Subscribe
Share
Share
Embed
Hosted by members of the University of Minnesota Extension Beef and Dairy Teams, The Moos Room discusses relevant topics to help beef and dairy producers be more successful. The information is evidence-based and presented as an informal conversation between the hosts and guests.
00;00;13;05 - 00;00;43;27
Brad
Welcome to The Moos Room. It's mid-May and pastures have slowed down. It's kind of crazy right now with the weather. We keep having ups and downs and actually yesterday I think it was 85°F, so it's been hot. Hopefully the grass will start growing again. We do actually need some rain here in western Minnesota to get our pastures growing. They were doing really well in early spring and starting to grow, and then they just stopped.
00;00;43;28 - 00;01;10;08
Brad
A few nights it was below 30 Fahrenheit, so it was kind of crazy. And there's a few pastures that just aren't growing. There's a couple. We're we turned out cows a couple days ago on Wednesday just to get the grazing started. A couple of the pastures that they're on the grass is maybe eight inches, ten inches tall, which is it's okay to start grazing.
00;01;10;09 - 00;01;34;15
Brad
I obviously have to watch it because if we don't get any rain, there's going to be no regrowth. So it's kind of struggling talking to some other grazing dairy farmers as well. And they're in the same boat just trying to get the cows out on pasture, but try to manage the grass because it's not growing so well. So hopefully summer will come and spring will come and it will rain and everything will be okay.
00;01;34;15 - 00;02;01;27
Brad
But it's been a challenge out here with all the crops. Most of the crops are in here in western Minnesota, but certainly we need some rain to start those. A little bit of spring drought going on here kind of gets me thinking about heat stress and how the cows will do that. And we did a study a year ago or so, and I want to talk about managing heat stress with precision technologies and kind of see what what we did.
00;02;02;00 - 00;02;32;03
Brad
Some know I do have the smack STEC bolus in our cows, and I had it in a few cows, I think here lately, maybe 40 or 50 we've had it in, but this spring we've decided or I've decided to put it in all the cows. So we've been doing that the last week, trying to get it in all of our organic cows and all of the conventional cows, so we can maybe do a little bit better job of either managing heat stress or trying to manage things just to see what might happen.
00;02;32;03 - 00;03;01;05
Brad
And it is interesting if you kind of look at some of the things that the smacks tech system is, is telling us rumination time. If I look at that across, we're averaging about 497 minutes of rumination today. And if I look at body temperature, our average body temperature right now 102.5. So internal body temperature just trying to look at what's maybe happening with our system.
00;03;01;07 - 00;03;26;29
Brad
But again these are our internal bolus that we put into cow into the they fall into the hopefully into the reticulum. Sometimes they go into the rumen and hopefully they're working out to be able to help with heat stress. One of the interesting things that I actually like about it lately is it's looking at water intake. So if you look at water intake, obviously that's a big component to maybe heat stress.
00;03;26;29 - 00;03;58;03
Brad
But these bolus are trying to measure water intake because as a cow drinks water, hopefully the water is cooler than the ambient air temperature outside or the cows body temperature. You see this decrease in body temperature internal body temperature as a cow drinks more. Right now cows on average are drinking about 86l of water per day. At least this is what the bolus is telling us.
00;03;58;03 - 00;04;23;20
Brad
And that's maybe about 23 gallons of water per day per cow. And that's been actually going up throughout our time as we've looked from maybe last October, November or December. So we'll see how the water intake goes. I think I always get concerned about water intake on pasture when it gets really hot and the cows see a decrease, so it'll be interesting to see what happens as far as water intake, what these bolus is.
00;04;23;27 - 00;04;47;02
Brad
But overall it looks like our cows are quite healthy. Based on the sensors, our health index has been going up. So I think the cows are doing well with our our nutrition program and everything that we've been working on. With that, if I kind of look at a specific cow or conventional cow, it's kind of interesting. Some of the things that you can see, it actually detects a magnet.
00;04;47;02 - 00;05;15;08
Brad
So it's telling me that there is a magnet detected in this cow, which we put all magnets in for hardware. If you specific cows, you get rumination. This cow here is about 330 minutes per day. Her average temperature is about 103 and a half, and it looks like her water intake is about 107l per day. So maybe 2027 gallons of water per day.
00;05;15;08 - 00;05;43;15
Brad
So it's kind of interesting to see what these things do in the sensor system, and how it might give us a indication of health status or water consumption throughout the time. So it'll be interesting as we move into the summer to actually see what happens. But I wanted to talk about heat stress and some of the things that we did with this bolus to that I think was kind of interesting.
00;05;43;15 - 00;06;18;09
Brad
Basically, we wanted to see where heat stress might occur in our cows based on this internal body temperature. And a lot of studies out there are measuring heat stress based on THC or temperature humidity index. And it's kind of a metric that combines air temperature and relative humidity to quantify basically heat stress in in animals, because obviously cows are highly sensitive to heat stress and it negatively impacts their feet intake or milk production or growth.
00;06;18;11 - 00;06;46;26
Brad
So there's a formula that calculates out what THC might be, and it accounts for temperature and humidity. And if you look at THC less than 68 is kind of a comfort zone. So no heat stress. At least this is what's based on industry standards 68 to 72. Kind of the animals really starting to feel a little uncomfortable. If it's 72 to 80, obviously that's kind of moderate heat stress.
00;06;46;26 - 00;07;07;04
Brad
And you see a significant drop in milk production. And if you're above 80 you see a significant loss in milk production, lots of stress in an animal. So obviously we like to keep THC less than 68. But you know, there's nothing we can do with the weather. So we have to be able to mitigate heat stress on our farms.
00;07;07;04 - 00;07;39;03
Brad
So we wanted to talk a little bit about what we found, and it might challenge some of those THC numbers in kind of some of our cows that we've seen. So we've been kind of monitoring with these sensors. I put smack stick in in 2018 and used it for some studies with grazing underneath solar panels and just in really I put it in more cows and we've been collecting data, but I'm really got interested in it now with this thought on heat stress.
00;07;39;03 - 00;08;06;14
Brad
And I have a student that's going to come in the fall, and we're actually going to look more at at heat stress and how this might work and mitigating factors that we can do. So basically, we wanted to see what would happen with with heat stress because historically, like I said, the dairy industry is kind of set heat stress thresholds at 68 for kind of model mild heat stress, 72 for moderate.
00;08;06;14 - 00;08;32;11
Brad
And that's really based on the exact moment that milk production declines. So we only see it really in milk production. And that's what we've been looking at for a lot of different years. So what really happens in the cow. Because if a cows body temperature peaks about two hours after a heat episode, an environment when it gets really hot out, it requires about six hours to dissipate that heat.
00;08;32;11 - 00;08;58;26
Brad
So she probably suffers for a lot longer than we actually think based on heat stress. So we think that we must look for different animal signs. And if subclinical signs of heat stress like rumination, rather than waiting for the bulk tank production to go down, we might be able to to see early signs of heat stress much quicker than waiting for the bulk tank.
00;08;58;26 - 00;09;22;15
Brad
So we looked at about 100 cows over a summer time period here in our research herd, and we had kind of different groups of cows. So we had younger conventional cows about 2 to 3 years of age. Obviously they're fed a TMR and they're in an outdoor dry lot. And we had the older cows, our older conventional cows four years and older.
00;09;22;15 - 00;09;47;29
Brad
So later lactation cows, third and fourth lactation cows again they're outside. And then we had our organic cows. So young cows first and second lactation obviously grazing during the summer time trying to get maximizing pasture as well. And then we collected weather data, local weather data from our research center. And we have all of this data from this max tech bolus which was selected continuously.
00;09;47;29 - 00;10;16;03
Brad
So if you look at the baseline, in an ideal weather situation or conventional, cows averaged about 476 minutes of daily rumination, and our organic cows were a little bit less, they kind of averaged about 450 minutes of rumination. So conventional cows may be a little bit more. And that's probably has to deal with TMR and forage. And really about a third of rumination variation is really tied to feed.
00;10;16;03 - 00;10;49;16
Brad
So the organic had a pasture diet that was much higher than compared to a conventional herd. NPH is a little bit lower 35 versus almost 50 NPH in a pasture based herd. So higher forage fiber drastically altered the chewing requirements, mechanics and digestive metabolic load. So what does that mean? Basically, the forage had a lot of influence in the rumination in these cows when they were not under heat stress, not under heat stress.
00;10;49;16 - 00;11;15;08
Brad
So we did some things to look at rumination and what happens when we see heat stress. And I know the summer that we did this, we had some massive heat stress events. It was 90°F or higher. And here in western Minnesota we can get some pretty high humidity where it's really sticky so we can get into really heat stress events here.
00;11;15;08 - 00;11;44;15
Brad
So what did we find? Basically, rumination was quite steady until we hit a breaking point. And after that it plummeted for a thigh. So the breaking point for the conventional herds was when they hit a thigh of about 64. This was this is a little bit less than kind of the industry standard that we see of 68. So about 64 in the conventional hurt and our organic herd.
00;11;44;21 - 00;12;18;23
Brad
So cows that were out on pasture a lot more time outside, 58 was the breaking point for those cows. And it really dropped significantly from there. Rumination plummeted by about six minutes for every unit increase in THC. Now we could say, well, six minutes. That doesn't necessarily mean a lot, but it can mean drastic. If you go from a thigh of 65 to 80, you can lose 80 minutes of rumination quite quickly.
00;12;18;23 - 00;12;47;21
Brad
And that has effects in milk production because of cows not eating. They're not producing as much milk. So it can really affect that. So environment and diet were certainly the big dominant variables in this heat stress reality. So if you kind of look at it specifically from cows, our young conventional cows, their kind of break point for I was about 64 and the older cows was about the same 64.5.
00;12;47;22 - 00;13;09;06
Brad
So the conventional cows, no matter if they were young or old, rake point was the same. And again, the young organic cows there breaking point was 58. So that really talks about heat stress and how it really might affect those cows, especially in an organic situation or a pasture based situation where the cows are out a lot more.
00;13;09;07 - 00;13;35;16
Brad
So there's this kind of trade off between these two cows where you're looking at internal heat. So obviously extensive pasture based herds are kind of considered more superior and welfare. And we can have a debate about that. But overall, our cows seem pretty healthy on pasture. But yet those cows reached heat stress six points earlier than the conventional cows.
00;13;35;16 - 00;13;56;25
Brad
So they're under heat stress a lot quicker than the conventional cows. And that would be today. It's supposed to get to be 72°F, and I would bet that those cows might be under heat stress today when they're outside, just in the direct sunlight, getting lots of solar energy on them, they're going to be under some maybe mild heat stress.
00;13;56;26 - 00;14;21;07
Brad
You know, they're not going to be panting, but I bet we might see rumination go down. And obviously you have this metabolic cost. So a high forage diet like the cows on pasture requires an immense breakdown of all of that feed. So you have all of this fermentation breaking down all of this forage in those cows, and it generates massive internal metabolic heat.
00;14;21;07 - 00;14;44;24
Brad
So really those pasture cows are organic herd. They're really running a hotter internal engine. I guess you could say they're generating a lot more heat, which is leaving the cow with less bandwidth to absorb the environmental heat from the sun and humidity. So those cows that are on pasture are going to see heat stress a lot faster because of that.
00;14;44;25 - 00;15;12;11
Brad
What do we see? You know, we maybe start to see rumination dropping at about 5758 THC. And we need to think about that and how that affects the cows biology as well as can they survive the heat load. Obviously, we don't really see this traditional milk drop until we have THC close to 70, and our cows are showing that much earlier with rumination.
00;15;12;11 - 00;15;35;15
Brad
So if we really manage heat stress based solely on milk yield, I think we're kind of failing at animal welfare. I think we really need to be looking at these sensor systems to be able to help manage heat stress. And I think that's where this bolus smacks tech bolus might come in. If you're interested in that and helping to manage heat stress or mitigating heat stress, maybe this might be the one for you.
00;15;35;16 - 00;15;56;29
Brad
You know, I have lots of different sensors on our cows, and I'm each one does something differently. And I kind of like different aspects about them. And this being able to look at internal body temperature might really think about that and how you might manage heat stress during the day. So obviously our cows are a complex system. We know this.
00;15;56;29 - 00;16;21;08
Brad
They have diet. You have high forage diet. Obviously genetics played a role in this. And we're going to start looking at that maybe a little bit more. And how Holsteins handle heat stress versus some of the other breeds in our herd, whether it's Jersey or some of the European dairy breeds. Obviously management plays a big role in this, in access to shade automated cooling systems.
00;16;21;08 - 00;16;44;11
Brad
If they're in a barn, feeding schedules might act as a primary buffer against some of these other stressors. So determining when you might feed your animals to actually reduce heat stress. But really, rumination is kind of the single thread that ties a lot of different things together. So if you can monitor rumination in your heard, you might be better off.
00;16;44;11 - 00;17;04;14
Brad
And especially with this bolus where you can monitor that internal body temperature. So what are some of these implications for farm management that we might see. Well we could adopt these internal sensors. And I know quite a few farms that have had these smack stack sensors. And a lot of people have talked to me about them and how they work and, and what they might do.
00;17;04;15 - 00;17;29;29
Brad
And it really helps us move beyond some things. And we can look at internal body temperature across many different animals and really think about heat stress a little bit better. And we can really think about lowering heat abatement thresholds. You know, maybe we shouldn't wait till we hit a high of 68 until it gets to be 80°F. By that time there's already heat stress going on.
00;17;29;29 - 00;17;56;21
Brad
So we either need to update our environmental control system. So fans soakers if you're on pasture shade is important to really help mitigate heat stress because when we hit 58 to 60, especially in these pasture based herds, we might help prevent this subclinical rumination crash that we see. You know, we don't see the rumination crash until it gets really hot, but we might be able to detect that a little bit earlier in our cows.
00;17;56;22 - 00;18;20;21
Brad
Obviously, we need to configure our dashboards, our farm software, to trigger alerts that are based on daily rumination drops. And we really should be looking at rumination. I know sometimes we like to use these systems for activity based and breeding, but I think treating rumination as an early warning system can really protect the health of a cow before we see this production loss.
00;18;20;21 - 00;18;40;16
Brad
So I think we can really do some amazing things with these internal body sensors being able to detect temperature. We can look at water intake, and I'm kind of excited about that to see how water intake goes on managing pasture this summer. But it's kind of interesting. And I think we need to really think about heat stress as we move into the future.
00;18;40;18 - 00;19;02;16
Brad
It's got me thinking about heat stress already. When our pastures aren't growing, we don't have any rain. We're in a slight of a drought. So will there be some heat stress? And how do we do that? I know we're going to put some shade structures out with our conventional cows this year, and hopefully with the organic cows, we've done some portable shade systems as well to help mitigate heat stress.
00;19;02;16 - 00;19;23;28
Brad
So with that, hopefully you've learned a little bit about some of these sensor systems and that maybe heat stress starts a little bit earlier than what we would expect based on our our norms. So if you have any comments, questions or scathing rebuttals, feel free to contact me at the room. That's MLS rom.
00;19;24;01 - 00;19;33;28
Brad
Or find us on the web. University of Minnesota Livestock Extension or WC Rock dairy. And with that, I hope you have a great week by.