53: Silage inoculants: what they do and don't do

Do forage inoculants really work, or are they just “insurance”?
Can they prevent or reduce mycotoxins in silage?

In this episode of Ruminate This, Agrarian Solutions’ Vice President of Nutrition, Dr. Larry Roth, explains the real role inoculants play in silage management. Tune in to learn  how the right inoculant can help preserve dry matter and nutrient value, why it can’t remove mycotoxins already present at harvest, and the practical steps to get the most from your forage.

Think of your silage bunk as a pile of valuable nutrients, the more protein and energy you keep after fermentation, the less you’ll need to purchase. From harvest timing to packing, covering, and inoculant selection, understand how to best protect feed value, reduce losses, and keep your herd performing at its best.

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Transcript

SPEAKER_01 0:01

Hello everyone, welcome to Ruminate This with Agraring Solutions. Join us as we explore ruminant nutrition and the impact of mycotoxins. Here we challenge your curiosity and explore new industry insights and research to optimize your herd's health and performance. Hey, welcome everybody to another episode of Ruminate This with the Grand Solutions. I'm once again your host, Scott Zare, and today also joined with our vice president of nutrition, Dr. Larry Roth. I want to make mention of something at the start of this, Larry. I was recently approached by a dairyman, and I think he was trying to calm me out a little bit. It was kind of a fun conversation, actually. But he looked at me and he said, Hey, and he's got his phone ready and he's showing me an article from a popular dairy press magazine that I'm not going to mention by name today. And he said, I thought you told me that inoculates, preservatives can't help control mycotoxins. And I thought about what he said for a second, and I said, Well, I think a lot of people think that we can reduce mycotoxins with a good inoculate preservative type product, which is not necessarily true in that term. We can't reduce what we bring in from the field. So I wanted to kind of bring you into this conversation today because surprisingly or not surprisingly, that still I think is thought by a lot of people that we can use a good inoculate or preservative and have less mycotoxins. You know, we've talked extensively on this platform in the past. Like, hey, what you bring in from the field is it's there, it can only go up. So I guess we're gonna ask you the big question right off the bat, Larry. Does putting an inoculant on our corn silage help in the realm of mycotoxins?

SPEAKER_00 2:22

Excellent question, Scott. Well, a good inoculant help control or limit mycotoxins, not necessarily. And I'm gonna say this from a couple of standpoints. We can have a very excellent fermentation, and when I define an excellent fermentation below pH, with corn silage below a pH of four, very quickly within say 24 to 48 hours, and in some of those best preserved corn silages, we can get rope 14 C. We can get petulin. Petulin, we typically see that more with apple type crops, but we can see it sometimes with corn silage. So I do not look at a well-preserved silage as necessarily lowering mycotoxins to come in from the field. I mean, really, the whole purpose of a silage fermentation is to preserve the nutrients that we have, principally sugar and starch to a degree, amino acids, and that if we can drop the pH very quickly, we limit yeast growth. And if yeast start to grow, they create heat, and we can create some heat damaged protein, acid detergent soluble crude protein. And so amino acids aren't as absorbed. But the biggest thing we're trying to do is drop the pH, stop the plant from breaking itself down so that we don't lose sugar and starch, which also shows up in reduced dry matter. And if we lose a lot of dry matter, and it may not be unreasonable to lose 10 to 25 percent of the dry matter, which means 10 to 25 percent of your sugar and starch, then you would have mycotoxins increased. We didn't get mycotoxin concentration would be increased. We didn't create any more, it's just that we have less dry matter to dilute out the mycotoxins.

SPEAKER_01 4:30

Okay, so I haven't been lying to people all these years by saying they're crazy to think they can reduce mycotoxins with an inoculant, is what you're telling me.

SPEAKER_00 4:39

Exactly. Good fermentation, the silage inoculants are not going to break down and metabolize the mycotoxins.

SPEAKER_01 4:51

Right.

SPEAKER_00 4:52

When the feed comes in from the field, that's the very best that you're gonna have in terms of quantity of nutrients and the very lowest mycotoxin concentration you're gonna have.

SPEAKER_01 5:08

Yes, yep. Okay, so you gave a kind of a description of the value of using a quality inoculate, right? But let's go a little further and talk about the different inoculation strategies that we see on different locations based on you know you bet.

SPEAKER_00 5:31

Okay, let's talk about different inoculation strategies. Again, the overall objective is to get as many nutrients out of the silage storage structure, be it a bunker, upright silo, what have you. So, number one, we ought to drop the pH as soon as we can because the plant's alive and it's gonna start breaking itself down unless we can drop the pH very quickly, and in essence, think of it as pickling the forage. So it's it's corn forage coming in from the field, it's corn silage after we go through the fermentation. Drop the pH. The other place where we can lose nutrients is yeast and mold growth, and this can happen during storage and it can happen at feed out. So one inoculation strategy might be to hinder the growth of molds, and that would take place with using like these bucrane and different acetic acid type bacteria, in that they specifically are producing factors that are going to limit the growth of yeast. Maybe not so much to mold, but if we drop the pH, we're typically going to stop yeast and molds from growing, more or less, more or less. So, strategy number one, produce a lot of lactic acid, drop the pH, pickle the forage so that the plant isn't breaking itself down, save the sugar, the starch. Second strategy limit yeast and mold growth so we don't get the heating where we get the heat damage protein we talked about earlier. Plus, we don't get the yeast growing at feed out and in the TMR where we can lose the sugar and starch because the yeast is growing. And anytime we pick up the corn silage or pick up the TMR and it's warmer than the environment, we've got yeast growing. And yeast growing means that sugar and starch that we wanted to go into the cow and make milk is now ending up being metabolized by the yeast and making carbon dioxide and heat. So hopefully not getting too deep microbiology-wise, but it's all about preservation, it's all about stopping undesirable practices.

SPEAKER_01 8:06

So I guess this reminds me of a of a story. I'm not going to tell the whole story, but I'll give the shortened version. And I'll preface this by saying like, we do not offer an inoculate product here at Agrarian. So, you know, what what we're sharing is experiences. And in Larry's case, you did spend a lot of time working on inoculates in your previous life. So working with bugs and bacteria. And I think I've shared this story with you. So the quick version of the story is a number of years ago, I was on a dairy that was hosting a silage management presentation, if you would, by a company that sells inoculates. The presenter asked the host dairyman a very simple question, and that was at what rate does he apply his product X? And the dairyman kindly stood up and said, if you put Forge up correctly, you don't need any of that, let's say crap. Now I felt bad for the presenter because he didn't know that the dairyman was a prospect instead of a client. But what do you say to guys like that? So, you know, I gotta believe there's some truth to that, isn't there? Of if we're putting it up correctly, we don't really need this because it's gonna ferment well. But then again, from your experience and in the years that you've worked on inoculates, maybe you have a different view of that.

SPEAKER_00 9:54

Fantastic. Great question. So, again, to be completely transparent and build upon what you said, Scott. I have spent part of my life in the inoculate world. And I would also be the first one to tell you that you can put up an excellent quality silage or halage without an inoculant. If you have good healthy plants, you do not have bad bacteria, you do not have high levels of mold and yeast, you do an excellent job of chopping, of packing, an excellent job of feed out, always keeping fresh feed in front of the cows. You do not need an inoculant in a perfect world. Unfortunately, Scott, we live in a fallen world and things aren't perfect. So let's go back to what is silage worth? It's worth more than what quite often we put a value on it. So let's just say, for the sake of argument, that we're gonna call a ton of corn silage $30,000, $35. It's probably worth more than that. We've got a bunker of 10,000 tons, which really isn't very much. That's $300,000 or more. Scott, if you had $300,000, would you leave it out in the rain? You'd probably put some plastic over it. Would you leave that $300,000 out there in the wind? You'd probably put a great big rock on it. So are we willing to put $300,000 or more at risk, assuming that everything is going to go perfect? And you know what the word assume is made out of. Okay. Yeah. So, yes, I would be the very first one to say if you get everything right, you don't need an inoculant. Unfortunately, how often is that going to happen? And are we going to run the risk? Are we going to gamble that we're going to get everything exactly right? How much are we willing to put that sugar and starch at risk? How much are we willing to risk that we won't have yeast growing and reducing the availability of the amino acids? That's the question. So I would agree with the gentleman, you bet you can put up excellent quality silage and alage without an inoculant. A few things go wrong, and we lose not sugar and starch, we don't lose protein, we lose dollar bills. That's the question. How much are we willing to risk?

SPEAKER_01 12:47

You know, part of this, and man, this is almost starting to sound like I'm not trying to sell anybody one way or the other, but you know, I've seen some of the data, right? Of dry matter loss, and there's all these economics that people put together with, you know, buy my silage inoculant. But listening to your description just now, there's like an inherent value there to ensuring you have a quality product put up. It's like you're broadening your risk range, right? Am I saying that correctly, Larry? It's you're giving yourself a little more leeway, I would say, with with your forward.

SPEAKER_00 13:24

Yep, yep.

SPEAKER_01 13:25

How many times have we said any morning when any dairy farmer anywhere in the world but wakes up, there's a thousand things that could be going wrong, right? And I almost see one of those benefits as having a little bit of a buffer to where things didn't happen quite right today. You know, it wasn't raining, but it rained during the night, and it was a little muddy around the pile, but not real muddy. Just little things.

SPEAKER_00 13:56

When do we decide to start chopping corn silage?

SPEAKER_01 14:01

Do we start when it's a little bit sometimes it's when the nutritionist tells us to?

SPEAKER_00 14:05

Okay, okay. So, do we start when it's a little bit wet so that by the time we're done, it's not too dry. So the more water we have in the silage, because we started chopping a little bit wetter, the more lactic acid we need produced to drop the pH. That would be a good situation to use on an oculant. And then boy, we had great chopping weather. It was what 80 degrees, the wind was blowing. Uh, we didn't have any weather breaks during the course of the week, but those plants sure dried down. And as they dried down, we lost that moisture and we lost some sugar. We lost some sugar, so now it's going to be harder to drop that pH. Yeah, we got to have it happening really quick, getting the lactic acid produced. We need the inoculant. Or the other scenario, we start chopping and we get some weather breaks. Are we doing something to keep those yeast and molds from growing? We need to be doing that. So we can lay out all kinds of scenarios and we could have excellent chopping conditions, but maybe face management at feed out isn't the best. Maybe we feed our cows only one time a day, and so are we doing something to limit the yeast growing in the corn silage so that our feed doesn't heat up so much? So there's so many different scenarios. I guess I would come back and say, Scott, tell me the challenges that we need to manage for, and then let's put together a program. So inoculants are not a cure all, they're not going to solve everything, but they're just another tool in the toolbox to be used along with everything else. So, yes, you can absolutely put up excellent quality silage and halage without an inoculant. No, inoculants are not cure alls, they're not that magic bullet, but they're just another management tool.

SPEAKER_01 16:14

So you've mentioned lactic acid products, you've mentioned acetic acid products. I don't know which one I want to use.

SPEAKER_00 16:21

Okay, tell me what is our biggest challenge? You know, we've got pretty good quality corn silage, a lot of sugar, a lot of starch. We've got excellent face management. We feed our cows two to three times a day. We're always keeping fresh feed in front. We do an excellent job of face management on our bunker. Let's go for that lactic acid inoculant. Let's drop the pH as soon as we can. So we save as much sugar, starch, dry matter as what we can. You know, sometimes those corn plants dry down too fast. Our face management just isn't what it ought to be due to labor situations. As happens on many dairies, we're only going to feed one time a day. Then maybe we should think about some of these acetic acid type inoculants or propriontic type acid inoculants, and limit the yeast and the moles from growing. Tell me what are the biggest challenges that we face, and then we'll pull the right tool out of the toolbox.

SPEAKER_01 17:25

So, you know, I've growing up on the dairy, dad would always put inoculate on, and you know, small farm, upright silo. I would say we weren't really in the position where we had to really keep track of dry matter tons on a basis of like, are we gonna have enough feed to feed the cows? I mean, we had plenty of feed for our land base for our cows, but there was always the question though, in dad's mind, is this really working? And you know, I think there's a lot of research to say that it it's probably a good idea to do this. But taking out the is it working or is it not working? Question, is there a range in between those two of effectiveness? Like, can we apply this? And it's maybe not as effective as what we thought it was gonna be. And what are the factors around that?

SPEAKER_00 18:23

Okay, is your question is there a range of effectiveness of the inoculants?

SPEAKER_01 18:28

Yeah, is there are there limiting factors of how effective an inoculant can be? I guess is maybe a better way of saying that.

SPEAKER_00 18:34

All right, great. First, we got to get the bacteria onto the crop, we got to do that. So we need to have the right nozzles, we need to have the right application rate, and sometimes adjusting our applicator, be it mounted on the chopper or be it stationary mounted at the blower for the upright silo that you were talking about. Sometimes that is one of the biggest things that we need to look at. And you look at some of these low volume applicators today. Oh my goodness, we're hardly putting on any volume of inoculant per ton. And then we become dependent upon turbulence and mixing to help it all get mixed throughout. The other thing that, and I think it's something that so often people ignore the bacteria, once they're hydrated, they're living organisms. Before they're hydrated, they're like the battery on your car or your truck. You leave the lights on the night before, it's going to drain the battery. You go to start your car or truck the next morning, and you hear. Hopefully, you you at least hear that. Might not hear anything. So the bacteria are dormant until they're hydrated, but they could still be losing their energy because we haven't handled them properly. Ideally, we're keeping them in the freezer or at least in cool conditions so they don't use up their energy reserve, so that once they're hydrated, they're ready to go to work. Then, once we have these organisms hydrated, they're going through metabolism. Does our inoculant have sugar in it to serve as a food or energy source for the bacteria to keep them alive so that once they're sprayed onto the forage, they're ready to go to work. Then sometimes when we're chopping it, it gets kind of warm. And you look at certain choppers, and there's a certain brand of chopper that I won't mention, but costs a tremendous amount of money, extremely good engineering, except they put the applicator tank right under the engine. And if our inoculant solution gets warm, by that I mean oh, probably 80, 80 to 5 degrees Fahrenheit or warmer, these bacteria are using up their energy. They're going to expend themselves and not be ready to go to work when it's rayed onto the forage. So simply taking a frozen pot bottle and putting that into the tank to help keep the temperature down can go a long way toward increasing the success of the inoculant. Don't put ice in there because that's going to dilute our inoculant solution, but just put that frozen bottle of water of ice in there to help keep the temperature down. So I would say the some of the biggest factors related to inoculant effectiveness, application thoroughness and correctness, and having live bacteria to apply.

SPEAKER_01 21:43

Yeah. You know, going back to kind of the the start of this episode, Larry, thinking about the mycotoxin side of this conversation. I guess just kind of wrap us up in a in a bow, if you would. We have Established, right? Especially with Don and Xerolinone, two of the toxins we see the most of in some parts of the country this year from Onesin. Like what we harvest is what we have. As you said, as we have a lot of dry matter shrink, we could actually see higher concentration levels, which yes, is going to show up as a higher number on the assay for sure. But just to reiterate, those field-borne toxins, like Don Xerolinone, Femonosin T2, there's no inoculant out there that's going to drop that number.

SPEAKER_00 22:38

Correct. Correct. There's no inoculant that's going to break down the mycotoxins.

SPEAKER_01 22:46

So where we really get into this discussion, to where the gentleman that I referenced in the beginning, the dairyman that showed me the article from Popular Press, is the storage-borne toxins.

unknown 22:59

Okay.

SPEAKER_01 23:00

So I'm just thinking of it like that way, right? So, you know, I think one of the things you first told me when we started seeing rope fertine C come up, albeit folks, I know we're dropping maybe a toxin that some of you guys have never heard of today. And Larry and I have discussed rope fertine C in the past. Uh, the fun fact about rope for C rope fertine is that if you've ever eaten blue cheese, you've probably had rope fertine. Yeah. Or you have had. However, uh, that is a toxin that typically shows up in actually really well preserved corn silage piles. Yeah. Right? We maybe didn't pick it up in the field, but it shows up in storage. Yes. Now, just the opposite can happen where we can have maybe poor fermentation or air pockets, and we can have molds that proliferate and make some mycotoxins in storage. Or a good inoculate that maybe helps with the fermentation will potentially limit some of those factors. Is that fair to say?

SPEAKER_00 24:08

Potentially so, yes. So let's think about what causes a mold to make mycotoxins. Number one, the mold gets stressed. Might be that it's not growing, and that could be a situation where it's deprived of oxygen because we did an excellent job of packing. Might be temperature, it's too hot. Sometimes we're chopping corn salads when it's above 100 degrees Fahrenheit. We might get some humonosin if those molds get stressed. Sometimes when it's really cool, we're 35, 40 degrees. We might be getting some of the dawn being created actually during storage. The rope protein C you reference seems to get on ironically produced when we have some of our very best silage fermentation conditions. Very low pH, high lactic acid, everything looks fantastic except dogonic, we got some of that rope protein seed. And what's interesting, Scott, is with all of the mycotoxin assays that we look at, we just really do not see much rope for teen seed. And so I'm going to attribute that back to if we can improve plant health generally, we have fewer moles. And that may be one of the biggest things. What can we do out in the field to improve plant health so that we have fewer moles out there? They're less likely to get stressed if they're not present, and so less likely to make the mycotoxins, and then once we come into storage, drop the pH in a hurry. But again, we can get rope protein C under some of the very best conditions.

SPEAKER_01 25:59

I didn't do a hard count, but to back your point up, I know I said this. I mean, you and I talked about this beforehand. Maybe two percent of the samples. Yeah, uh, I'd be maybe maybe five.

SPEAKER_00 26:17

I would say five would be at the very upper end.

SPEAKER_01 26:21

Yeah, it's not much. So, you know, we test for rotene C and mycophenolic acid, patulin, citrine, and all these kind of underlying toxins because there, yes, folks, there is research saying that they can have negative effects on your cattle. I think the reason they don't get talked about much though, Larry, is because we see them maybe five percent of the time. I don't, yeah, I don't remember the last time I saw a sample with citrine, and it's probably been years. I bet it's been three years, four years. Yeah, it's been a long time. So, you know, I don't I don't want to scare anybody today. Like what we're talking about as far as the roque fritine goes and some of these other, I'm gonna say lesser known toxins, it's a very small percentage and it doesn't come around very often. So I I wouldn't I wouldn't go out there if you've never used an inoculant, I wouldn't go out there today to purchase an inoculant with the goal of having less patulin and roque fertine C in your corn silage is probably not worth it.

SPEAKER_00 27:26

Let's go out there, let's do the very best job we can with our silage and halage, our high moisture corn, any of our fermented feeds. I think in many situations, and again, we don't sell inoculants here at Agrarian Solutions, but I think that in most situations, a high-quality inoculant, note how I described it, high-quality inoculant is going to help you have greater preservation of nutrients. And then let's let the chips fall where they may with things like mycophenolic, rope protein C. And oh, by the way, Scott, we have the DTX concentrate that does an excellent job of defending and protecting against a wide range of mycotoxins. So, yeah, do the very best we can with our stored feeds, and then let's employ the DTX concentrate to defend and protect.

SPEAKER_01 28:20

Awesome. Well, Larry, you know, I I appreciate you jumping on this call today and uh kind of walking us through that. I know you and I discussed this article uh at length a little bit, and I think it was some good fodder, but also it was it was good to I think have this conversation from the standpoint of you know what's taking your experience in the inoculant uh side of things, what's the truth, what's not the truth? And Larry, I'm still gonna stand by whenever somebody asks me if an inoculant's gonna decrease their mycotoxins, I'm still gonna tell them no. You haven't changed my mind otherwise.

SPEAKER_00 28:58

Yeah, it's not it's not gonna decrease it. Yes, it may help to limit the growth in the storage structure, but it's not going to break down the mycotoxin. You're correct.

SPEAKER_01 29:10

There you go. You heard it here, folks. All right, Dr. Roth, I appreciate your time today. Thanks for jumping on another episode of Ruminate This with me, and we'll be talking to everybody again in a couple weeks.

SPEAKER_00 29:19

All right, thank you, Scott.

SPEAKER_01 29:22

Thank you for listening to Ruminate This with Agrarian Solutions. Look for our next episode in two weeks.