Guests: Dr. Bill Weiss, The Ohio State University; Dr. Jesse Goff, Iowa State University Today’s podcast is our January installment of the Journal Club, styled after the traditional journal clubs at universities across the country and around the world. Today we’re a closer look at some of the newest research published in the Journal of Dairy Science. Article 1: https://bit.ly/3zCBdIA
Guests: Dr. Bill Weiss, The Ohio State University; Dr. Jesse Goff, Iowa State University
Co-host: Dr. Clay Zimmerman, Balchem
Today’s podcast is our January installment of the Journal Club, styled after the traditional journal clubs at universities across the country and around the world. Today we’re a closer look at some of the newest research published in the Journal of Dairy Science.
Article 1: https://bit.ly/3zCBdIA
Dr. Jesse Goff, in summarizing a paper from the Netherlands, stated animals on a low phosphorus diet had lower blood phosphorus than the other animals, which isn’t unexpected. But the animal's calcium concentration had improved on a lower phosphorus diet. (5:53)
Dr. Bill Weiss emphasized a two to one phosphorus ratio isn’t always correct. The important thing is to meet the NRC requirements for both phosphorus and calcium. (11:38)
Dr. Jesse Goff warned that even if you think you are feeding a low phosphorus diet if you are using byproducts - such as soybean meal, canola meal and wet brewers - it can all bring in a lot of phosphorus. You need to be wary of that in the diet. (17:20)
Dr. Bill Weiss mentioned you should be in a slightly deficient diet postpartum and not meet the NRC requirements. Dr. Jesse Goff added that a postpartum cow would be pulling phosphorus and calcium out of her bones, needing less in her diet. (29:26)
Article 2: https://bit.ly/33hKjyI
Dr. Jesse Goff and Dr. Bill Weiss summarized the second article, which covered a study with an even lower phosphorus diet than the first article. This study promotes a low phosphorus diet as a way to control hypocalcemia. (36:49)
Dr. Bill Weiss mentioned that based on these papers, he thinks the low phosphorus diets in the pre-fresh and in the far-off should not worry as much so you can have some cost-savings in your feed.
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Scott Sorrell (00:07):
Good evening everyone and welcome to the Real Science Exchange. The pub we're leading scientists and industry professionals meet over a few drinks to discuss the latest ideas and trends in animal nutrition. The Real Science Exchange is brought to you by Balchem animal nutrition and health. Visit balchem.com to see how Balchem’s line of encapsulated nutrients and chelated minerals can impact your bottom line. Hi, I'm Scott Sorrell, one of your hosts at the real science exchange. And tonight we're kicking off the new year with our January installment of the journal club. Styled after the traditional journal convened at universities across the country and around the world, we'll take a closer look at some of the newest research published in leading scientific journals. This segment is scheduled to air once a month. We will welcome Dr. Bill Weiss America's professor from the Ohio state university to the pub where we'll discuss the selected papers that were recently published to gain additional insight and liven up the discussion. We'll also invite the authors to join us whenever possible. Tonight's discussion focuses on phosphorus in the fresh and transition cow diets, Clay Zimerman my steady co-host takes it away.
Dr. Clay Zimmerman (01:17):
Bill, Welcome back to the exchange, and thank you for taking on this role for our journal club. You're becoming quite a regular here at the exchange. And we are so thankful to be going forward with this monthly special in 2022. What’s in your glass for tonight's conversation and who did you bring to the pub with you?
Dr. Bill Weiss (01:37):
Actually, it's just water in my, my glass today.
Dr. Clay Zimmerman (02:11):
So welcome back to the exchange. Dr. Goff. What, what is your drink? Our choice for you is for cold January evenings.
Dr. Jesse Goff (02:19):
I'm as bad as Bill, I'm drinking water and I decided to forgo the diet Pepsi because when we're talking about phosphorus, this is another issue for humans too.
Dr. Clay Zimmerman (02:31):
Oh, that's a good point. That's a good point. Well, our first paper for this evening is the effects of dietary phosphorus concentration during the transition period on plasma calcium concentrations, feed intake, and milk production in dairy cows. And it's by Kanthal Eddal from the Netherlands,from Utrecht University in Wageningen. And it appeared in the November issue of the journal of dairy science. So the link for this paper will be in the show notes for our listeners, but before we dive in, what I'm drinking tonight is Dave and Danny's hard apple cider from Kansas. So bill now let's talk about phosphorus. And why did you choose this paper?
Dr. Bill Weiss (03:21):
Well, one is, you know, hypocalcemia is still an issue we've learned a lot and I still get lots of calls on, on problems and, and phosphorus, I think is kind of an overlooked nutrient with respect to hypocalcemia. And there's been a series of papers. The other paper we're gonna talk about is also is just out, but in the last few years, there's been a series of papers highlighting the importance of dietary phosphorus in, preventing hypocalcemia. And that's kind of why I asked Dr. Goff because he's done actually a lot of work on this, and it's not quite reinventing what he did, but he's identified this as an issue as well.
Dr. Clay Zimmerman (04:08):
So let's, so we'll focus first on the paper from the Netherlands. So Jesse, would you like to give us an overview of this paper?
Dr. Jesse Goff (04:17):
Dr. Bill Weiss (05:51):
That's correct.
Dr. Jesse Goff (05:53):
And then they thought maybe they'd look for interactions between pre-calving, low phosphorus, and post-calving, low phosphorus. To me and maybe Bill, I should let you summarize too. But the bottom line was that the animals on the low phosphorus diet have substantially lower blood phosphorus than the other or cows not unexpected, but their blood calcium concentration has actually improved when they're on the lower phosphorus diets, particularly when the pre-calving low phosphorus diet, although there was a small effect of keeping that cow on a low phosphorus diet, even post-calving.
Dr. Bill Weiss (06:37):
I guess, you know, the thing in the new NRC, their low phosphorus would just meet the new requirements. So that, that was just almost I think the new requirements was 0.2 and they were at 0.22. So essentially feeding to the requirement reduced increased blood, calcium feeding, excess phosphorus, decreased blood, blood calcium. One question I used to get a lot from veterinarians is low phosphorus post-calving. We see we'd see this, and a lot of times I'd say it's, maybe it's highly related to the intake. They're not eating phosphorus. So these were quite low, I mean.
Dr. Jesse Goff (07:19):
Yeah,
Dr. Bill Weiss (07:20):
You know, one of 'em dropped as low as 0.8 for a day seven. Is that an issue or are these cows designed to handle these short-term? It bounced back within a couple of weeks to normal, but for a week or two, it was really low on the low-cost diet.
Dr. Jesse Goff (07:38):
Well, so I'm a veterinarian
Dr. Bill Weiss (07:42):
We won't hold that against.
Dr. Jesse Goff (07:45):
We're taught to take blood samples and make pronouncements, right? And unfortunately, a lot of most cows actually will have a small degree of hypo phos EMIA when they Cal part of that's a reaction to the low blood calcium that almost all cows have not enough to cause milk fever, but it's low and unfortunately what that does is it turns on parathyroid hormone, which causes a salivary gland to kick out phosphorus into the saliva and if a cow has any kind of hypocalcemia, the ability of the phosphorus to move from the rumen to the small intestine is gonna be inhibited. And primarily phosphorus is absorbed from the small intestine, not the rumen And so at we often see this low blood phosphorus in a fresh cow as a result of parathyroid hormone reaction. Is it enough to worry about? I'm gonna say no, but you do have this thing called the hypophosphatemic downer cow. And as you suggested in this paper when they fed the low phosphorous diet during lactation, they actually had a few cows and this average was at seven days, was down at 2.17 milligrams per deciliter. That's really considered very low, but the hypophosphatemic downer cows we wouldn't see go down until they were down around 1.0 milligrams per deciliter. So substantially lower than even what they saw here. And as you said, they start bouncing back fairly quickly. Once they put a little more phosphorus back into their diet.
Dr. Bill Weiss (09:41):
So then you, you wouldn’t if these, these low phosphorus, which were, were again met requirements, they, we call 'em low phosphorus, but they would essentially meet the new NRC requirements. Aren't, aren't an issue if just because of low phosphorus, the benefit and calcium would over overcome any issues with there, be greater, a bigger advantage than these lower, lower blood phosphorus.
Dr. Jesse Goff (10:06):
Yeah. And I think yes, particularly in the precal diet, that low phosphorus issue really isn't something I'd worry about. And in fact, another line of evidence Barb Barton did one of the original papers showing that phosphorus, feeding to a cow inhibited the production of 125 vitamin D and caused the cows to get milk fever. They were feeding somewhere near an area of 80 grams of phosphorus per day to those cows. And, and like 90% of them got milk fever
Dr. Bill Weiss (11:38):
You know, another issue is, you know, with d-cad there, we tend to feed high calcium diets. And again, this old two to one phosphorus, you had to feed two to one. Yep. And so if they were at 1% calcium, a lot of people were feeding 0.4% phosphorus just because of that. You know, as you said, that ratio really doesn't mean much and you meet the requirements of both and there it's, approximately two to one, but that doesn't mean it's, that's what you need. You just need to meet the requirements.
Dr. Jesse Goff (12:10):
Well, and out in the field, I, it's not an experiment because I've never done the experiment, but I run into out the field enough where there's certainly still a, a thought that to make a low d-cad diet work, you have to have very high calcium in the diet. Yep. And I'll run into diets out in the field that are 1.7, 1.8% calcium. And unfortunately, I think they've also adopted the idea that the ratio might need to be higher. So you see above 0.4%.
Dr. Bill Weiss (12:42):
I do. I see a lot of that too.
Dr. Jesse Goff (12:43):
Phosphor too. And I think to some extent that undoes the good of the low d-cad diet, another proof of the pudding that that phosphor keeping blood phosphorus above a certain level is critical is the diets that they've been using, the calcium binder, the Exilite Zeolite the product can work quite well under some conditions. But if you look, those cows have extremely low blood phosphorus levels and it may be that that's part of its mechanism of action is to actually bind, phosphorus some similar to what's being done when you feed a very low phosphorus diet.
Dr. Clay Zimmerman (13:28):
So these were actually pre-calving were, were high decad diets, right? They were 300.
Dr. Jesse Goff (13:38):
Yeah. The Dutch paper was plus 300. The other paper is a little more moderate plus 50 or so.
Dr. Bill Weiss (13:46):
Yeah, this, this main, the paper discussed in mostly now was I think they were using the low calcium ignored D-cad. They fed low calcium, but I think what 0.35 or something? Calcium.
Dr. Clay Zimmerman (14:00):
It was 0.36. So then, yeah. So, for the high phosphorus, dry cow diet, the calcium-phosphorus were equal.
Dr. Jesse Goff (14:11):
Little take home from that. Okay. 0.36%. Calcium is pretty low calcium, but if you look at the results, how many cows got milk fever? There was a lot.
Dr. Bill Weiss (14:24):
About a third of the cow is very clinical.
Dr. Jesse Goff (14:27):
Yeah. Five outta 15. And then yeah. And, and so that tells you 0.36%. Calcium is not a low calcium diet. That's gonna prevent milk fever. It's you have to get much lower than that. And that's, where the Zeolite type binders. When they work properly, they bind up enough calcium to give it the equivalent of something, say a 0.1%, 0.15% calcium diet, maybe, but it has to be much lower than not to effectively prevent milk fever.
Dr. Bill Weiss (15:02):
I might just add the new there. This, you, I punched these cows into the new model and its calcium requirement was a little bit at 0.29%, which you're saying still may not be enough, but these were, were not based on new NRC. These cows were not de even marginally deficient in calcium. They still were slightly excess.
Dr. Jesse Goff (15:22):
Well, and, and then so if I fed 0.29, should I expect milk fever to go away? No, I'm still at the requirement. And how, how far below the requirements we have to get to get, you know, substantial turn on of all those systems. If you look at those old papers Howard Green did one of the good ones Rich Goings. There were, there were a number of groups you guys at Ohio state were doing some of that the old HS and Conrad type papers. They had to get calcium extremely low to make that work something on the order of fewer than 15 grams a day being fed was really low to make it work effectively.
Dr. Clay Zimmerman (16:05):
How can, how can you feed that in a practical diet?
Dr. Jesse Goff (16:09):
You, screw up a lot of other things.
Dr. Bill Weiss (16:13):
Yeah. It's, it's almost impossible for in the Midwest to get a diet, even at 0.25%. Calcium is almost impossible.
Dr. Clay Zimmerman (16:21):
Yeah. What about you know, this 0.22% phosphorus. I mean, so they were, they were not adding any inorganic, no phosphorus to this. Can, how achievable is that with, with a typical diet?
Dr. Bill Weiss (16:37):
It's, you know, part of the problem with this you know, byproducts tend to be high and they're cheap and they're high in phosphorous. So people tend to feed 'em and that's another reason I think we do see relatively high phosphorous, dry cow diets. You could, without at work at, with the feeds we had available in Ohio, I could get in, in the low twenties, low point twos. I couldn't get below 0.2, but I could get 0.22 0.23 three, but no byproducts at all. I couldn't feed any byproducts, no soy products, which you don't really need, but it was its fee. It's possible. It takes a little bit of formulation, but what's possible for the feeds we add. These would be straw-based diets. Of course.
Dr. Jesse Goff (17:20):
Yeah. The straw helps a lot, but as, as Bill suggested, and this is what I'm, what I'm running into the field quite often is canola meal extremely high in phosphorus compared to so soybean meal and soybean meals, no prize, it's still pretty high and there's gotta have some protein from somewhere. And then brewers, you know, you can get wet. Oh, we can get wet brewers in that's cheap and it's low and potassium. Well, yeah, it is. But it's so high in phosphorus. You gotta really be, be wary of that. Yeah.
Dr. Bill Weiss (17:53):
Distillers yeah.
Dr. Jesse Goff (17:56):
Issue. So, so be on the lookout for how you may think you've got a low phosphor diet when in fact, because you haven't added any d-cab or anything like that. Right. But be aware that there there's some byproducts that really bring in a lot. And I mean, a lot, I think canola's, what's close to 0.6% phosphor,
Dr. Bill Weiss (18:21):
But it's high proteins, oil seeds, in general, are high canola is higher than soy. I don't know where cottonseed meal fits in there, but it's probably
Dr. Jesse Goff (18:30):
High as well. It's pretty high too. So soybean of, of all the proteins soybean may be among the lower end of the, of the phosphor spectrum, if I recall. Right. But you can check that in the NRC
Dr. Clay Zimmerman (18:46):
So I did walk through the calculations on a grand basis for, for listeners, you know, that are looking at grams of calcium-phosphorus. If you, if you look at the last three weeks of the dry period and those dry matter intakes, they were averaging 48 grams of calcium on both diets, cuz they, you know, they had equal amounts of calcium in both dry cow diets, the high phosphorus diet was 48 grams. Yeah. Per cow, the low phosphorus is 28 grams a day.
Dr. Bill Weiss (19:20):
And you know, these cows were eating a lot. I think we're up around 14 kilograms, prepartum. Right. And that's another benefit with straws. You know we talk about concentrations, but straw can reduce intakes so that the grams per day are also reduced. So that's another big benefit of these straw-based diets, on mineral metabolism.
Dr. Clay Zimmerman (19:40):
So Jesse on it would be able to if people are looking at the paper it's on page 11652, it's the plasma inorganic phosphorus concentrations. So that, that really low, that 0.7% lower.
Dr. Jesse Goff (20:00):
It's seven yeah. 0.7 millimolar
Dr. Clay Zimmerman (20:03):
Millimolar
Dr. Jesse Goff (20:04):
That's which would be about 2.1 milligrams per deciliter.
Dr. Clay Zimmerman (20:08):
Okay. So that was those were the cows that were on the high phosphorus during the dry period and then the low phosphorus during lactation. Is that yeah. Is that level an issue that low level?
Dr. Jesse Goff (20:21):
Well, as I said, we'll see cows drop, but, and that's a low drop, but the fact that they recovered quickly and they didn't report any issues. As I said, when we saw the clinical hypophosphatemic downer cows, they were usually somewhere around one milligram per deciliter, which would be .31 Millimolar
Dr. Bill Weiss (20:49):
And you know, in, in the real world, that combination won't happen very often. In other words, you're not gonna have the low it's easy to get high, high phosphorus postpartum. So right. The low, the low, low wasn't that bad. If they fed low prepartum, low postpartum, those blood-kept blood phosphorous really wasn't that bad. And they bounced back very quickly. How important, and this was kind of addressed. This was a, a, a non Decad diet. If this was Decad Jesse, how important do you think phosphorus is in, these types of diets in those types of diets?
Dr. Jesse Goff (21:22):
Well, I like I said, I, I don't know if anybody's done the experiment quite that way, but out in the field, we're running into situations where the d-cad is quite low. But they keep the phosphorus high. Now, often that's in conjunction with a high calcium diet too, but we've seen that they're still not preventing all these milk fevers. They're still having breakthroughs more than just a few breakthroughs and the cows aren't doing that well, how it's complicated because some of these cows aren't eating either because of all the, all the calcium and all the anions being added. So it's a little complicated by that, but I'm convinced that if we, and get the phosphorus out those high or high anion diets as well were better off,
Dr. Bill Weiss (22:15):
I just, is there, is there any evidence or data saying that d-cad would affect phosphorus requirements? I'm not aware of it?
Dr. Jesse Goff (22:22):
No. I can't, I can't think of any, but, but here's a, here's a good one.
Dr. Jesse Goff (23:10):
But apparently, that phosphorus level got so high that they induced a lot of cows to get milk fever. Okay. So that's, you know, it doesn't be tempted by the thought that it's an acidifying acid to use it for prevention of milk fever.
So that, that was never published, Jesse?
it's in the abstract, you can still probably find the abstract let's was that the year it was in Oregon might have been the year. Oh, okay. It's a long time ago back in the 1990s.
Dr. Bill Weiss (23:48):
Back in the nineties.
Dr. Jesse Goff (23:50):
Remember that stuff.
Dr. Bill Weiss (23:54):
So I mean, that would, if, if no reason to think D-cad affects phosphorus and I, I agree. I don't think phosphorus requirement, then this paper would say feed to require, then you'd be okay. Which would be again around that 0.2% level. Yeah. And even with d-cad would be where people probably should be.
Dr. Jesse Goff (24:14):
I think so. And, and your problem is that it's very rare to find a practical diet where you're feeding enough protein and another thing that you're going to, you're gonna be bouncing too hard against that requirement. Yeah. You're usually your problem is trying to get below 0.3%.
Dr. Bill Weiss (24:34):
I said, we, we could, with our point below 0.25 I didn't have much trouble below 0.2. It would've taken some special ingredients. So,
Dr. Jesse Goff (24:44):
So how much straw are you've feeding bill?
Dr. Bill Weiss (24:46):
It would be about 40% of the diet and corn silage. And then not much else. I mean, there'd be a little corn grain, very little. We would, these proteins, a little bit of supplemental protein, no byproducts. And I'd be probably right at about 12% protein. So no the high protein diets.
Dr. Jesse Goff (25:08):
And now here's the next question. Are you ready? Cause I run you you run into it too. I'm sure. Well, I got heifers in there too.
Dr. Bill Weiss (25:18):
So yeah. And this, we should point out these, this paper was just multi paris cows. So, but yeah, if you got, then you start having to feed some, some protein. If you got heifers in there more protein, 14%, then it gets harder. I still think it, you can get it around 0.25 You don't have to be at 0.3. You can still get it at 0.25 with some select ingredients, but it's, it's more difficult.
Dr. Jesse Goff (25:45):
Just don't get above 0.4 that's where we're really seeing the issues show up. And you know, it's it many years ago, there's, there's another paper it's in the journal animal science. Our lab did all these experiments in swine too. And we showed that as dietary phosphorus increased this is George angstrom and Travis as dietary phosphorus, increased the activity of the renal one alpha Hydroxlace that makes 1 25 vitamin D decreased linearly so it, it was a, it was a strong relationship very linear. So getting phosphorus as low as you can remove that inhibition of the one Hydroxlace
Dr. Bill Weiss (26:40):
And this another paper we're not gonna discuss where they fed very low phosphorous and clearly even probably deficient phosphorous di prepartum. They actually got an increase in 125 vitamin D
Dr. Jesse Goff (26:53):
Well, that's not been universal though. And the second paper.
Dr. Bill Weiss (26:58):
The second paper didn't define that, but one, one of them did.
Dr. Jesse Goff (27:00):
So some do to back in the early eighties, he couldn't see a rise in 125 either, but they postulated perhaps there was a, a better receptor for the 125 vitamin D, but that was conjecture. They really had no idea.
Dr. Bill Weiss (27:20):
One, one other thing that again, with the new N see, the this is postpartum now the phosphorus requirements obviously includes milk phosphorus and milk phosphorus now is predicted based on milk protein. There is a good correlation and these, you know, fresh, if you have a fresh cow group, these got cows of high milk protein, which if you punch that into the new model, that's gonna give you high, high milk phosphorus and increase the phosphorus requirement above what, what I said would be. Yep. So that's could, if you, again, have just a fresh group that could be an issue with, you know, you may lose some of the benefits of the low phosphorus prepartum diet. If you meet the requirements, OPH OS partum. So that's something people might have to think about is maybe not going overboard. IP does have a French cow diet on Bosphorus.
Dr. Jesse Goff (28:14):
Yeah. And I, I think when you start looking at this too, the calciums also higher those first few weeks, it goes along with that protein being higher, I'm not so worried about adjusting dietary phosphorus. I, if I was, if I was working today and trying to figure stuff out, I'd wanna know if we get a benefit to adding more calcium to that fresh cow diet mm-hmm
Dr. Bill Weiss (28:43):
And keep phosphorous still kind of low, basically in the fresh group.
Dr. Jesse Goff (28:48):
I'd meet, I'd meet the requirement, but now you're really running into the problem. This fresh cow needs energy. Yeah, exactly. And, and you're gonna bring in phosphorus. Yeah. Pretty much with whatever energy source you bring in. Yeah.
Dr. Clay Zimmerman (29:03):
So Bill, how in, in the lactating diet, how did that low phosphorus diet? How, how, how close is that to the NRC,
Dr. Bill Weiss (29:11):
The new NRC? Again, I used, what I did was, as they went through top to six or eight weeks. I can't remember exactly. And I, I did the first three weeks and then the rest. Yeah.
Dr. Clay Zimmerman (29:25):
They went through eight
Dr. Bill Weiss (29:26):
Weeks. Yeah. Eight weeks. And then, then later in that group, say the last four weeks of the eight-week period, they would've needed 0.4% phosphorus to meet requirements the first four weeks 0.3, six. So roughly around 0.3, 8% for that thing. So, their high phosphorous diet met the requirements. And, and so they were, they'd say, you know, when you look at everything in total, you actually should be a slightly deficient diet postpartum, not, you don't want to even meet the requirements. Postpartum
Dr. Jesse Goff (30:00):
Re my thought that cow is gonna be pulling a lot of calcium out of her bones. Yeah. So if she pulls calcium out of her bones, she's also pulling out phosphorus and we've often thought that if you fed an adequate phosphorus diet, you see all that phosphorus show up in their urine, they get rid of it with it, what they don't need. So maybe you're not doing a soap, maybe their requirement for dietary phosphorus isn't as high as you think because they're automatically gonna pull some outta their bones.
Dr. Bill Weiss (30:29):
And there's none of that's included in the model. No mineral is included at all. It's too, too difficult. And you look at the blood phosphorus is out, out in lactation and the low, low phosphorus is, are just falling. I mean, there's no evidence at all that there's a deficiency based on blood levels.
Dr. Clay Zimmerman (30:50):
Bill the, so the calcium levels during the, in the lactating diet were like 0.6, 1%. Are those, are those adequate with the new
Dr. Bill Weiss (31:00):
NRC? I didn't look, I didn't break that down into the, you know, the early part of the experiment, the final, I just took the averages and the using. And I didn't adjust a lot of them, the availability coefficients. I kind of winged it. It would be a little bit lower than the requirement, just slightly, but very close. Okay.
Dr. Jesse Goff (31:19):
Very close. I, I, I was struck by that too clay. I thought, why are they going so close to a deficient calcium diet and lactation?
Dr. Bill Weiss (31:28):
Yeah. To me, there'd be, you know, with, and that's, everything is for an average cow. So, you know, you want to be above the average a little bit here. So that likely there'd be a lot of cows that would've been at least marginally deficient in calcium him in that, in those diets, in those, in that experiment, you should mention, you know, for, they did a lot of production measures. There was absolutely no effect of treatment, on intake or production. So that's not an issue here on low fo this, these marginal phosphorous diets had no adverse effects, post part.
Dr. Clay Zimmerman (32:06):
So would your, so, so based on, on the findings of this study during the dry period, would, would, would you supplement any phosphorus to dry cows?
Dr. Bill Weiss (32:17):
No, I would not. And I, I,
Dr. Jesse Goff (32:20):
No. No. Why spend the money? Yeah. Right. It's not gonna do any good for him. Probably hurt you. Yeah.
Dr. Bill Weiss (32:29):
And I'd also really limit the buy these high, high, high corn byproducts, soy halls are also high in phosphorous. So I'd really, they're cheap and they're tempted to use, but milk fever is an expensive problem. So, I would really limit those as well.
Dr. Jesse Goff (32:45):
You think soy Hals are that high in
Dr. Bill Weiss (32:47):
Phosphorus too. They're high enough. So,
Dr. Jesse Goff (32:49):
Oh, I didn't know that I thought I
Dr. Bill Weiss (32:53):
I'd have to look. I used to have almost all these numbered memory. I, no,
Dr. Jesse Goff (33:00):
Dr. Bill Weiss (33:16):
And it's, you know, it is, people need to, to think of, you know, the price of feed versus the price of hypocalcemia and usually, a little spend, a little more on the feed will be still a profitable thing compared to hypocalcemia. Yeah.
Dr. Jesse Goff (33:32):
Yep. So it'll be interesting. The next question is, you know, there are these people that are feeding one group, dry cow out diets, how low in phosphorus could you go without doing some harm over a long period of time? My guess is it's not gonna bother 'em too much. I keep thinking back to the old woo and Saturn papers where they fed those really low phosphorus diets for two or three years in a row. And only by the third year, did they start seeing some, some small decrease in, in mineralization of those bones, but of course, the cows were getting older too. Exactly. So it's hard to say that that even had any, any detrimental effect on those cows were,
Dr. Bill Weiss (34:18):
Were those tights in the, they were in the loop point threes,
Dr. Jesse Goff (34:21):
I think, oh, I think they even got the, they were three, two. Yeah.
Dr. Bill Weiss (34:26):
That for that experiment, there was another study. I can't from Europe, I think, but they got down to the 0.2 and they, they, by the second lactation, those cows were in trouble. The bones were shown. Yeah. They had to stop that, that treatment. But again, it was very much below requirements and it took a year to see any effect. And it, this, you know, this study here, they fed this low phosphorus in the dry period for six weeks. So that's almost a full, you know, yeah. Most a full one. Right. So I don't think there's any evidence that there's a-gonna be a problem with low phosphorus.
Dr. Jesse Goff (35:00):
Well, and one of the things a remark about is that the, well, certainly the second paper, which we didn't talk about much, there wasn't a rise in the blood, 1 25 vitamin D, which is not the universal finding of all these low phosphorus papers, but they didn't see a rise in 1 25. So they assumed that the bone was more to the mm-hmm,
Dr. Clay Zimmerman (36:04):
So Jesse, we can, we can transition to that second paper now. So I'll, I'll just introduce it here. It's an article that's currently impressed in the journal, dairy science it's called the effects of restricted dietary phosphorous supply to dry cows on para parti calcium standard. And it's by way at all out of Germany. Mm-Hmm
Dr. Bill Weiss (36:49):
This one again was the high and low phosphor. This was a very low phosphorous diet down to 0.1, 5% so lower than, than what the one we just talked about. The control was 0.3. So excess versus a deficient diet, or at least marginally deficient. This one had a, a, it wasn't a negative Decca, but the Decca was about 50. So they had some, some Anon in it, but it was not a negative and calciums were around 0.7. So this would be, I think, a, a mild Decca type diet and, and this one had fewer cows. So they're just looking more at metabolic measures. The last one had, you know, more cows per treatment, cuz they were looking at production and some clinical things. And, and may basically what they found is that the low phosphorus in enhanced blood calcium similar to what, what this other paper found they only fed these low phosphorus diets for four weeks prepartum. And, and they did, like Jesse was saying in this paper, they did not see a difference in 1 25, this same group with a, a little bit different protocol did find an elevated 1 25 concentration, but they did find a marker, which I can't remember what it was a bone marker. That indicates mobilization of bone was increased, with the low phosphorus dye. So this again supports low phosphorous enhancing calcium metabolism or calcium's data is postpartum. Yeah,
Dr. Jesse Goff (38:28):
No that's pretty much a good summary. The this group has been pretty active in trying to promote this low phosphorus as a way to help control hypocalcemia. They, they have used an Eliza assay to measure the vitamin D and huh, I gotta tell you that we've tried that and it's, it's not as good is if you do it by the other methods, which right now it's LC mass spec. And I'm not sure why the animals don't respond as well as the humans do in those, in those Eliza assays. But they always seem to be off by a bit. So IR, regardless of that, that's just a, a technical thing to be aware of the cross labs. The protein you're looking for in bone is supposed to be a measure of astic resorption. So if that goes, that goes up here in good shape.
Dr. Bill Weiss (39:30):
I'm not, I'm not familiar with that, with that cross labs.
Dr. Jesse Goff (39:34):
Well, Annette leaves, a gang led the charge on this. Annette's a researcher in Zurich, Switzerland. And she looked at a lot of different portions of the collagen molecules and bone. So theoretically, when an osteo class is activated, it, choose up the collagen and spits out these fragments of collagen into the blood. And so, and also shows up in the urine. So you can measure these fragments. Some of the fragments are more associated with bone formation than they are with bone resorption. So you have to separate those out. And a net shows that this one there its CTX is their abbreviation. It's one portion of the collagen molecules only seen during bone resorption. So it's, it seems to be, it's much more sensitive. You may be familiar with Clay when we were younger guys hide doxy proline was what everybody measured, right, right. Which is, a strange little amino acid or a proline that's been modified post-translationally to be put into collagen. And when that showed up in the blood, we assumed it meant more bone resorption, but at this CTX are many problems. They double the sensitivity of the hydroxyproline. So it's, it's the better way to measure bone resorption mm-hmm
Dr. Bill Weiss (41:08):
And again, this, on this one where they were now, again, based on new NRC, these diets were deficient in phosphorus, both grams and percents and, and their blood phosphorus inorganic, phosphorus, prepartum were around one millimolar. And, and you're saying that's not an issue. So even with deficient diets, they still, the blood phosphorus was still is okay.
Dr. Jesse Goff (41:33):
Well, it would be an issue if you're a veterinarian
Dr. Bill Weiss (42:16):
So again, the benefits on calcium would be, would justify this, this lower blood phosphorus, which is, you know, based on what they're reporting didn't cause any clinical issues and either paper.
Dr. Jesse Goff (42:31):
Yeah. And, and you know, Walter Grinberg has done a number of papers now and they all come out the same. They, create this low phosphorus issue, milk fever, and hypocalcemia are greatly diminished. It's pretty hard to argue against this. And now you've got two new verses that just came out in the last couple of months, say the same thing. It's a, it's a story. That's got legs now. There's, there's not, we've probably had no idea why Barb Barton and Tom Cura had these problems with high dietary phosphorus. But as time goes on, we've learned a lot more about these mechanisms of action, this little fibroblast growth factor, 23, and all those kinds of things. The problem is nobody's been able to measure that in a cow yet. Mm-Hmm
Dr. Clay Zimmerman (43:42):
So Jesse, if I'm if I'm feeding a feeding, a herd and the veterinarian is testing blood samples,
Dr. Jesse Goff (43:59):
Tell 'em, give 'em a beer and tell 'em to walk away.
Dr. Clay Zimmerman (45:34):
So, so tip, so, so how should, how should these cows be treated normally, you know, with IV, what, what should, what should they be Ivied
Dr. Jesse Goff (45:42):
With? Well, first off, prevent milk fever and you hardly ever see these cows, right? I mean, I, I, I gotta tell you since before the, before the DEC diets became popular I would get samples in from farmers and veterinarians all over the country, actually not all over the country. It was always north of the Mason Dixon line. And I'd get these cows in that had hypo EMIA and they'd be down. They weren't responding to calcium. They weren't responding to the calcium solutions that supposedly had phosphor in them that were being sold in those days. And that's when we started looking into it and said, well, if you're gonna treat 'em, it has to be phosphate, PO four, not PO two, two or P oh three, which is what was in the bottles. Okay. And so that, that went, that was helpful. But shortly after we started doing the Decca diets and they became pretty popular, I mean, there's a lot of folks using that or some other means of preventing milk fever. I gotta tell you, I, I, it's been probably two or three years since I saw how hypophosphatemic downer count or had samples sent into me to look at it. It's kind of gone away.
Dr. Bill Weiss (47:03):
I can think of, one practical question. That is again with we, we talked about the issues of, of these low getting low phosphorous diets. So what is, is it low phosphorous just in the pre fresh, adequate, or do you think it has to be longer and neither of these papers addresses this, is it gonna be speculation, but,
Dr. Jesse Goff (47:23):
Well, I think if you look at the German paper Greenberg's paper, they only fed it pre-cal for
Dr. Bill Weiss (47:30):
Four weeks. It was
Dr. Jesse Goff (47:31):
Four weeks. So, and then Tom Cura, Barb Bart, and all those papers, they went back to a normal phosphorus diet or what was normal at the time. And, and it seemed to work fairly well, but, again, a low phosphorus diet in and of itself is now not going to prevent milk fever. No, no, it's just one of those factors that may cause milk fever. If you let phosphorus get outta whack too much.
Dr. Bill Weiss (47:58):
Well, I'm thinking, you know, if they do the other stuff, the Decca and everything else, are they just feed low phosphorus in the pre fresh. Is that enough? Or do they have to watch phosphorus and the far off as well?
Dr. Jesse Goff (48:12):
Oh, I don't think the far off, I, I don't think the far off matters too much. Okay. For this. Okay.
Dr. Bill Weiss (48:21):
Do you, no, I, I don't know. I would, from what, from papers, I, these papers, I would say no. And what we know about other things on how long these things have to be around to have an effect. I don't see why it would matter. And again, that way you could save somebody with using these cheaper products in the far offs and then concentrate on, on the pre fresh on getting these low, low phosphorus in addition to what the other stuff we talked about. So, that might be an easier sell-to-on, on economics.
Dr. Clay Zimmerman (48:53):
Any other take-homes from this second paper outta Germany?
Dr. Bill Weiss (49:00):
No, I said it just, it more mechanist. It talks about some other measurements, but it is supportive. And again, it, it may, these were deficient diets by our standards and these cows still didn't drop dead. So short-term phosphorous, marginal deficiencies. I think they can handle it because I, I think Jesse was saying, they're almost designed that, that way. So, and they, they it'd be very difficult to get diets that low in, in us, but they were quite low and they didn't cause any actually was beneficial compared to the higher phosphorus diets.
Dr. Clay Zimmerman (49:36):
So, on a practical basis, do you actually think that could we have a phosphorus, efficient diet for dry cows in us?
Dr. Bill Weiss (49:47):
It'd be pretty hard. It would be hard. I'm sure you can. There's you seem impossible. You never see never, but it would be very, very difficult.
Dr. Jesse Goff (49:56):
Well, and if we think about phosphorus a, with a dairy cow, with the amount of fee they eat and, and things like that there's no reason any nutritionist should be looking at DCAL at all. Yeah, no. Any, any time of the life of a, of a cow, maybe a calf, a room pre ruminant calf, maybe, but not, not a cow. Yeah. I don't think they're not, not with corn being king around here. Yeah. Yeah.
Dr. Bill Weiss (50:25):
As I said, I'm sure there are a few diets where it's not true, but the vast majority of SU supplemental phosphorus really is not needed very often both prepartum and postpartum
Dr. Jesse Goff (50:37):
And it was expensive. Yeah.
Dr. Bill Weiss (50:39):
Yeah. And there's the environmental issues and everything else. And, and to me, it's just not, you know, if you need, you feed it, but in general, you don't need it. And I'll just say the new requirements we didn't go into this, but in general, the phosphorus requirements for lactating cows will be slightly lower, very Mar just marginally lower than what they were in 2001 just very marginally lower, but they will not be higher. So
Dr. Jesse Goff (51:09):
Well, I was gonna, I was gonna give you some grief bill. Are you ready for some grief? Sure, sure.
Dr. Bill Weiss (51:32):
Five or whatever, but they're lower. I know that.
Dr. Jesse Goff (51:35):
Yeah. And this Dutch paper though, it's 1.17 1.22 it's,
Dr. Bill Weiss (51:39):
But there's a lot, there's a lot. It's a mean, there was a lot of data that went into milk competition more than what went in 2001 I'll
Dr. Jesse Goff (51:50):
Just right. The good news is that you lowered the absorption coefficient. So you're ending up feeding, close to the same amount. Anyway,
Dr. Bill Weiss (51:59):
The calcium requirements. Again, the equations changed quite a bit, but they, at the end of the day, they're very, very similar to what they were in 2001
Dr. Jesse Goff (52:18):
And, and hats off to you for fixing magnesium. Yeah, because
Dr. Bill Weiss (52:23):
That was a lot worse. Well,
Dr. Jesse Goff (52:24):
Even when, even short within a year or two, after you, 2001 was released, it became very apparent to me out in the field that we probably had messed that up.
Dr. Bill Weiss (52:37):
Dr. Clay Zimmerman (52:55):
Any more, any other take-home points for this, for this for the German paper?
Dr. Jesse Goff (53:04):
No, I, I know Walter Greenberg a little bit, and every time we've gotten to get that, we talk about, who's gonna figure out how to make this assay for this fibroblast growth factor 23, and, and can anybody ever measure it? And Walter assures me, he is working on it, but he didn't have it yet, I guess.
Dr. Bill Weiss (54:14):
All, all those blood measures, none of 'em are with cows, you know, within a few days of Calvin. So what most of them are not
Dr. Jesse Goff (54:23):
What they're calling the normal range. Exactly.
Dr. Bill Weiss (54:25):
Yeah. It doesn't include, we don't know what the normal range for these where we do, but it's, or we might, but it's different than Cal three weeks in lactation. The normal range is different than one at two days in lactation. Yeah.
Dr. Jesse Goff (54:40):
Yep.
Dr. Clay Zimmerman (54:41):
Well, I just heard Kim announce the last call. So I wanna thank you both for joining us tonight. Bill, you picked a great set of papers here to start off 2022 with the journal club some, some nice practical application herewith, with phosphorus during the dry period. So with that, I wanna thank you both for help, helping to kick off our second year, the real science exchange, and the journal club for 2022. We're excited to be able to add this segment to our programming and look forward to the next round of paper. So thank you both.
Dr. Jesse Goff (55:23):
Thank you, clay. Good to see you again.
Scott Sorrell (55:26):
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