s that?
Scott Zehr: Yeah. And they, there’s some symmetry between those two words in this-
Dr. Larry Roth: Yep.
Scott Zehr: …context as well.
Dr. Larry Roth: Yep. Exactly.
Scott Zehr: All right, Larry, I’m, I’m gonna do something a little bit different here as we wrap up this conversation.
Dr. Larry Roth: Yeah.
Scott Zehr: we’ll call it a lightning round, if you would. Okay. So I’m gonna, I’m gonna ask you to finish this sentence in a fun, rapid-fire way. Here we go. The biggest misconception nutritionists have about DON is…
Dr. Larry Roth: that it happens in a vacuum by itself. So often DON is gonna be traveling hand-in-hand with other mycotoxins. And again, it starts this cascade of events.
Scott Zehr: Okay. question two: The first number I look at when evaluating a DON challenge is…
Dr. Larry Roth: Hmm. Total parts per million of DON.
Scott Zehr: Okay.
Dr. Larry Roth: Second would be what other mycotoxins are there.
Scott Zehr: Question number three, a farm can have a DON problem even when blank.
Dr. Larry Roth: Even when the DON level is low, because there are other challenges are taking place that reduces the cow’s, or increases the cow’s susceptibility to DON.
Scott Zehr: And lastly, the most overlooked consequence of DON exposure is:
Dr. Larry Roth: Liver function.
Scott Zehr: Hmm.
Dr. Larry Roth: We think of DON as messing up, there’s a scientific term for you. Messing up ruminal fermentation, destroying gut integrity. But we don’t necessarily think of DON as impairing liver function. But if these other things, altering ruminal fermentation and increasing or decreasing gut integrity take place, there’s gonna be greater loads on the liver, and liver function is gonna suffer.
Scott Zehr: So if the chaos cascades.
Dr. Larry Roth: There you go.
Scott Zehr: I only did the lightning round so I could work that in.
Dr. Larry Roth: All right.
Scott Zehr: I’m just kidding. I’m just kidding. I think there’s a, a lot of meat on this bone that we could probably dive into. And folks, if you have questions regarding this topic or any, any topic involving, the dairy industry really, but specifically, Ruminant Nutrition [email protected]. Ask us your questions. We will get back to you personally, and you never know, it may turn into a Letters from the Field episode with Dr. Roth.
Larry, I wanna thank you for taking time out of your day today to have this conversation. I think there’s some, some good nuggets here for people to think about and, and maybe thinking about old topics in a new light, and I’ll give you the last word.
Dr. Larry Roth: Yeah. The last word would be just think of the chain of events, the cascading effect that comes from not just mycotoxins, but other challenges as well.
Scott Zehr: Love it. Have a great week everybody, and we’ll be talking to you again soon, from the podcast room here at Agrarian Solutions and Ruminate This.
