The Moos Room™

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Emily: Welcome everybody to The Moos Room, OG3 here. Little bit exciting. We have the gruesome twosome in person, and then we have Bradley on the other line. Hi, Bradley.
Bradley: Hello.
Emily: Are you a little sad you're not in person with us today?
Bradley: I am. I'm jealous that you two are together in the same room today and I'm just here at home still.
Emily: As we've said several times, it's been so long since all three of us have recorded in the same room.
Joe: Yes, it's been, I think episode one, maybe two-
Bradley: Exactly.
Joe: - maybe three.
Emily: Oh my God.
Joe: 70 episodes ago we were in the same place.
Emily: Yes, and now two of us are together and Bradley will be with us soon as well. This week we're going to be talking about something related to, of course, the thing on everybody's mind, the drought that we are seeing. I know that a lot of people, my family, people I just talk to, friends and stuff, whenever it rains, they always get so happy because they're like, "Oh, well, it's raining so everything's green again. That must be good for the farmers, right?" Joe is shaking his head, he's like, "No, no."
Joe: No.
Emily: What we're talking about today and specifically why everything greening up right after rain should be an area of concern for cattle producers is nitrate poisoning. I don't know, maybe I'll throw it over to Dr. Joe to give like 30 second, what nitrate poisoning is and then we can get more into it.
Joe: I think the biggest thing to know, it comes from one of our colleagues, Troy Salzer. The goal whenever we talk about nitrate poisoning according to him, is to scare everyone because you should be scared of it. It's scary. You can kill cattle quick and there's not a whole lot you can do about it after they eat whatever they're eating that has all those nitrates in it.
Nitrate is just something that accumulates in plants, cattle eat it, it causes a lot of problems by converting to nitrate, which can't be converted away from nitrate fast enough and that binds with hemoglobin to create methemoglobin, which doesn't carry oxygen.
What happens is these cattle basically suffocate. They have no oxygen being delivered to the tissues in their body, and they die from lack of oxygen, which is a horrible way to go. It's a real deal. This is a real thing that's happening in Minnesota. We've already lost cattle to it. Everyone should be aware and they should be scared of it.
Emily: I mean I know I'm already scared because what we're basically saying is these cattle asphyxiate to death.
Joe: Yes, 100%. It's just a lack of oxygen being delivered to everywhere in the body that needs it, and then they're gone.
Bradley: It's really quick. This is not a, oh, it'll happen a day later or overnight or it's very quick, very quick.
Emily: What is it? Hours?
Joe: Yes. As soon as half-hour up, four hours. It's happening pretty quick. Low level's going to be a problem too for other reasons, but what we're really talking about today is just cattle actually dying from this and having a problem because of that nitrate going to nitrate, then binding the hemoglobin. It's just a bad situation and that all happens really quickly.
Emily: All right. Let's briefly talk a little bit more about the process of why we're seeing this increased nitrate in the plants. Again, we're in drought conditions, right after we see rain, everything turns green. Joe, I'll let you take it from there.
Joe: Well, and maybe Bradley's better at this since he's the grazing expert and all this, but from my understanding is that basically what happens is that in a normal year, plants are growing, everything's fine because they're absorbing nitrate and that's getting converted pretty quickly to amino acids and protein to allow that plant to grow. What happens is, plants need water, sunlight, and the right temperature to grow and if you disrupt any one of those three things, you end up with the plants still absorbing nitrate but not growing.
The roots are still absorbing all that nitrate and storing it in the base of the plant, in the stem, and some of the lower leaves and the roots as well. It sits there and accumulates and continues to accumulate so that when that plant does grow, there's a lot more nitrate there than there would be normally. Does that seem about right, Bradley?
Bradley: That's correct. Joe's all thrilled that I gave him a A plus for the--
Joe: Got a non-animal thing right.
Bradley: Right.
Emily: Right. We're so proud.
Bradley: It happens really fast in lots of different situations, whether it be drought. We talk about it a lot in drought situations, but it doesn't necessarily have to happen in a drought situation either. You can see it in many different factors. If you're growing grasses or forages with a lot of manure buildup on them, it can happen. It's very concerning in a drought situation, but you always have to be thinking about it as well.
Emily: Joe, cut this out if I'm wrong, so I don't sound stupid on the podcast, but in a "normal year", don't we usually see it a little more in the fall sometimes? Am I still making that up?
Joe: I think you're right. You're right. We do see it in the fall because of the small grain aspect to it. That's part of what we see and that has to do with what Bradley's talking about when we get these other situations where it's a different temperature, a lack of sunlight or like this year, a lack of water. Fertilizer has a big piece of this and it doesn't really matter what kind of fertilizer, manure, or whatever else you're putting on there.
When you get some of this regrowth from small grains after they've been harvested, things like that we do see it traditionally in the fall. It is an issue every year, but specifically this year it's more of an issue.
Emily: It's an issue, we've established that, related to drought, can happen any time though. I think next I want to go to, if I'm a producer, how do I know if I am having this problem? How do I know to be on the lookout for nitrate poisoning? We're waiting for the grazing expert to respond.
Bradley: You're waiting for me. I think one thing to think about is you have to think about it from a grass species standpoint. We usually see this in warm-season grasses a lot more. We talked about when we can see it during the year. Well, you see it a lot in warm-season grasses or some sorghum Sudan grasses, Sudan grass during the summertime and you can see it in oats or whatever you're grazing in the fall.
One thing that we've also seen with our grazing cows is if you get into a field or a pasture that has a little bit of pigweed in it, maybe a little more pigweed than what you notice, you will get some accumulation of nitrogen from that. There's lots of different species. I think most people think about nitrate poisoning from warm-season grasses only but that is not necessarily true. There's a lot of different grass species that we can see.
What do you do about it? You should probably test for it. Whether it's a pasture or you've made silage. We've made sorghum Sudan grass silage before. You always want to send it to a nutrition lab or a forage testing lab and test for nitrogen levels. It's cheap, less than $25 to do that and it'll give you a nice output, a range of what your nitrate nitrogen levels are in that forage.
Joe: Is it true Bradley, because I truly don't know. Does ensiling actually sometimes help decrease the level of nitrate when you ferment or try to store that feed?
Bradley: Across time, yes. The longer time that it's ensiled, yes, you do see some decrease, but you should still test for it even though it has been ensiled. Yes, if you ensile it for a short period of time, it's going to be higher than if you let it go for another year. I'd recommend if you're making sorghum Sudan grass silage, you probably should wait a few months before you even go into it because of the accumulation of nitrogen right away in that plant.
Emily: It really seems like testing is the way to go to know what your status is with it, what's going on in your pastures with it. Besides that, what are some symptoms we might see? We've already scared everybody with the whole your cows are going to drop dead in an hour, but if they can catch them before they drop dead in an hour, what sort of symptoms might people see or if there's a lower level of nitrate poisoning in cattle?
Bradley: Well, since it's due to lack of oxygen, you're mostly going to see heavy breathing from the mouth. You're going to see lots of respiratory movements really are the issue. If an animal is heavy breathing or obviously if they're not breathing, that's not a good sign either but it's really going to have to do with respiratory distress.
Joe: Not breathing's a good sign that you got a problem. The other thing I like to check, if you're super worried about this and you're turning cattle out for a half day or something like Bradley's doing now, I bring a few animals in and I check mucus membranes. That's going to be the first thing you see when we get to methemoglobin levels at 20% or so. You'll start to see gray, blue membrane in the gums, under the lip, inside the vulva, they'll turn from a nice bright pink color to a grayish or blue color. That's the very first thing you'll see. Because by the time you get to panting, you're in--
Emily: You're in the death zone.
Joe: Yes. You're getting close to just not being able to do anything about it. The other thing that I always think about with this too is that it's additive with any other source. If you have high nitrates in your water-
Emily: It's cumulative.
Joe: -it's cumulative. That's the word, cumulative. Good thing, Emily's here in the same room.
Emily: Got you, babe.
Joe: [laughs]
Emily: Gruesome twosome.
Joe: Gruesome twosome. It adds up. That's another thing to check. If you have the ability to, or if you're worried about it at all, I like to check everything, if you can. Now, that's not always possible. The most important thing to check is whatever the cattle are eating.
Bradley: If you have sensors in your cows-- Oh yes, I'm going to put sensor in it.
Emily: Did you say sensors, Bradley?
Bradley: Yes, I did. You can put a sensor in it. We've seen that before in our cows. Granted it takes an hour or two to actually see that, but we've noticed it from our sensors. You can see rumination just drops off significantly if there's a problem with nitrates. They have gigantic belly aches, for lack of a better word. What are some other things that we might be able to do?
Joe: Cattle can get used to nitrates too. They can build a tolerance to the nitrate in the diet, but they have to get used to it and it has to be very gradual process. Again, you think about just an animal in a feedlot. You start them small and little bit of grain and you build them. That's the same thing you do with nitrates. Now, I'm going to advocate that you work with a nutritionist to do that. That's not something you should be playing around with because like we've talked about, it's scary, it's dangerous, so you need to be working with someone who knows what they're doing.
Emily: Mark it down. The vet suggesting you use your nutritionist. This is a big day.
Joe: Big day. Contrary to what a lot of people think, I do like nutritionists and I try not to butt heads with them too often. There's things that we will butt heads about, but you do need to work with a nutritionist on this. There's no way around that at all.
Bradley: One thing that we've done that has maybe helped and could be recommended is if you're grazing maybe some forages, warm season grasses is to not do it in the morning so you graze into the afternoon or to the evening because nitrate levels tend to be higher in forages in the morning. You can graze later in the afternoon or it's not much of a problem if you give them something else to eat. If there's hay or TMR or something else, before they go out and consume either silage from these forages or graze, you can do much better by having some fill in their room instead of going out there on an empty room.
Joe: That helps a lot, taking them out with an already some fill in that room and so they don't gorge themselves right out of the gate. That can definitely help you get through some of those high nitrate feeds that you got. I think we pretty much said this, but we need to reiterate. This year is weird and this is a different year. We're talking about pastures being an issue that traditionally would not have been an issue, talking about anything you harvest, regrowth on anything.
This is a problem for pretty much any feedstuff right now. Don't be thinking that you need to just test your summer annuals or your oats or any other small grain you need to test. We're talking pretty much anything at this point that the cattle are going to eat, you should be testing. That probably brings us to sampling. Taking the right sample is super important in this. Bradley, can you help us figure out how we're supposed to sample a pasture?
Bradley: If you have a pasture, you're probably going to want to take-- We're usually doing five to six places where you harvest the forage and then you mix them all together to make sure that you get a representative sample of that pasture because cows are going to go all over the place. You want to get an idea of what they're going to eat across the whole pasture. That's one thing that I would recommend is make sure you take enough forage and you mix it all together before you send it into the lab.
We would do that with, if we had say sorghum Sudan grass silage, we would take it from many different places in the bag or bunker or wherever to get more representative sample.
Joe: The easiest way to think about it for me is what are the cows going to eat? If you're going to let them graze that pasture all the way down to almost nothing, you need to take the whole plant. If you're really going to think about letting them in there and only graze the top half, you just need to take exactly what the cows are going to eat and really think that through because if you take the wrong sample, it can be dangerous because you don't know what you're actually dealing with and what those cows are actually eating.
Emily: I also suggest, and you were getting at this, Bradley, that you want to take five, six samples from a pasture and make sure that if your pasture has some different terrain in it, you have a hill on there, making sure you're getting things at the base of the hill and on the top and in the middle just to make sure that again, you're getting really representative sample because we know that those areas that are hilly, especially the soil can be vastly different from one spot to another. That plays a big role in it too.
Bradley: The biggest thing to remember is you should test the forages. I don't know if we can reiterate that enough. You should test it. That is your insurance policy to making sure there's not a problem. One thing is what happens if you do have a lot of nitrates? Then what do you do? Now what do you do? That's a good question. I don't know what to tell you there.
That's a idea of if you have one sample that you sent in, maybe you wait a week and re-sample it again to make sure that the numbers are correct. Or you can blend in, if you have a TMR, blend in some of that forage is a small amount.
There's ways to get around it because it does happen where you have nitrate levels and they're at that limit and it's like, "Now, what do I do because I have all this forage and now I can't feed it?" That's not really true either.
Joe: Diluting I think is probably the most popular way to work with this, but not everyone has that capability either. This is where you need to really lean on your neighbors and find someone who does have that ability and figure out what you can do with that feed or pasture because it can be challenging once you have high nitrates. Important to get the cows off of it first and then figure out what to do working with your nutritionist.
I think we've covered a lot. There's all sorts of more stuff we could talk about. We could get deeper into the plant biology side of things, but honestly, I don't think we have the right people here to do that. We shouldn't.
Emily: We know some of you listen to us in the tractor. We don't want to put anyone asleep.
Joe: Agreed.
Emily: All right. We are going to wrap that episode there. If you have questions, comments, scathing rebuttals, you can email those to themoosroom@umn.edu.
Bradley: That's T-H-E-M-O-O-S-R-O-O-M.
Emily: @umn.edu. Good job, Bradley. You can find us on Twitter @UMNmoosroom and @UMNFarmSafety. Visit our website extension.umn.edu for more information on a lot of things related to the drought and cattle production in general. Plugs are done. We are going to let you go on your merry way. Bye.
Bradley: Bye. Jersey's the correct answer.
Joe: Yes.
Emily: Gruesome twosome. [laughs]
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