Help Your Cattle Avoid Heat Stress

The Midwest is definitely feeling the heat, prompting extra concern about heat stress and dehydration. Allison VanDerWal, a nutritional Formulation Specialist with Form-A-Feed, talks about these issues and what cattle producers can do to minimize risk.

Transcript

SPEAKER_01 0:25

Welcome back to the Sunation Podcast, where we explore the story, science, and challenges shaping the livestock industry today. I'm your host, Jill Funky. Joining us today is Alison Vanderwall, nutrition formulation specialist with Formafeed. Thanks for being here and joining us. Thank you for having me. It's an honor. So as we move into warmer weather, really looking at heat stress and dehydration, and they're a major concern for both cattle and calves. And so this isn't just a comfort issue. It directly affects intake, growth, immune function, and really overall performance. So today we're going to break down the different levels of heat stress severity, what's happening inside the animal at each stage from a metabolic standpoint, and practical ways producers can prevent those losses. We'll also talk about strategies to maintain hydration, including tools like water additives designed to encourage intake. So let's get into it. To start us off, why is heat stress such a significant issue in both the beef and dairy cattle, especially in those little calves?

SPEAKER_00 1:30

Yeah, it's um it's a huge issue because when we talk about dehydration and heat stress, first of all, dehydration and water intake is directly correlated with total dietary intake. If we reduce that, we reduce dietary intake and we want animals to feed so that they can reproduce and grow and and make money and produce for us.

SPEAKER_01 1:48

Alison, what are some early signs producers should be watching for before heat stress really becomes severe?

SPEAKER_00 1:54

Yeah, I think that's a great question because I the first thing that I would encourage people to look at, we all love looking at the weather. We grew up if you're in the farming community. I mean, the weather apps probably are stand out in the weather too. Absolutely. Absolutely. We're obsessed with it. So that is going to be your biggest factor. If you start looking at the weather in the THI index, that temperature humidity index, when we start adding that humidity plus the temperature that they're supposed to be having, that's when we can start really taking preventative action.

SPEAKER_01 2:21

And isn't like isn't anything over somewhere around 70 degrees, you know, when when that can start for cattle? Yeah. Yep.

SPEAKER_00 2:29

That THI I believe it's about like that 75 range. And that's really good. I'm glad you brought that up. Is we'll walk outside and be like, oh, it's a gorgeous day. I'm not experiencing heat stress. Cattle experience heat stress. And we're talking heat, not just cold stress. They experience that at different temperatures than you and I. So when we're comfortable, they might be getting a little too warm.

SPEAKER_01 2:49

So let's walk through the different stages of heat stress. So we're going to start with mild heat stress. And so what are the first physiological changes happening in that animal?

SPEAKER_00 2:58

Yeah. So from a physiological standpoint, um, we're probably gonna notice that cattle are gonna start reducing their intakes. You might see them seeking out shade if they're cattle on pasture or even in a in a feed yard, if you have a shade type thing, they're gonna start gravitating towards that and and maybe hanging around that water fountain a little bit more. Um, but you're probably gonna see it in the feed bunk, feed bunk first. They're gonna start backing off on intake.

SPEAKER_01 3:19

So then if we move into moderate heat stress, you know what's happening metabolically inside the animal.

SPEAKER_00 3:26

So as they start reducing that heat stress, you're gonna see an increase in panting, respiration rate's gonna increase, and that's gonna happen in mild as well. But as we increase that severity, respiration rate's gonna increase. They're actually gonna start salivating more. That probably gets a little worse when we get to more of that severe. But then they're gonna be starting to expire more. There's gonna be more expression of CO2, there's less buffering capacity, we're changing the pH within their body. So we're kind of changing on a metabolical standpoint, they're redirecting blood flow to the extremities, they're increasing sweating. There's kind of a lot that's happening there that's really changing the normal body function to something that's actually requiring a little bit more energy for that animal to dissipate heat and really cool itself off.

SPEAKER_01 4:08

And you mentioned pH. So how does increased uh respiration begin to alter blood pH and the electrolyte balance?

SPEAKER_00 4:16

Yeah. So as that animal starts panting, try to relieve some of that heat off of them, they're expelling a lot of CO2. They're also starting to sweat, so their blood flow is getting redirected to their extremities, so it's going from the rumen and their viscera organs out to try to dissipate heat to their extremities. Uh, they're starting to sweat more, and and electrolytes are really just charged molecules, think salt, potassium, magnesium, sodium. They help water movement. So when you're sweating, you're expelling those because the water's drawn out to those cells. So we need to repopulate those electrolytes. That's why if you see athletes, livestock's kind of athletes too, are putting them through a lot. They need to hydrate so that they can either raise that calf, they can they can put pounds of gain on, and and so on.

SPEAKER_01 4:59

And because that energy is being redirected, so it's not going to be for digestion. Yeah. Because that's not as important right at that moment. And so then is that why they don't feel as hungry?

SPEAKER_00 5:09

It's a little bit. Um, if you think about the rumen, I mean that is just a massive fermentation fat. So that creates a lot of heat. So they're kind of redoing it. There's some research. I think Dr. Baumgard's lab in Iowa State has done a lot of that research to say, are they not eating because of the heat production? Are they not eating because of the heat stress that's actually causing it?

SPEAKER_01 5:28

So you mentioned rumen. Anything else you want to say about the function and nutrient utilization?

SPEAKER_00 5:34

Yeah. So with a heat-stressed animal, um, we just talked about um increasing respiration rate and decreasing nutrient intake. Maintenance requirements actually go up. That animal's trying to actively cool itself down metabolically, but intakes are going down, which means nutrients are going down. So they're metabolically, the Dr. Baumgard calls a heat-stressed animal like in a metabolically challenged state. And so they're they're not really mobilizing fat to help. They're they're kind of taking away some energy from our muscle tissue. We're we're losing some of that rumination and fermentation capacity because they're not eating. So it gets to be really challenging.

SPEAKER_01 6:12

And so then let's go to when an animal is in severe heat stress. What are the critical metabolic breakdowns that are occurring?

SPEAKER_00 6:21

Yeah, I feel like the ones that we've we've covered, it's just getting exponential at that point. I mean, they're really not eating. Like I said, their energy they're taking, they're not mobilizing lipid, which we typically associate like with an animal that's in an energy deficient state. They're going to mobilize their fat tissue to give itself energy. Dr. Baumgard's lab has found out they're not actually doing that. There's so it's actually changing the composition of gain. They found that out. Instead of putting energy towards muscle gain, sometimes it's putting it more towards lipid initially. So it's it's completely changing what our normal thought processes of a normal animal and how it's growing, or even on the milk production side as well. So there's, yeah, there's some major changes that are happening to this animal. I mean, there's a lot of research that's focused with it. It's an extremely complex metabolical kind of conundrum that the animal's going through. And you and I, I mean, when we're when you're rock picking in the summer, we're baling hay. That's a big metabolic stressor on us because we're just trying to dissipate that heat.

SPEAKER_01 7:17

And it's like maybe a cascading failure, too.

SPEAKER_00 7:19

Absolutely.

SPEAKER_01 7:20

One system is affecting another, and then that affects this, and then it circles around right. For sure.

SPEAKER_00 7:25

You're panting, you're changing the blood flow, which affects GI, they're expelling saliva, that affects GI. It's it's yeah, there's a lot of things going on.

SPEAKER_01 7:33

Let's look at dehydration. So, what's happening with dehydration, including the reduced blood volume and the animal's ability to regulate their own body temperature.

SPEAKER_00 7:44

If you think about heat transfer, like you think about cooking, you have like convection, radiation, conduction. The animal can only dissipate heat in so many ways. When it is super hot outside and the air temperature is just as warm as that animal, there's no way to convect. So, sweating for them to try to dissipate heat that way, that's also why we encourage some air movement. So when they sweat, that breeze kind of goes across their back and it helps take away some heat from the body that way. When they start getting dehydrated, we're taking away that sweating ability. We've all been told, um, even as humans, if you stop sweating and you're outside, you have a serious problem going on. It's the same in the animal industry. We need to make sure that that animal keeps sweating. We need to make sure they drink water, that we're repopulating them with electrolytes so that they can dissipate heat since it's a little harder with the heat index that they're dealing with.

SPEAKER_01 8:34

Then at what point is this life-threatening? What are the warning signs that we're just we shouldn't ignore?

SPEAKER_00 8:40

Yeah, I mean, if you see that animal deep panting, heads out, lethargic, I mean we've all kind of seen those warning signs in that animal. We try to make sure that we don't get to that point. Um, but if you do, don't stress that animal. I know we always talk about animal handling, but try to seek shade, get that animal cooled off, try not to shock that animal.

SPEAKER_01 8:58

Okay. So we mentioned dehydration a second ago, but I want to look at that again and how closely tied are heat stress and dehydration in cattle and calves?

SPEAKER_00 9:06

Yeah, they're they're linked. When you have a heat stress event, again, you're you're increasing that sweating dehydration is coming with it because you're just trying to put out so much sweat to cool yourself down. So we really need to make sure that that animal is rehydrated. On the calf side, if we're thinking about like calves on milk, whether you're a dairy producer or a calf raiser, it's a little more severe because if we think about it, um, I know Penn State's done some work on this, that animals diet is basically liquid, it's milk. So they can get dehydrated um easier, they can scour a lot easier, and we can have a little bit more issues with them.

SPEAKER_01 9:38

So when we look at all of these stress levels, Alison, what are the biggest impacts on performance that producers should expect to see?

SPEAKER_00 9:47

Uh from a beef cattle standpoint, specifically in a feed yard, that's where my mind always goes. When we're reducing intake, we're we're hindering growth. I mean, we need the calories for that animal to gain. So we can expect reduced feed intake, therefore a decrease in in gain, uh poor um feed conversion, and an increased cost of gain. So basically everything is going in the wrong direction when we're looking at a balance sheet. On the dairy side, you're looking at less intake, means less milk production. We can be herding some of your components on a reproduction standpoint. When that animal gets, and this is dairy too and beef, or really any species, when you're breeding them, um, we want to make sure that that body temperature of that animal is not getting too high. I believe the cutoff is like 103, where if that animal body temperature gets too high, you can have some embryotic death with that. So we want to make sure that that animal's staying cool when it's just bred so that we maintain that pregnancy.

SPEAKER_01 10:37

Perfect. And what about any immune response and disease risk?

SPEAKER_00 10:41

Yeah, excellent question. The immune system is a big energy demand. It takes a lot of energy to run an immune system. And when an animal's stressed, you were weakening that immune system or making that animal more prone to illness. We're already setting it up. If it's decreasing intake, it doesn't have enough nutrients to even help fuel that immune system. It's kind of this cascading effect. Um, it it just brings in a lot of issues. You see, if you have any chronics on a farm that they kind of flare there, they're gonna they might have that issue of a secondary illness. Things can just kind of unravel snowball effect. Yeah.

SPEAKER_01 11:17

And so can some of these impacts um linger even after we're back in a cool temp?

SPEAKER_00 11:24

Mm-hmm. Yeah, I uh the recovery process after a heat event, um, it can take a while. I mean, one of the biggest things in like even when we're looking at okay, when's the heat stress event gonna come? When they're really severe, when we don't drop below the 70s at night, like we've just experienced, that's when heat stress is gonna get the worst. If that animal doesn't have that ability to cool off at night, that we have some serious issues. So um, depending on how intense of a heat event, that can linger much longer. Um, we talk about in the feed yard all the time, and I it's it's really any animal ruminant, I should say. If if we start yo-yoing intake or or messing up that rumen, that rumen population takes time. It's fairly sensitive. We want to make sure that's maintained. And the more that we mess with that, I the longer it can take to kind of re-establish that. And we can have long-term effects. If you reduce intake, it can be very hard to get intake back.

SPEAKER_01 12:16

Um expensive then, too.

SPEAKER_00 12:18

It's super expensive. So we're losing gain, average daily gain decreases in the feeding period. If you have milking cows lactate that are in lactation, sometimes you might not get that lactation back, depending on how severe it was and and that duration, even of that heat stress event. True.

SPEAKER_01 12:33

Okay, so we've talked about the severity, we talked about the signs. Maybe let's take a shift and go into prevention. And I think some of this will probably be a reminder. But let's let's do that laundry list. What's the most effective management practices that producers can implement so that they can really deal with any of these heat events or whatever else might lead to the risk of some heat stress on their on their herds.

SPEAKER_00 13:01

So if we think about mitigation, there's a lot of stuff, but some of it can really be, it can take a lot of manpower or just an expense. So depending on your operation, there's there's different things that we can look at. Shades, number one, if we can stop that solar beating down on an animal's back, reduce that um excess heat load, that's something that we can do. Making sure that that animal can can have about a five mile an hour breeze over it. So if it's facility design, if you have a windbreak that's up in the winter, let's make sure we get that windbreak down before this next heat event comes through. If you have the ability to put fans in, I know Dr. Mater, there's been a lot of research. I recommend everybody looking up. University of Nebraska and South Dakota State University has done a lot of heat stress type research and they put out some publications on sprinklers or getting water on an animal's back. When we do that, we want to make sure that there's still that breeze to try to help mitigate that heat off of them. Stocking density, make sure that cattle aren't stocked too much in the pen, there's no crowding, make sure that pens are cleaned, they're not standing in mud. If the pens are wet, there's causing that extra humidity. Something that we kind of forget about a lot. We probably associate it more with the winter, but bedding. If if you have cattle on concrete, let's get bedding out in that pen, it can reduce that heat coming off that concrete, gives an animal a clean place to lay down that's dry.

SPEAKER_01 14:19

And I heard that it reflects some of the rays too.

SPEAKER_00 14:22

So absolutely, absolutely. If you have mounded pens, make sure the mounded pens are in good shape.

SPEAKER_01 14:28

Obviously, we also want those animals to be eating. So what kind of strategy we can we take on that end?

SPEAKER_00 14:35

Yeah. There's been some research and recommendations on on when to feed. Can we keep that feed cool for that animal? Um, so if you're if you're feeding that animal twice a day, can we give them a little bit less in the morning, a little bit more later in the afternoon? So they have that bigger meal at night so that feed stays a little cooler for them. If you're feeding once a day, again, you don't want to make too many changes, but maybe delivering that feed and transitioning those summer fed cattle to a later afternoon type feeding.

SPEAKER_01 15:03

Well, then let's look at water intake. We talked about that earlier. It's very critical, but sometimes they're feeling poorly and they just aren't going to drink enough. So, what do you want to say about any kind of management or any kind of tips so that we can get those animals to replenish what they're losing?

SPEAKER_00 15:22

For sure. I think the biggest thing that we think about is increasing square footage for water tank capacity. We kind of always have our run of the mill, what we've put in when we've when we've built the facility, it can actually increase um to about up to three linear square inches of water tank space per head. So when when you see heat event coming, you're looking at the weather, putting extra water tanks in there and doing it soon enough so that the cattle are like, hey, we got more water access so that they do have that ability. And are those water tanks able to fill up fast enough for the cattle that are at that water tank? Because they're all going to be there at the same time. Exactly. Exactly. Yeah. I mean, you really need to have enough um for cattle to drink about 1.1% of their body weight per hour. So yeah, for a 1400-pound steer, that's like 15.4 pounds or about 1.8 gallons an hour.

SPEAKER_01 16:09

That's a lot of lousers. So Formafeed has a product that can help with water intake, especially in a hot summertime or or you know, a heat event or or times like that, and likely other times. What would you like to say about Hydrolac and how we can use that as a water additive?

SPEAKER_00 16:29

Yeah, Hydrolac, it's a it's a dry pelleted product, and it's really um, it was designed and patented to be a heat stress product, but we've really kind of turned it into a stress product. It's got multifunction, so we've we've talked about the complexity of heat stress that that animal's going through on a metabolic standpoint. Um, it's targeting, replenishing the electrolytes. It's got some energy sources, some B vitamins to help with energy metabolism. Um, we have some yeasts and DFMs in there to help with rumen. So, really looking at rumen function, cellular hydration, and energy metabolism to help that animal metabolically through any sort of heat stress or stress event.

SPEAKER_01 17:07

And what about it increases the thirst? So that if you're hot, you may need to drink, but you may not feel like it at the moment because everything's going on in your body. So, what about hydrolac um increases that thirst for the animal?

SPEAKER_00 17:21

Yeah, so hydrolac has that electrolyte component. So if anybody's ever taken electrolyte, it's salty, right? That's that's part of an electrolyte, so that drives your water intake. So that'll help. It helps hydrate on the on the cellular level so that when that w animal is drinking, that animal is gonna want to drink. Um, it'll just kind of help balance the water and and cellular hydration and animal metabolically.

SPEAKER_01 17:43

Sure. And what kind of operations or situations have you seen the greatest benefit from using a product like hydrolac?

SPEAKER_00 17:50

Yeah. On the dairy side, lactation, fresh cows when they're transitioning. Um we have guys that actually leave hydrolac in all year round because animals are also dealing with cold stress. So on the lactation side, those cows are demanding an incredible amount there of water. They're very sensitive to heat. On the feed yard side, we see it um when those heat events come, putting it in a couple days before feeding it through that heat event to help kind of just maintain, reduce the true impact of of reduced dry matter intake and kind of help that animal metabolically get through that stress event.

SPEAKER_01 18:24

So as we as we kind of wrap things up here, if you had to prioritize, so what are the what would you say are the top warning signs that producers should not ignore when it comes to heat stress?

SPEAKER_00 18:38

Yeah, so the warning signs, I'm I'm always gonna go back to the weather. Do not ignore the weather forecast when they say it's gonna get hot, it's gonna get humid, it and for sure if it's not gonna get below 70 degrees at night. I that would be the number one. When you're actually looking at the animals, if you start seeing cattle respiration rates are increasing, hopefully we've already done some management stuff to prevent that. But if if you start seeing an animal experiencing heat stress, we've kind of almost missed our timeline to really truly help that animal mitigate. Um, because if if we were gonna put up shade, if we were gonna get more water tanks out there, it's still very important, but we want to be able to do that at the least stressful time. So if we didn't get water tanks out there, um, when can we do it in that day that it's gonna stress them the least? I know we didn't talk about it, but like working cattle, sometimes you have to ship cattle. We always say don't ship cattle at the hottest times of the day. Well, when the packer wants cattle and the trucks can get there or whatever your docking time is, we want to make sure that we're doing that efficiently. Let's not work them over 30 minutes, try to reduce as in our interaction with that animal um as least as possible so that we don't stress them out.

SPEAKER_01 19:44

And so going back to management practices, would you say shade would be maybe the number one thing? Sure.

SPEAKER_00 19:51

Shade, wind breaks. You want to make sure you're looking at anything, you want to cut vegetation back or anything around that pen at least 150 feet so that we're able to get air movement through those pens. Management is is number one to be able to combat heat stress.

SPEAKER_01 20:09

Well, this is the perfect time to talk about heat stress because we're just in the throes of summer. And so thank you, Allison, for joining us and helping us better understand heat stress, dehydration, and how to protect those cattle. And I'd like to thank our listeners for tuning in. We'll catch you next time with more guests and topics shaping today's ag industry.