Transcription
[Music]
Good evening everyone and welcome to the Real Science Exchange, the pubcast where leading scientists and industry professionals meet over a few drinks to discuss the latest ideas and trends in animal nutrition.
Hi, I'm Scott Sell, and I'm going to be your host here tonight at Real Science Exchange. Tonight, we have a truly fascinating topic to dive into: the role of the mammary gland in governing calcium metabolism.
Joining us is a very special guest, Dr. Lur Hernandez, a renowned researcher and professor from the University of Wisconsin. Dr. Hernandez recently delivered an insightful presentation for the Real Science Lecture Series on October 2nd, and you can find that presentation on our website at balm.com/science.
We're thrilled to have Dr. Hernandez with us here today to expand on that discussion. Now, Dr. Hernandez, welcome to the Real Science Exchange! I guess this is your first time at the pub, so welcome!
Thank you! Any special drinks that you have tonight?
I know maybe, uh, maybe not so, but if you were at a pub tonight, what would you be drinking?
Probably wine.
Good, good! Red or white? Do you have a preference?
Definitely red.
Good stuff! I love a good red wine. I see you brought a guest with you here tonight. Would you mind introducing your guest and how you decided to bring him along with you?
Absolutely! Well, I was very honored that Dr. Tom Overton agreed to join us. Tom, I've known since I think I was in grad school. I probably read all the papers and have gotten to know him more since I became a professor. I think I mentioned offline that I am not a nutritionist; I'm definitely a physiologist. So, I always like to have a good nutritionist available to chat with, and I think he's one of the best—definitely the most practical—and he works in the space I do. So, I think he was the right person to choose to talk about this.
Yeah, absolutely! I'll second that. Tom is one of the best. So, welcome, Tom! It's great to have you back here. This is not your first time at the pub, so...
No, it's not! Thanks, Laura, for the invite. It was really nice to get that opportunity to join here today.
Yeah, thank you! So, Tom, anything in your glass tonight you'd like to share with us?
A bottle of tonic.
Well, we thank you for joining us, Tom. And not least, I'd like to introduce my trusty co-host, Dr. Jeff Elliot. Jeff, this is not your first time here either, so what's in your glass tonight?
Well, since I work remotely in my home office, no one can tell me not to have a cocktail while we're doing this. This is a take on the Tequila Sunrise called the Holiday Sunrise. My daughter came up with this over a holiday competition that we're doing this season, starting Thanksgiving and going through Christmas. Each of us has to come up with a seasonal cocktail, and we judge them. The prize for the winner gets, I think, a prize, and I'm probably having to pay for that prize, but I haven't been told what the prize is yet.
Yeah, but she did a really good job, so I'm having it again.
So, good deal! Well, thanks for joining us tonight, Jeff.
Now, I've been in a rut lately, and I think I mentioned that on my last podcast. I've been having Woodford's every time, and so I decided I was going to have something different. I went and bought a nice bottle of Widow Jane, but that plan was foiled. Our pump quit working here at the house, and we didn't know what to do.
So, my wife, Mary, says, "You know what? Our new neighbor—I've never met this guy—he's a retired plumber, electrician, or something. I think I'm going to give him a call and see if he'll come over and look at it." I'm like, "Okay." I said, "Gee, can I pay?" and he says, "No, I won't take anything."
But while he was there, we got talking about bourbon, so he likes bourbon as well. I tell you what, I got a bottle of Widow Jane that I'm willing to part with. So, Mark—I don't know his last name—Mark's got my bottle of Widow Jane. So, that's my story this evening.
Anyway, all good plans, huh?
Folks, thank you for joining us tonight. I look forward to a great conversation, so cheers!
Yeah, cheers!
[Music]
The economics of feeding Reassure. Precision Release Choline Reassure is fed during the transition period, and because it's fed for such a short period of time, it costs just $15 per cow. Yet the benefits will continue to generate income throughout the year.
Cows fed Reassure produce 5 lbs more colostrum, which pays for your Reassure investment on the very first day of lactation. Cows fed Reassure also produce 5 pounds more milk per day, every day. That means after the first day, every day is payday.
Invest in Reassure during the transition period and recoup your investment on the very first day of lactation. After that, you got it—payday!
[Music]
So, Lur, I'm going to jump right into it. In 2024, you hosted a great webinar before the Real Science Lecture Series that led to some interesting conversations and questions. Can you please give us a quick overview of that webinar and help explain the topic of the role of the mammary gland in governing calcium metabolism during the transition period?
Sure, I'd be happy to. So, for a while now, I've been working in the field of calcium by accident. I really am a mammary gland biologist and was trained to think about things in the production of milk and how that impacts the mom, or the cow in this case.
I ran into some things along the way that suggested that the hormone I'm interested in was regulating calcium, so I started doing a bunch of experiments over the last 13 years, and lo and behold, I sort of do calcium now.
Because I was trained by someone who really thought—Dr. Bob CERR—that there were things coming from the mammary gland that could manage what the cow was doing. So, I've been working on that and looking at how we can do things in the pre-partum period, particularly to manipulate what's happening in the mammary gland to make sure the cow has adequate not only endocrine status but nutritional status.
Cows need to be healthier as a whole from a reproductive standpoint, a nutrition standpoint, and an immunological standpoint. What we've seen across a few different types of studies we've done, depending on manipulating a bunch of different things, was that it's really this drain of the mammary gland of the milk, which has lots of calcium in it—the highest mineral content—that was triggering all these mechanisms.
I went back in the literature and dug up a really cool paper that I think I mentioned in my talk, back when you could do fun things like remove organs and add stuff back. It was a paper by Jesse Goff, where they mastectomized some cows about two months before parturition.
What they showed was that the cows could maintain normal calcium if they weren't making milk, but if they were making milk, their calcium rapidly decreased. So, we kind of went through that, and we've been looking at different ways to improve that.
In my very physiologically manipulative experiments, I crossed paths at one point with Jess McArt, looking at a lot of data that Tom has put out from his lab. We're seeing similar things from an epidemiological perspective and applied nutrition perspective, and what we were seeing really supports this phenomenon.
It's not the only one that occurs; you could say the same for fat and energy and different components that are being secreted into the milk that are having this what we call negative feedback. That's what I've been studying now, and I've been looking at a bunch of different ways to manipulate that and try to describe what's actually happening so that nutritionists and producers can make better decisions knowing what's occurring and what's the best strategy for their farm.
Yeah, I was watching your lecture again today in preparation for the podcast, and I got a little bit of an offbeat question for you. Recently, Dr. Van Amberg presented some data showing how the percent of protein and fat has exponentially increased over the last few years. It got me to wondering, have there been any changes in mineral content, be that calcium or phosphorus, and how has that changed anything?
It's a great question. Calcium and phosphorus are pretty stable in the milk relative to protein or fat, though fat by far is the most variable and protein being the second. But it takes quite a bit to change the amount of calcium or phosphorus going into the milk.
The one thing I would say that you can consider—and I don't know that it's a fact—is that with higher protein secretion, you get more calcium and phosphorus because there's calcium and phosphorus attached to the protein that's being secreted into milk. So, what we would call the bound calcium and phosphorus might be higher, but not necessarily the free.
Got it. But going back to his question, it's one of the questions I'd written down that is more philosophical, thinking about what is normal, first of all, and has that changed over the last 50 years, especially relative to where we are on milk production?
So, Laura, you're suggesting that calcium and phosphorus are hard to change, but they stay fairly the same. But these cows are producing a lot more milk than they were 10 years ago, much less 50, right? So, I just wonder, has normal changed?
That's a great philosophical question because it has. I would say that one of the things that's difficult with interpreting what we do now versus what someone did in 1985 is huge because they are producing more, the animals are different sizes, the feed is better. There's a lot to be said for what we do.
I do think that normal has changed. I think there's been some adaptation of the animals to maybe be more hearty, should I say, but I think they're more efficient. Certainly, they were more efficient when they were on BST; that's without a doubt. But even without BST, they're fairly efficient.
I don't know tons about proteins, so don't shoot the messenger or anything here. It's just a thought exercise, but even if you think about some of the stuff they do with protein, they're always trying to change things every—what I read anyway—is like two to two and a half percent. I can't figure out how much of a difference they're making in any direction.
It's hard to tell because maybe quality is better. I don't know. Again, I'm not a nutritionist, but cows are doing really well, and we've adapted them to do so. So, I feel like normal has changed, and that's where I struggle with absolute concentrations of things because we live off of that. That's what's published, and sometimes I think we're saying something could be ill or not well, and she may be fine.
You know, I think normal has changed, right? I mean, but I also think it's changed for the better. We're focusing on issues differently, right? This goes back even to my time, but I mean, clinical milk fever rates at 5 to 10% of cows calving probably was not unusual.
I know for sure that when I started back in 2000, herds with six to eight percent of fresh cows on a herd—that was pretty typical, right? And we accept none of that anymore.
I do get occasionally that Laura and I have some academic colleagues who will say that we haven't made any progress in transition cow health and things like that, and I quite firmly dispute that because we know at the farm level, indeed, we have.
Well, just look at somatic cell counts. Yes! I mean, our farmers, supported by our agro-business, allied industry folks, and university folks, have made tremendous progress. It shows up in not just health but also in milk yield and reproduction.
All this stuff is multifactorial, but you know, 25 years ago, Laura, probably nobody was thinking about subclinical hypocalcemia in the '80s or '90s, right? And that's now where the focus is.
If you told me 15 years ago that there'd be as much calcium biology research and epidemiology as nutrition as we've had since then, I would have been like, "Oh, we figured calcium out a long time ago." It's astonishing what your lab has been able to unravel from a mechanistic standpoint or otherwise that really has supported some of our ability to get this right out there.
I think so, and I can remember the first grant I submitted. Someone said—maybe it was you, Tom, I'm just kidding—maybe it was, but someone actually put in there, "We don't need to study calcium; it's..." I was like, "Oh, okay. Maybe I am wrong."
But it's been fun because I think, to what Tom points out, it's been a synergism of producers, veterinarians, and academics really trying to say what is happening before making any definitive claims and how we can adapt stuff better.
It's amazing how healthy I think a lot of our animals are.
Tom, you talk about it being multifactorial. Is it genetics? Is it management? Is it our understanding?
Yes!
Yeah, I love it!
Yeah, I wouldn't put an emphasis somewhere.
Well, you know, I think it probably depends a little bit on what it is, right? I think for production traits, components, things like that, genetics is certainly in there as well as management.
I think for the things that we're talking about here today, much of it's the management around it—dietary and otherwise—that helps these cows make it through this period better than they used to.
Not to say we don't have opportunities still, right? Because we sure do, and there still are.
Lur, you did a nice job. There are a lot of questions out there, right?
But I think our understanding has come a long way, and our ability to manage calcium metabolism has come a long way as well.
I'd say, too, that digging deeper has provided more opportunities for farmers to use practices that work best for their management system rather than only being able to tap into one thing.
Here's the one thing you can use, and try to shove a square peg into a round hole kind of situation.
Whereas we have such a large range of size, type, farm, milking system, management practice, and people working there.
One thing my colleague Milo Wilbank always says is that double-off sync works, but they have to give them the shots when they're supposed to, right?
I think that could be said for new pre-fresh nutrition too or anything else. If you have more tools in the toolbox, you can use the one that the people on your facility and farm can implement and implement correctly, and know how to handle the animals.
You know, talking about tools, you presented some data during your presentation on some of the interventions that are being used. Can you talk a little bit about that data? Maybe what your recommendations might be?
Sure! I think the classic things that are out there, like the really low input kind of strategy, would be a low potassium diet. There are folks who still do that, and that's good enough for them. They can do it consistently and manage their herd pretty well from a pre-fresh standpoint.
The other two would be clearly negative DCAD diet work. There are a lot of them. If you have some kind of negative DCAD diet metabolic acidosis, your urine pH works really well if the cows are eating it, if the diets mix well.
All in all, those things work. You can do it for a long period of time without having any issues with the cows. Depending on what your penning strategy is pre-fresh, that might be the easiest.
There's a newer technology to the U.S. anyway that was being used more in Europe, and that would be the zeolite clays. Both of which Tom and I have done a little bit of work with.
That is a binder that binds two-plus ions, like magnesium, phosphorus, calcium. It was largely thought that it was primarily a calcium binder. My data, and I think more data now, suggests that it probably works primarily through a phosphorus reduction mechanism.
That is a more acute treatment of 10 to 14 days pre-partum, which, if you can do it, appears to work well for calcium purposes. But you can't really feed it for an extended period of time; that appears to be somewhat contraindicated.
They're still working out some of the information related to that and application in the U.S. because all the data prior to Tom's study was performed in various situations in Europe.
I've heard that in some systems where they are grazing and maybe only milking one time a day, that might be simpler for them to implement.
But I think I've heard from producers that DCAD works really well if they can do it. The zeolite clay will work really well if that works for them.
But again, it gets back to your grouping strategy, compliance by the staff on mixing, and your urine pH if you're doing DCAD. Those kinds of things become important.
What we've shown is that you have to be looking at things from a couple of different ways because the clay is a phosphorus-driven biology. Management of cows is different compared to management of cows in a metabolic acidosis, which is largely a calcium-driven biology.
I think there are questions from veterinarians surrounding low phosphorus and what that might mean long-term, and some of the outcomes in post-fresh cows. If you do have a cow that goes down, she's almost certainly low phosphorus and not low calcium.
I don't think people were thinking about it that way initially, and that's why the work we do is really important. Because in real life, in real time, the vet or the farm staff has to make a decision of what to do.
If you give a cow who's low phosphorus calcium, you can have rebound milk fever. So those kinds of things are really important.
From a pre-fresh strategy, those are the two tools we have in the toolbox beyond managing potassium. But I'd be curious to hear what my colleagues have to say on that.
Yeah, I mean, Lur hit it really nicely. I think, of course, a low potassium diet is just partway on the way to low DCAD, right? Because it's one of the cations managed.
So, Lur, I watched your webinar shortly after I was invited to join you, and I also watched it at 5:30 this morning. What a way to wake up! That and a good cup of coffee was a nice way to start the day.
But anyways, I think one of the things when you present this stuff—and I think it's really interesting because you kind of focus this a bit—right? Because a lot of us think about metabolic regulation in the transition cow, and it's just like all this stuff happens in all these other body tissues to just throw stuff at the mammary gland.
You kind of think of the mammary gland as the receiver in this case, yet you do a great job of reminding us that the mammary gland is actually a very active participant in that regulation and calling the shots.
I think that's fascinating to you. It kind of takes me back also to some of our mutual mentors, like Bman and, of course, your primary, you know, Bob Kerr.
One thing that also struck me, listening to your discussion on calcium balance and lactation, is that I either didn't realize or didn't pay attention, but you say these cows are in negative calcium balance through 150 to 200 days in milk. That's amazing!
Yeah, it's quite overwhelming at times. Every time I've spoken with Jess, and I just saw RTH Neese a couple of weeks ago at Purdue, I'm like, "Man, we need to get a machine that we can put the cow through so we really know what her bones look like."
Because she's very resilient, and so are all mammals when they're lactating. It's quite impressive that they're able to get to this neutral and reacquire what they need.
That biology is always stunning to me. That's kind of one of the conserved phenotypes of mammals in general. You want to make sure they're getting enough calcium, but there's this compensation—a lot of different things that's occurring from her directly as we keep pulling milk out until she can hit that peak phase and start to shift gears again.
Because that's not a lot of time between that time and when she calves again, right?
It seems like she's got a— I think you said there's like eight and eight and a half kilos of total calcium in bone. Is that total in bone?
Yeah, so how much does she go down to? Do we have any idea?
We don't really know. I saw some really, really old papers, but they were largely in sheep. I haven't really seen a good one in cows that can talk about that.
This is why Ruff told me I can get a 600-kilo cow into the horse micro CT, and I was like, "Well, I don't know. That might be still too small, Ruff."
But I think I'd really like the opportunity to solve that because maybe she's completely different, or maybe it's not as robust, but we don't really know.
The only way we've thought about is taking a biopsy from the pin bones to see if we can get at least turnover within the tissue because it's really hard to decipher an animal that size without ashing her, which is not what I want to do.
So, you know, from a nutrition standpoint, should we be feeding more calcium in lactation?
Possibly! That's what it sounds like.
Yeah, right? Or is some of this just hardwired into her regulation and metabolism where she is just going to her bone? Is her bone just going to do this regardless of what else we do?
You think about things like 25-hydroxy vitamin D, and I mean, all right, boy, you know, it's—say in humans, they'll lose up to 10%, sometimes 15%, if they're breastfeeding only for the first six months.
So, it's pretty hardwired that she'll keep pulling it until they get to parity, right? Then she'll start to, like, I don't know if it's that they rapidly increase absorption and that allows for more storage, or if it shifts the hormonal signals.
That's one thing I'd like to do as well and be able to do it in a live animal accurately.
Because that's the other part too is the gut part, right? Trying to understand what's happening in the gut in real time because that's a difficult thing to get at without using calcium-45 or something, which they are not in favor of you doing these days.
So, trying to understand that better is like what's the rate of absorption within the gut and that in relationship to her endocrine status and her milk production.
I'd really like to do that and be able to compare it across stages of lactation, so like the late pregnant cow, the early lactating cow, and then the cow that's at 150 to 200 days in milk, and try to see if we could put that puzzle together.
So, Lur, you know, I guess I've kind of accepted, you know, as I came into this industry that multiparous cows are more prone to milk fever. You know, that's what we learned first.
CF heifers don't, but why? Why? You know, we just accepted it, and now it's making me think, why is that? Is there less ability for those cows for bone resorption?
Or is it in later lactation when the calcium demands are not great, they're not getting enough calcium back into the bone that they don't have it for the next lactation? Or is it just a biology we don't understand?
Those are all great questions. I don't have a definitive answer, but I don't know if as they age, they're just not as effective in the absorption of the nutrients, or if there's also something related to—because we do know females have a harder time with their bone because of estrogen.
I don't know how estrogen declines overall in a cow, like in her lifetime, as it compares to a human. But it's one of the things that they've seen in humans where those who have offspring later in life can have issues with bone turnover, and they'll see fractures sometimes in those lactating women because their density is lower due to their estrogen levels being lower.
On the same side, I wonder this because we've learned too what you just said—it's what I learned—but in those growing animals, is there some kind of missed opportunity there too that we don't know what's happening in them because they're still depositing bone?
They see those also occur in, say, teenage women sometimes as well. When they have a baby and breastfeed, they'll have problems as well because they're still depositing bone until they're like 25.
So, I don't know if it's an endocrine thing, an efficiency of their gut potentially, their absorption, or if it's also like real technical stem cell sort of thing, kind of like you see in the mammary gland over time as lactation goes on or you go through subsequent lactations.
I think it was like Tony Kuko that did this work, but they have less and less stem cell populations in their tissue to have regeneration of the tissue.
So, I don't know if that's a thing too, but there's these disparate ends of young and old, and then there's the ones in the middle that do mostly okay.
Yeah, it's intriguing for sure. I even had a nutritionist call me one day, and he asked, and I think you and I talked about this at the Cornell conference.
He asked me about vitamin K2.
Oh, yeah, you did!
I was like, "I don't even know what that is." He said, "Well, Balchem makes it." I said, "Well, we make it on the human side."
Scott, I don't know if you're aware of this.
Yes, I am!
But apparently, one of its functions, I think of vitamin K, is blood clotting, but K2—vitamin K2—part of its function is getting calcium into the bone. It expedites that.
He was wondering if that, you know, could we feed some of that late lactation to help just basically the longevity of the cow as well—not just about calcium mobilization, but better bones.
So, it was... yeah, there's... we don't know what we don't know.
Sounds like a project!
Exactly!
So, you know, Laura, one of the interesting areas that we kind of get into is, you know, what farms do at the—or what producers do at the farm level to give calcium, right, in different ways and forms.
There's some older data—not that old, I guess—where folks have given 500 mL of 23% calcium borogluconate IV to cows that were just subclinical, and they got a big spike in calcium and then some rebound hypocalcemia after that.
I was really interested to, when you were talking about Megan's study there, right, when you were basically just trying to use calcium gluconate post-calving.
What was interesting in yours is that, you know, a farm gives that at 500 mL in a relatively short period of time, whereas you guys spread it out over like 20—I mean, I think it was 100 mL an hour for about that...
Yeah, 24 hours.
And yet they still crashed essentially when you guys quit doing that calcium.
So, I'm curious what you're... you know, we've been Jess and I have both been pretty, you know, one when a farm has milk fever issues, like really trying to get to the bottom of, okay, what is that farm actually doing beyond what might be a diet, i.e., calcium administration?
But, you know, I find that really interesting that even in your case where you spread it out, they still crash pretty hard.
Yeah, and this gets to the timing, and timing is everything.
That's where I showed her that data one time when we were both on a speaking thing, and we were talking, and then she showed me some of hers and Ruff's data about the classification.
That was where this really became interesting because we were trying to keep the cow normal calcemic for the right after calving.
I think during that time, most people were trying to take a blood sample within the first 24 hours of calving and making decisions—subclinical, clinical—this is what our population looks like, this is what we need to do.
So, our goal was to really say, like, these—and what my hypothesis has always been—is that you have to have a decrease to trigger negative feedback. That's how negative feedback works.
So, we wanted to keep the cows normal calcemic during that first 24 hours, and we were just adjusting our infusion rates based on the cow's response to the calcium.
What we saw was because she never decreased—or none of them decreased during that first 24 hours—when we stopped giving them calcium, they had their negative feedback response, and it was like we need to go down because we need to reset everything to come up to what's appropriate.
We saw that even in the cows that were receiving the negative DCAD diet, so we'd prep them to calve better.
Then we did that, and that kind of erased our negative DCAD diet response that we saw when they were just getting controlled saline.
To me, what that says is that they need that time.
When people ask me what to do, I try to get to 48 hours before you take a blood sample, please try!
If you really are itching to take one earlier, wait till 36, but ideally wait for 48 hours because calcium—and I think I showed this in the talk—is really a combination of when you decrease your calcium, how far you decrease the calcium, how long it stays decreased, and when it decreases.
That was exactly what Jess saw in her classifications of the delay, the persistent, the transient, and the normal hypocalcemic animals.
When they were classifying cows in that way and looking at these clinical outcomes of DA or, you know, take your pick, it came back to this 48-hour time frame.
Because you could take a blood sample at 12 hours, and it might be normal, but she hasn't gone down.
If she goes down later on in those cows that they classify as your late delay hypocalcemic cows, you would miss those.
Similarly, you might get the opposite—treat a cow that you didn't need to treat because she was at her nadir and coming right out of it.
Of course, it all depends on what your cut point is, which no one seems to agree on. It depends on what your outcome variable is.
That has been what I tell folks when they call me. I've told them, like, if you can wait—unless a cow is ill—let her be.
If you think she needs a bolus or an IV, sure. If you know she had milk fever last lactation or maybe had a DA or RP or some other combination thereof, maybe then give her a bolus too.
Or if she's a crazy high producer in her fourth lactation, she could probably use it.
But in general, if you could leave them alone for 48 hours, they'll probably be all right unless you're having bigger issues.
That's what I try to tell people when they ask me for advice, which is here or there—not super often.
Yeah, and it's interesting. So again, people that do some of this, they do it with good intention because they think these cows—I mean, their heart's in the right place, right?
They think, "Okay, cow needs calcium; therefore, I give calcium."
And yet, at times, it's like, I don't know, it takes a while, and sometimes they're reluctant to admit what they're really doing.
You gotta kind of keep digging and digging and digging, and then it's like, "Oh, okay, yeah, all right."
So, Jess and I have had a few of those experiences together.
It's also, you know, pulling the veterinarian in, the nutritionist in. Of course, you get milk fever, and nutrition is blamed, right?
So regardless of what's going on at the herd level, and so, you know, it's why you just gotta try to understand it all.
But it's really, really insightful.
So, I'd say too, and the other thing we learned, and why I think studying this area is important, or any of these really metabolic-type health issues and understanding the physiology, is you can't give calcium to a lot of those exilic cows.
Because if they go down, I don't know what you guys saw with Allison's study, but they're usually low phosphorus cows.
Unless you have a blood phosphorus, you don't know that.
So you give them the calcium, and then a lot of times they rebound because what they really needed was phosphorus, and their calcium was just fine.
At least that's what we saw in our experiment.
We had to hold the farm staff back. I had it explicitly in my animal care protocol: run the ion before you give a treatment.
Because, you know, you could be giving them the wrong thing.
So, yeah, we've done that at times. In that particular study, we actually didn't have to treat anybody, so we never...
That's great!
We really never brought into that issue of, "Okay, what do you do with her?"
Yeah, I think we had a couple, so it wasn't like a lot, but we had to take a couple off our study because they just gave the calcium.
Lo and behold, their calcium went super high, and it was a phosphorus issue.
I think that's why our science is super important for the industry.
There's also... I'm curious, you had that study where you did the prepartum chelation, right?
The prepartum, I think it was six hours a day for the last seven days, if my notes are accurate from this morning.
Good job!
You know, I saw they needed more EGTA as they approached calving to really chelate that calcium, but I was curious to know... I didn't look at the—I don't know if that's published or not—but yield colostrum yield in those cows, what does something have?
If you're chelating, you know, were they different?
Yeah, they were. In this study, it's not huge, right? Because we're doing highly manipulative things, but we didn't have any colostrum differences.
What I've learned, and the purpose of doing that, was to make these arguments that all these things work differently.
If you're manipulating calcium, it does one thing. If you're manipulating phosphorus, it's another. If you're dealing with metabolic acidosis, that's something else.
They're all to the same endpoint, but understanding what each is doing would help you manage better.
What is one versus the other?
When we were doing this, we were focused on understanding specifically what was calcium doing from this standpoint.
I thought we were going to have to use not as much EGTA as we did.
The early lactation cows that we've done EGTA treatments with, they are very resistant to that calcium.
I think, you know, it's an effect of lactation.
I suspect at this period of time, because of the amount of colostrum being pulled together and the higher protein concentration of colostrum, there was probably a significantly large draw at that period of time.
Plus, whatever the calf needed as well on top of it.
I believe that's largely why they were more sensitive than even the early lactation cows.
But it was just another indicator that the mammary gland is like, "No, it is for me!"
And like, "Cow, you stay okay, you stay good enough, but they were really fighting with each other on trying to take it away from her because she wanted it for partitioning again for the calf and for her milk."
Yeah, I think that happens with a lot of nutrients, right?
M gets the priority.
Yeah, yeah.
So, I don't know. It's kind of funny. I didn't realize I was saying anything too crazy, but I went to speak at Cornell the first time, I think when I was in Syracuse, like in 2014 or something, and Dale was in the audience, and he's like, "I am so glad you're saying this."
I was like, "Am I that radical?"
This was the first thing I learned from Bob.
But, you know, it's definitely a paradigm.
Bob, Kevin Hartine would be another that I think very much thinks from that perspective.
When you read all this stuff in all these maternal species, it is quite impressive what these mothers can do.
That's really the basis of my science.
So, yeah, kind of a question for both of you.
Laura, you started off saying that, you know, in the very beginning, people said, "Hey, we know everything about calcium," and obviously we've talked about a lot of different things today that we don't know.
Where should the priority be in at least the near-term, mid-term research that needs to be done in this area in calcium?
I think that there's a lot of opportunity still yet to understand.
For one, because there has been more uptake of exil it, and it's a newer technology in the U.S., understanding how that works biologically.
Because DCAD is really tried and true, but it wasn't at first either, and it took some time to get there.
I think we should continue to be rigorous in our quest for understanding that.
I also think that personally, because I'm interested in it, is this understanding of the gut—what's happening in the mammary gland and in the bone in an actual cow.
You know, in a Holstein or a Jersey, but a dairy cow—and understanding that biology better.
I have some thinking of ways to do it without costing a vet school probably many millions of dollars to buy a very nice fancy machine, but some other thoughts of how we could maybe get at that, like by measuring foot health and stuff.
Those are high-stress points for cows.
Different ways we could maybe answer some questions.
But I do think those are really important, and understanding in general—not just calcium, but I think in general as nutritionists and physiologists, we should look at things at these different components of lactation.
A lot of times, our studies are focused on the easiest animal to handle because they're more in control, but data is so different in these animals in a pre-fresh cow than it is in a mid-lactation cow.
We have a tendency to extrapolate because that's our best knowledge, right?
I think more work should be done in those because lactation is very dynamic.
Yeah, Tom, from your perspective, what would you say?
You know, a couple of things, right? I think from a field practical perspective, both Laura's study and our study binder, you know, and actually when we did ours, it was all about calcium biology.
There was no discussion of almost anything else or there, like, "Well, maybe phosphorus is in here somewhere."
You know, but we were both at 500 grams per day, and at the time we did it, it was like, "That's it, period, end of story."
It doesn't matter what else the diet looks like, things like that. It was just that.
Now both companies that are marketing these binders are now relating it to a certain proportion of grams of phosphorus, which brings them down into the 300-plus or minus range, right?
So, versus the 500.
Nobody's really done that work.
Nobody's looked at these things in a one-group dry cow system.
I also share the reluctance to feed them for longer than the standard close-up period just without just things charter waters.
I think from a more scientific standpoint, accounting for where all the calcium goes, right?
It just feels like we don't have a great interest in either pre-partum or post-partum of, you know, because, I mean, again, you get a little bit of calcium in the urine, but not a lot.
Definitely get some in the feces.
Obviously, you got some going in the bone or milk, but I mean, you know, I don't know.
When we try to do some rough math, it's not always easy to account for where things are going.
It's got to add up to...
It's gotta add up to 100!
So, I don't know. There's still stuff here biologically to sort through, I think.
Yeah, you know, kind of circling back to something, Tom, that you had said earlier, and I think Jeff had alluded to as well, is those, you know, they don't start—they don't reach energy balance until later lactation.
And do we know if they are depositing enough calcium back?
And if not, how do we determine that?
And then how do we improve upon that?
You kind of mentioned nutrition, or is it Jeff mentioned the K2?
That is kind of intriguing.
We do have that.
I have no idea whether or not—I think it's expensive, I've heard.
But it seems to me that might be an area as well.
Sounds good!
Looks like the girls then just flashed the lights. That means it is last call.
With that, what I'd like to do is ask each of you to let's go around the table and what are just a few takeaways that you'd like to leave with the audience tonight?
And, Jeff, if you don't mind, would you lead us off?
Our last call question is sponsored by AminoShure XM, Precision Release Methionine—the next generation in amino acid balancing.
With AminoShure XM, you can save up to 5 cents per cow per day on your methionine investment.
Try it today and receive an additional 2.5 cents per cow per day savings with Balchem's limited-time rebate offer.
Contact your Balchem representative to learn more.
Yeah, certainly!
Well, I'd love the reference because I'd forgotten about it too.
It seems like 20 years ago, I'd heard that, "Oh yeah, we know everything there is about calcium now. We're solid there."
It goes back to the idea that we don't know what we don't know, and there's still a lot to discover.
We've seen that with kind of the zeolite products, new products out there.
Are there other ways to, you know, skin the cat?
I think it's going to be an interesting few years in calcium mobilization, but a lot of other things keeping up with milk production and the components that have.
So, thanks, Jeff!
Tom, thanks for joining us here again at the Real Science Exchange. What thoughts do you have for us?
Yeah, I just, you know, I've got a huge amount of respect for the work that Laura and her group have done to help us unravel some of these things.
Again, Jess McArt on the epidemiological applied calcium treatment side, right?
Other groups have been in the mix too on the nutrition side.
Laura, just a quick comment.
My group doesn't often complain about sampling schedules, but if they ever do, I'm just going to point to one of your papers.
Because from a rigorous and frequency of sampling standpoint, so...
But no, just fantastic work, and a privilege just to come on today.
So, thanks, Scott, thanks, Laura, and Jeff!
Yeah, thanks, Tom!
Laura, any final words for us?
I just want to thank you for the opportunity to talk about it.
I know I'm a pretty intense physiologist, but I think I was trained to be curious, and that lactation is a cycle.
We have to really think about that and how the mammary gland is directing the show.
I like to approach things from that way, but I've been fortunate to learn from a lot of cool people and had a lot of great support.
It's been fun as a basic scientist to cross paths with epidemiologists and see your work really have an impact.
That's been a lot of fun in getting to know Jess and Tom and Sabina Mann too.
We've done some cool things together, and Tom, I buy them a lot of pizza and cake and throw a lot of parties.
I often go out there and sleep at the barn with them if they let me.
But I've been really lucky with an amazing group of scientists over the years, so they almost always are game, which is a surprise because the sampling schedules are brutal.
One other thing I would add—I was thinking about—is, you know, the last few years we've talked a lot about the longevity of the cow and how many lactations are we getting.
I think what Laura is doing is going to be key in that, aside from just, you know, milk fever and subclinical milk fevers.
Just, yeah, you know, it's going to be key in that.
Yes, great point!
So, Laura, I'm not an intense physiologist, and admittedly this topic was a bit intimidating to me, but I've got to tell you it's been enjoyable and understandable for me.
I appreciate the two co-hosts here, Tom and Jeff, for coming along and helping out.
This has been a great podcast. I've enjoyed it, and I want to thank you guys for spending time with us and lending your expertise and knowledge to the industry.
To our loyal listeners, as always, we really appreciate the fact that you come here and spend time with us.
We hope you learned something, we hope you had some fun, and we hope to see you next time here at Real Science Exchange, where it's always happy hour and you're always among friends.
We'd love to hear your comments or ideas for topics and guests, so please reach out via email at marketing@balm.com with any suggestions, and we'll work hard to add them to the schedule.
Don't forget to leave a five-star rating on your way out!
You can request your Real Science Exchange t-shirt in just a few easy steps. Just like or subscribe to the Real Science Exchange and send us a screenshot along with your address and t-shirt size to a.m.marketing@balm.com.
Balchem's Real Science Lecture Series of webinars takes place on the first Tuesday of every month with the top research and nutrition topics that will impact your business.
We also include small ruminant, monogastric, and companion animal focus topics throughout the year.
Visit balm.com/real-science to see the upcoming topics and to register for future webinars.
You can also access past webinars and search for the topics most important to you.
[Music]