In this episode of Ruminate This, host Scott Zehr interviews Dr. Larry Roth to address the growing problem of mycotoxin contamination in dairy cattle across the U.S. Dr. Roth shares alarming 2024 corn silage data from the Northeast, Great Lakes, and East Coast, highlighting the presence of multiple mycotoxins at concerning levels. He also discusses the increasing detection of DON (vomitoxin) and Zearalenone, typically “cool weather” toxins, in southern states, as well as the mycotoxin risks in the western and southwestern regions.
The episode provides insights into the “Big 5” mycotoxins—DON, Zearalenone, Aflatoxin, T2/HT2, and Fumonisin—which are known to negatively affect dairy cattle’s production, reproduction, and immune function. Tune in to discover strategies for improving dairy herd health, boosting milk production, and mitigating mycotoxin risks.
🎧 Listen now to set your herd up for lifelong success!
Get the Mycotoxin Report here.
Scott Zehr
Hey, welcome to Ruminate This with Agrarian Solutions. I'm your host, Scott Zehr. And today, Larry, this is going to be like hot off the press kind of stuff for us. Which is something we don't always get to do here at Agrarian on Ruminate This. But today we are unveiling to the public our mycotoxin report that you just finished finalizing. And we're going to kind of go through that a little bit share with the audience some insights of what the toxin levels we're seeing.
Not just the data that was collected March through September, obviously that's going to include Larry, some 23 corn as well. But, we have had some samples of freshly harvested 24 corn silage samples come in. And we're going to kind of talk about what we're seeing as a trend there, within today's conversation.
And once again, joined by our Vice President of Nutrition, Dr. Larry Roth. So Larry, I appreciate you getting all of this data put together for us. You've had kind of an October already, World Dairy Expo, and then trying to get this project done to keep me happy. I appreciate you putting in the extra time and effort to get it done for us.
Dr. Larry Roth
Oh, it's good to get to put these numbers together, Scott, because everybody is always wondering how have mycotoxin values been going? We watch them come in all of the time, Scott. Plus we're also looking at what's coming ahead. So I think we'll have a very interesting discussion today.
Scott Zehr
So you know, let's dive in a little bit of, why we put this report together. What value is it to the listeners? When they see this come out in the RISE Newsletter or in our online kind of stuff. Like what is it really telling us?
Dr. Larry Roth
You bet. Well, I think we like seeing this report and putting it out and people enjoy reading it for several different reasons. Number one, you know, otherwise, we're just looking at samples results on a day by day basis.
We need to put things together and really see what is going on. Look for trends over time. Second, we like to see how different regions of the country compare. And that comes from a couple of reasons. We're, by nature, comparison people. But it also gives us an idea of what's happening milk production wise across the country.
The more mycotoxins affect a certain part of the country, the more it can affect production and reproduction in that area. Plus, with the feed industry the way that it is today, we're moving certain feeds around the country.
And so, if we're having a lot of mycotoxin issues in corn silage in the Midwest, for example, there's going to be byproducts coming out of the Midwest that's going to cause challenges in other areas. So I think the mycotoxin report has a lot of value to different readers for different reasons.
Scott Zehr
Yeah, that's a good point about, you know, just look the corn moving from one part of the country to the other, and. So Larry, as I was looking at this report one question that I have is how many samples are represented here? Roughly.
Dr. Larry Roth
You bet. I believe that with the corn silage, we have 303 TMR samples, and 505 corn silage samples.
Scott Zehr
Okay. So pretty good, pretty good level there. So for you, before we dive into some of the individual states or regions, I'm curious if you could summarize what your takeaway from this would be for the listeners.
Dr. Larry Roth
You bet. My basic takeaway is that DON persists as being a challenge for the northeastern third of the country. I think that we're starting to see some drought effective samples come in from Pennsylvania, Virginia and North Carolina. And we're starting to see some high fumanicin levels there, and we'll talk a little bit more about some particular states.
But, you know, we've always talked about fumanicin as being more of a warm to hot weather mycotoxin, and we see that show up. Coming out of some drought prone areas. We talk about DON being a cool, wet weather mycotoxin, and we see that. But I'm going to go ahead and jump ahead here and say that we picked up DON in TMR samples in the state of Georgia.
And normally we wanted to anticipate that, but again, we see that DON can show up in different areas and DON also can travel in by product feeds.
Scott Zehr
Yeah.
Dr. Larry Roth
So there's, there's a variety of interesting trends that we see in the samples.
Scott Zehr
I guess what to you is concerning when you look at Maybe just starting with DON is there a particular area of the country, well, you said the northeastern third of the U.S., but state by state, I mean, how does that shake out? And maybe just expand on what can we do about it?
Dr. Larry Roth
Okay, great question. Well, interestingly I said the northeastern third, we're also starting to see some high DON levels from South Dakota, Minnesota, and Wisconsin as well. So what, can we do for DON? You know, the emphasis in the past has been hybrid selection. We don't want to leave the crop out there in the field too long. Let's get it harvested on a timely basis.
We've also done a lot of looking at fungicides. And we've been involved in some fungicide research at Ohio State University. And, one of the basic things to come out of that is, it all depends. We have hybrids that are more on the conventional side, in other words, not GMO.
They tend to quite often, and I sure hope I don't step on any toes here, but a lot of these conventional hybrids seem to be a little bit more susceptible to weather variations, be it dry early on or wet early on, or the reverse at the end, wet and/or drought. Anything that challenges the plant seems to tip the balance toward the mycotoxins. And that can be too hot, that can be too cool, that can be too dry, or too wet.
Scott Zehr
Yeah. You know, looking through some of this, I'm, I'm seeing Michigan, Indiana, Illinois, New York, all pretty high in DON. You know, the interesting thing about, I think when I look at this report, so the states that have the highest levels of DON in particular, tend to also have Zearalanone, and T2, and Fumanicin, all at the same time. Maybe touch on that a little bit.
Dr. Larry Roth
All right. Well, I would agree with what you said for the DON and Zearalenone. They seem to travel hand in hand together. For example, when we look at corn silage, we're seeing kind of the Great Lakes and the Northeast having high DON, and then being in the medium risk level for zearalenone. And then New York and Vermont being high risk for zearalenone in the corn silage. So again, we think of both of those being cool, wet weather mycotoxins.
And again, we talk about ranges and the risk level. And it all depends on what other factors the cow is dealing with. So when you have multiple mycotoxins showing up at the same time, it's kind of exacerbating the problem. It's putting the cow at greater risk. So all of these levels, Scott, and I think this is an important note here, all of these risk levels are based upon if this was the only mycotoxin we're dealing with.
Scott Zehr.
Yeah
Dr. Larry Roth
But as you just brought up, we're dealing with DON and we're also dealing with zearalenone at the same time. So big challenges come in. We probably had more fumanicin this year than previous years. And so these areas that are high DON, high zearalenone, and high T2. Some of them were average for fumanicin, like the Great Lakes States.
But then again, Pennsylvania, Virginia, North Carolina, be in the high fumanicin area. So some of these are getting the trifecta, three high mycotoxins. Some unfortunately are getting four high mycotoxins.
Scott Zehr
Yeah, just looking at Vermont, for example. I mean, this is the corn silage. You know, over 2000 parts per billion on DON, over 300 parts per billion of zearalenone, 269 parts per billion at T2. And then even fumanicin coming in at 7.17 parts per billion is a considerably high number kind of in that medium risk or medium contamination, if you will. You know, so I guess, Larry, we touched on the hybrid part of it. Is this mostly just weather pattern related? Do you think?
Dr. Larry Roth
That's a great question. Why are we seeing these levels? I think there's a variety of factors that come into play. Certainly weather has an issue there. I think it also has to do with our cropping practices, greater planting densities, greater canopy, level of hybrids to resist some of these challenges. And then once we start getting some of these molds present in the crop, they tend to stay in the soil.
And so as soon as that little green plant, that little coleoptile, the first leaf emerges through the soil, it becomes infected. And so the mold, the fusarium mold, the penicillium mold just sits there on the leaf as the plant matures and develops, just waiting for that right opportunity to take off and produce the mycotoxins.
So, we just see to get certain parts of the country that these problems are there. And I think also we're starting to see certain fields that it's just gonna be there. And I hate to say it, but for some parts of the country, this is gonna be a perpetual issue year after year. I think, Scott maybe a little bit related to the hybrid issue, we saw only one state that registered any level of aflatoxin, and that was a low level.
So you think about how certain parts of the country did have drought this year. But they didn't have aflatoxin. So these corn hybrids today are a lot more drought tolerant than what they have been in the past. And again, if the plant gets stressed, then we start to see molds grow and the opportunity for the molds to produce their mycotoxins.
So I'm going to tip my hat to the corn breeders in saying that we have got more drought tolerant hybrids and consequently we're not seeing the aflatoxin like what we may have seen in the past. Now, on the flip side of that, where we do see aflatoxin, it's going to be quite often where we have cotton byproducts being fed.
Because cotton is not quite often grown in more drought prone areas. And the cotton crop, maybe isn't quite as drought tolerant as the corn. I want to be kind of careful in how I say that. But when we start feeding a lot of whole cottonseed from certain parts of the country, we may be increasing our aflatoxin risk.
Scott Zehr
You bring up the aflatoxins. So I'm going to throw a call back out here to episode 14 that you and I did. We talked about mycotoxin binders proven to bind more nutrients than mycotoxins. Within that episode though, we do discuss some of the things about aflatoxin in the sense that we really don't see it around anymore. And as you just said, we had one sample come through out of 500 corn silage samples and 303 TMR samples that had aflatoxin. And I think that's something, you know, to keep in mind.
Dr. Larry Roth
And for that matter, Scott, it didn't even make our report because we just don't see it. And that sample was at a seven part per billion in the TMR and came from Georgia.
Scott Zehr
Yeah. Yeah.
Dr. Larry Roth
Where we quite often see some cotton products being fed.
Scott Zehr
Sure. So with this report, Larry and, you know, you folks are hearing about it here first. We're going to, it'll be in our rise newsletter. You can find that on our website. Our rise newsletter is going to be out, I think in a couple of weeks, Larry.
And so if you're on our email list, you'll be getting this emailed to you as well. If you'd like to be on our email list, just go to our website and fill out the form. And, you can do that quite easily.
But if I'm a producer, Larry, let's put our producer hat on for a second. What can I actionably take away from this as far as how I make decisions? Whether it's purchasing corn, whether, you know, what can I do with it?
Dr. Larry Roth
Great question, Scott. So I come back to who should be reading this, what value is it to them? If I'm in the Great Lake States, if I'm in the Northeast U.S., I need to be planted on having DON and Zearalenone. I need to be proactive. I need to defend and protect my cows.
If I'm in Pennsylvania, Virginia, and North Carolina, I'm also going to be having fumonicin. And then my question becomes, do I use a single level of DTX or do I go to a double level? Because those are states that are going to have high DON, they're going to have high Zearalenone, medium for T2, but high fumonicin. So look at this, be it a producer or a nutritionist, I need to have a defend and protect strategy in place if I'm in those states.
Scott Zehr
You know, Larry, I ran into a case earlier this year where I was on a dairy and they had purchased quite a few acres of shelled corn from a neighbor. And it didn't really go well. It's not the neighbor's fault, right? It was, but we had very high toxin levels.
You know, when you're, one of the things that I look at when I see this toxin report is if I'm a dairyman or, you know, looking to purchase some corn from a neighbor, we might want to do some sampling if possible. But at least keep in mind that you're probably going to be getting some infected corn as well.
Dr. Larry Roth
Absolutely. So if I'm buying corn from a neighbor, I should probably be testing that. And if I'm in a mycotoxin prone area, again, the great lakes and the Northeast I should assume that I'm going to be bringing some mycotoxin in. And maybe I want to be buying corn from a feed mill that's doing some testing.
Scott Zehr
Well, exactly. Right. So You know, feed mills, they set some limits and, you know, they test that corn before it comes in their facility. And I think there's a conversation that might be another podcast down the road, but you know, when a load of corn at a feed mill gets rejected, oftentimes it ends up maybe at a different feed mill or perhaps at a producer's location as well, so.
Dr. Larry Roth
We're at the ethanol point.
Scott Zehr
The ethanol point.
Dr. Larry Roth
So we need to be concerned about feeding byproducts. And what could be coming in from a mycotoxin standpoint. If I'm taking corn and turning it into DDGs, well, I'm going to be concentrating the mycotoxin by a factor of three.
Scott Zehr
Yeah. That's a good point. So looking at again, the date range for these samples is March 1st to September 30th. Were our 2024 fresh corn silage samples included in these numbers?
Dr. Larry Roth
Yes, there was some 2024 corn silage samples that were included in these numbers. I would like to increase the number of fresh corn forage samples that we have to give us the opportunity for a better prediction of what we have coming up.
And Scott, that's a big emphasis that I've been trying to make is encouraging producers and nutritionists to sample the fresh corn forage as it's going into the bunker, into the drive over pile or the silo and being turned into corn silage. Number one, we ought to know what we have for nutritional value so we can plan for the coming year.
If we're a little bit low on starch, maybe we need to take a bigger position on corn grain. We need to know just where we're going to be nutrition wise. And then let's come in and let's evaluate from a mycotoxin standpoint. So we know that for this coming year, we have some contaminated feed. We need to put together a defend and protect strategy.
And let's remember with the fresh corn forage, we're probably going to be losing anywhere from 10 to 20 percent or more of dry matter during that fermentation process. How quickly do we drop the pH? How much do we get the oxygen packed out so we don't have wild yeast taking away nutrients?
So we could be significantly concentrating or increasing the mycotoxin value from fresh corn forage to the point of which it's being fed. So we just need to know going into the feeding year, what type of feed is it that we've got? And what is it that we can anticipate.
Scott Zehr
I'd like to encourage anybody out there listening, our email is [email protected]. Think Agrarian Solutions.com. agrsol.com. If you wanna get set up with us to, to do some forge sampling, you're more than welcome to. We take samples across the country. It's complimentary service that we offer.
But even thinking about next year most of the corn harvest in the U.S., is wrapped up now from a silage standpoint. Up here in the Northeast, I still see some, some corn that needs to be combined yet. But looking at that 2025 harvest you know. I pulled some of those fresh corn silage samples this year, Larry,
And it's not maybe as difficult to do as it sounds. I think one of the things to keep in mind if you're going out and you're going to chip you know, maybe hand cut 20, 30 stocks out of a field and chip it and take a sample, yeah, that's not a bad way to do it, but it's probably not what I would call a preferred way to do it.
Dr. Larry Roth
Yeah.
Scott Zehr
So, I think one of the thing to keep in mind when you're doing this, obviously safety we have, especially if it's like a drive over pile. You're going to be out there probably the same time as the pack tractors and the trucks. So please keep that in mind. But I've talked to producers too that have upright silos and it can be as simple as, hey, you're filling the silo today.
Have a five gallon pail next to your blower. And maybe take a couple handfuls from, or one handful from every wagon load of silage and blend that all together and that's what we'll sample. And it'll kind of give us a little more representative sample. Same thing goes with that drive over pile. We can pull multiple sites over multiple days if need be. Blend that together and try to figure that out. You know, Larry…
Dr. Larry Roth
A comment on that Scott, we've become purposeful.
Scott Zehr
Yeah.
Dr. Larry Roth
We've got a strategy how we're going to do that. And I just want a second, what you said about safety. But if we're purposeful, we know the pack tractor drivers are going to know that somebody is coming out there to get samples. And be careful for him.
So we're, we've got a strategy both from collecting the samples and a safety strategy as well. So that's an important point to keep Scott. Purposeful and safety is included in our strategy for getting these samples.
Scott Zehr
You know, one of the other things that I think about when I was pulling some of these samples this year, fresh silage, is there's like an auditing factor, right? So, you know, I can promise you most of these toxins are in the field. We're harvesting them. We're bringing them in. The levels are likely not going to go down once they're in storage. They very well could possibly go up.
But when we're sampling going in and we're kind of creating that baseline, when that pile is fermented and we go to feed it and we begin sampling it as we're feeding it, we're kind of able to audit our packing program.
Dr. Larry Roth
You bet.
Scott Zehr
Because if we see toxins that are growing in that feed that can grow in an oxygen rich environment. We know we have a problem there.
Dr. Larry Roth
Absolutely. It's just a way to audit, as you said, our entire program.
Scott Zehr
So Again, if you would like to get set up with us for that kind of a service [email protected] doesn't matter where you are in the country. I will make sure that that we make that happen for you.
Larry, there was another item I wanted to touch on and we don't see a lot of samples coming from the West coast. So for our West coast listeners, what would you like to encourage folks that are listening, maybe thinking California, Idaho, Washington Utah.
Dr. Larry Roth
You bet. Yeah, that's a good point. There's a lot of cows in those states. We should be doing some sampling there. At least going into storage to know what we've got. Take the state of California. There's a tremendous amount of byproducts spent. And there might be mycotoxins there, Scott, but they're not what I call the big five that we normally do our testing for.
The big five, aflatoxin, DON, zearalenone, T2, and fumonazine. They tend to be associated more with, shall we say, higher starch type feeds. Be it corn silage, sorghum silage, and the associated grains and byproducts. But we start thinking about vegetables that are fed, grape pomace, apple pomace.
Any place where we have microbial fermentation going on, we have the risks of molds growing, and who knows what type of mycotoxin they could be producing. So I encourage people, no matter what part of the country they're in, let's do a little bit of sampling. And then depending upon the feedstuffs and the weather pattern, we may want to go out a greater frequency of assaying to know the quality of our feedstuff or feedstuffs.
Scott Zehr
That's a great point. The food by products like you mentioned, the pomace and that kind of stuff. We ran into that a little bit in the Northeast with some apple pomace going in. And we were suspect of that apple pomace. The producer quit feeding it. Seemingly the problems went away. And then when they went back to feeding it, we sampled it. And been keeping track of that a little bit. And it does show up occasionally too. So good point on that.
Dr. Larry Roth
We associate patchelin with apple pomace. And again, there's how many different toxins can get produced in these different feedstuffs. And so we just need to be thinking about this. But let's have a strategy.
Scott Zehr
You mentioned the big five. So, obviously we're not really going to be thinking of maybe zearalenone, and DON, and aflatoxin in the pomace, like we'll go back to the apple pomace. But we're not just testing for those five toxins routinely, right? So how many total toxins are we testing for?
Dr. Larry Roth
I believe that we're testing consistently for 17 different mycotoxins.
Scott Zehr
Yeah, yeah. So, and again, if I understand it correctly, we're those 17 have shown to have some level of, impact on our dairy cattle and that's correct.
Dr. Larry Roth
Yeah. So some level of impact upon health production and reproduction.
Scott Zehr
Yeah. So feel confident if you are out on the West coast and you're listening and you, you're looking to do some sampling. We're not just going to sample for the big five. We're looking at multitude of toxins that could be impacting your cattle through the forage, your feed.
So Larry, as we wind down here a little bit I would encourage the listeners to reach out if need be for some sampling in the future, but also if you're interested in getting on our email list, you can do that by going to agrariansolutions.com.
You can also just email me [email protected]. And Larry, you know, what are maybe some three main takeaways that you'd want to pass along to our listeners today?
Dr. Larry Roth
You bet. Test your feeds, test your ration, so you know what the mycotoxin risks are. Test your corn silage, test your corn grain going into storage, so that you're able to predict what's going ahead.
Watch what your neighbors are doing. Watch what's going on in your area with all of the by products that are fed and the movement of cotton products and corn byproducts. We need to be cognizant of what's happening in our area and other parts of the United States.
Scott Zehr
I like it. Well, Dr. Roth, thank you again for putting the mycotoxin report together. When will we be coming out with our next report?
Dr. Larry Roth
Traditionally we come out with the next one in late March, early April.
Scott Zehr
All right. We'll be looking forward to bringing you back to talk about that. And real quickly, I want to make mention that we will be at some conferences this year. So if you're listening to this episode and you're going to be at the Cornell Nutrition Conference, October 22 to 24, be sure to come and say hi to myself, Scott Zehr, my colleague, Jeff Hostetter and Caroline Knobloch will also be there.
If you're at the National Angus Convention, November 1st to the 4th, make sure you say hi to Dan Hoying, our National Farm Program Manager. And November 6th and 7th, myself, Jeff and Caroline will also be at the Penn State Nutrition Workshop. And again, November 12th through the 14th at the Dairy Cattle Reproduction Council Annual Meeting.
So look forward to seeing everybody out at those conferences and again feel free to come say hi. If you have an idea that you would like us to discuss on Ruminate This bring it to me, I'll see if we can come up with something. Dr. Roth, again, I appreciate you taking the time out of your day today to go over the mycotoxin report. And we'll be talking with you again soon.
Dr. Larry Roth
All right. Thank you, Scott.
Scott Zehr
Thank you.
