OPP with Dr. Rosie B

Join us for a discussion about the effects of Ovine Progressive Pneumonia (small ruminant lentivirus) on flock management and lamb raising with Dr. Roselle (Rosie) Busch from the University of California's Department of Agriculture and Natural Resources (UCANR). Dr. Busch is the California Sheep and Goat Veterinary Medicine Extension Specialist and her website can be found here: https://ucanr.edu/sites/sheepngoat/

In this episode we discuss identification of mastitis in pasture-raised sheep and the correlation between mastitis and OPP within a herd. We also discuss how this disease impacts lamb rearing, culling decisions, and intervention strategies on different types of operations ranging from large-scale extensive grazing outfits to small-scale intensively managed farms.

This month's paper is titled "Cross-Sectional Study Assessing Management Practices and Udder Health in California Sheep Flocks and Seroprevalence of Small Ruminant Lentivirus" and can be found here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11350894/

Dr. Busch also hosts her own podcast called "Sheep Stuff Ewe Should Know" with her friends (and skilled sheep producers) Dan Macon and Ryan Mahoney. Give them a listen here: https://open.spotify.com/show/0wu6MF1PIBbcwp9zrJCVqI

If you are interested in attending on-farm lambing school with Dr. Busch in California, follow this link to learn more about Camp Kaos: https://fibershed.org/event/live-lambing-class/

Fibershed is a national organization focused on building regional fiber systems to promote sustainable textile production and environmental health: https://fibershed.org/

If your company or organization would like to sponsor an episode or if you have questions about today's show, email Office@AASRP.org

Transcript

Sarah: 0:40

All right. Hello, and welcome to this month's Baas and Bleeds. Today we're going to be talking to Dr. Roselle Bush. Did I say that right?

Rosie: 0:50

Yeah, but I go by Rosie.

Sarah: 0:52

Okay. Well, we'll just call you Dr. Bush. That'll be easier. Um, Dr. Bush is a faculty member at the University of California, Davis, um, at the Vet School. So good to talk to you. How are you doing today?

Rosie: 1:05

I'm doing great. I'm excited to be here. Thanks for having me.

Sarah: 1:08

Yeah, I'm excited too. It's really excited as an East Coaster to talk to somebody about West Coast things because it's so different out here. But I grew up in California like we were talking about before, so my heart is still out there a lot. So, can you give us a little just a brief history about where you've been, how you got here? I love hearing all the different schools everybody has been to and the career path that they've been. So give us your backstory, your superhero backstory.

Rosie: 1:35

Yeah, mine might be different from a lot of folks, but I actually grew up in San Francisco in the city of, and I kind of always knew I was gonna leave the city. And I've I was always really infatuated and rode horses when I was younger, and so I was gonna be an equine vet. So my family who lived in Placerville, which is just a little to the east of Sacramento, they said, Well, you have to go to UC Davis, it's the vet school. So I went to UC Davis for animal science undergrad, and then I somehow magically got into the vet school and I studied large animal and really enjoyed working with livestock. And I kind of discovered that some of my favorite equine people were cattle people, and so it really kind of transitioned into when I graduated, I worked in mixed animal practice in Hollister, California for a year.

Sarah: 2:33

It's garlic capital, right?

Rosie: 2:35

Yes, yep. And amazing rural country that's only like 20 minutes away from San Jose. It was kind of amazing to me. Folks who lived in San Jose had no idea that these historic ranches that were established in the 1800s were still there. You know, I'd be preg checking, you'd kill hear elk bugling, and then the traffic is like just over the hill. It's just like so wild, just how those two things were just right next to each other. But yeah, it it was I graduated in 2009, so that was kind of when we had our big economic downturn. And so it was it was tough being in practice at that point. And so I actually went back to the university to do a large animal internal medicine residency in livestock, and then kind of I stayed on as faculty as a or not faculty, as a staff veterinarian in livestock medicine and surgery for three and a half years. And then from there I went to CDFA for the antimicrobial use and stewardship program because California decided to pass the law that affected everyone last year, where all antibiotics went from over-the-counter to prescription. We did that in 2018. So I helped kind of work on some stewardship principles and communicate with fets and producers about how that would impact them or really not impact them too much. And then in 2019, I started this job as this sheep and goat extension veterinarian. So I do extension, which is basically teaching, but outdoors and working with producers and private practitioners and just on sheep and goat things. And then I have a applied research program. So when we have questions that we don't have answers to, that's where we get to kind of do some work to figure out what's going on there.

Sarah: 4:26

That's fun. Well, the rest of the country is very thankful that California went through the whole antimicrobial thing first so you can advise the rest of us when it happened to us and tell us it's gonna be okay. It's not really appreciated that from all my California friends. Well, I've always thought being an extension agent is like the best of both worlds because you get to be out teaching and have boots on the ground, but you're also also kind of in academia with the ivory towers behind you, also.

Rosie: 4:57

So I get to have really smart friends, get to work with them, but also get like you said, I get to be out with a lot of really great producers, and yeah, it's I love it. It's great.

Sarah: 5:10

Yeah, and nobody calls you at 3 a.m., I bet. No, well, sometimes not at three.

Rosie: 5:15

I get plenty of calls on the weekend, but yeah, it's funny.

Sarah: 5:20

Um, okay, so today we're gonna be discussing a new paper, just came out this year, right? In the journal Animals, which is super legit. I looked it up. So good job. Uh so this paper is entitled Cross-sectional study assessment management practices and utter health in California sheep flocks and sero prevalence of small ruminant lentivirus. So that's long. So we'll get into it. Not that confusing, but the the title is a lot. Um like I said, this was published in the journal Animals. The paper basically is describing the results of a survey sent out to sheep producers to get a better idea about their mastitis prevalence and you know, maybe get some idea of kind of how different production styles you see more or less mastitis and what's affecting it. And then obviously a piece of it was the Lenti virus, which I know you guys specifically try not to use the term OPP in this paper, but I will absolutely slip and say it at some point.

Rosie: 6:22

So I I will say before submission, it was OPP everywhere because that's what we call it. But because it is a more international paper, they're like, we really do have to call it small ruminant lentivirus. I was like, okay, well, that makes sense. But I think at one point we did say, okay, we really do need to have one point in the paper where we say that, yeah, there's on like that third paragraph down, it says ovine progressive pneumonia is a clinical manifestation of small ruminant. And we were like, because we have to let our readers know that this is what we're talking about, not you know, for more of our lay audience. So right.

Sarah: 6:59

And so for any Go people listening, OPP is kind of the sheep version of CAE. So they're both lentivirus based, and they both have very similar symptoms with the hard bag, sore joints. I think the pneumonia thing, at least in my experience, is more sheep. I don't see that a ton in goats. Would you think that's true? Yeah, definitely. Okay. And the other thing I always see in goats, and I rarely see in sheep, is horrible diarrhea at the end. I don't know why.

Rosie: 7:28

I don't know if that is because the sheep are being called before that because of maybe the pneumonia. I don't know, but yeah, like wasting, they get really thin. Yeah. Um, and sheep, like in Australia, they call them tail enders because they're always at the back of the flock moving. So they have a really hard time keeping up with everyone.

Sarah: 7:47

Yeah, yeah. So a lot of wasting. And like I said, I see a lot of pets, so I see animals that culling is not happening until the very last second. So I might see a severity of the diseases more than they're in heavy production places. Okay, so what kind of was the driving force of this survey and how did you kind of get it out there?

Rosie: 8:09

Yeah. Well, when I started this position, a lot of the most common calls I would get were about how to raise orphan lambs, or they had orphan lambs that were doing so great while they were on milk, and then they weaned them, and then they all just started going downhill. So it was a lot of, you know, like educating them on an artificially raising lambs and kids, and you know, teaching them how to introduce solid foods before they wean them, and you know, like basically preparing the rumen. And I was like, gosh, why do we have so many orphan lambs? Like, what is happening here? And so I started looking into different resources on, you know, the abundance of orphan lambs, and it seems, you know, understandably pretty common in breeds that are like polypays, where they have litters basically, but that's not really the type of sheep that we have. You know, we have catatins and dorpers and really a lot of ramblet, kind of white face range sheep. And so it wasn't a lot of those really high fecundity breeds. So then it's really kind of got me thinking. And then one of my good friends was like, Do you think subclinical mastitis is an issue in sheep? And I was like, Well, I don't see why it why, you know, like we probably have a problem with subclinical mastitis, but I think it would be really good to, you know, get a better understanding of how important clinical mastitis and then OPP is in our populations. So that's kind of where this came from was just to have a baseline describe the problem and then kind of use that as a jumping off point.

Sarah: 9:52

So a key thing to remember with this as we go through is these are not sheep dairies. So they are not, nobody's touching their udder multiple times a day, nobody's measuring their milk output. So really looking at how the lambs are doing is how they know if they have mastitis, right? Or maybe if they're at the back of the flock, like you said, like they don't feel good, they're running a fever, you know, something like that. But really, it is like, why is this lamb so small? Why is this lamb look like it's starving?

Rosie: 10:22

Right. And part of that was or that this that was also in the survey is like, how are you identifying mastitis? Is it from land? You know, I think so. Survey design is like should be a PhD in and of itself, and it probably is, but probably is. And so we, you know, would ask questions like, what factors do you consider when diagnosing mastitis? And so a lot of the surveys came back with like, yeah, we look at all those things. It's like, okay. So we didn't gain as much information as we had hoped to on how they're diagnosing things, but that was part of it, yeah. Like lamb performance. Is it, you know, are they seeing visual things with the udder itself, like utter characteristics? Yeah, or are people actually trying to, you know, we had like a few people that actually strip out udders while they're in the lambing jugs. But not a lot of people are using lambing jugs, as we find out.

Sarah: 11:20

So you you went to the wool growers association, right, and you use their email list and sent out these and you got like 70 responses, right?

Rosie: 11:29

Yeah.

Sarah: 11:30

Okay, and then if you look at the paper and you can give us the numbers, there's definitely a spread in sizes of flocks. So some were over 500, some were relatively small, like in the hundreds, right?

Rosie: 11:44

Yeah.

Sarah: 11:46

So you have a swath of kind of different production sizes.

Rosie: 11:52

Yeah, and uh, it makes so we we also use we use the California Wool Growers Listserve, but we also used social media sites, so my own, which at the time was not very popular. So, but also Fiber Shed is a nonprofit organization in California, and they're now have a more of a global presence, but they disseminated the survey for us as well. And so I think that's where a lot of the less than 100 producers came in. And so it c it does kind of make sense that we have a bit of a more even spread, whereas you know, 90% of our producers are going to have smaller, like hobby flocks and things like that. But 90% of our sheep are owned by 10% of these larger producers. So we definitely overrepresent larger herd size in this survey just because of the the media using California wool growers. We had more of their attention, I think.

Sarah: 12:55

But yeah, so these are flocks that are raising sheep for meat, wool, and possibly babies for yeah, genetics, seed stock.

Rosie: 13:08

Yeah, yeah. Okay, okay.

Sarah: 13:10

Okay, so now we have the who. And so you really your questions were really focused on all things mastitis, but that definitely gets into a lot of production questions. Um so do you want to just kind of give us some of the big questions that you guys were really hoping to get some answers from and why those were important, maybe?

Rosie: 13:30

Yeah, so we were looking at, you know, basic understanding of their production system. So breeding management, if they were a fall lambing operation, which is actually pretty common with our commercial operations here, or a spring lambing operation. And in my mind, you have very different nutrient sources available to them. And I have heard things from producers like, well, if we're in a drought year, we tend to see more mastitis because they're not making as much milk and their lambs are going after their udders like crazy. And I was like, Oh, I wonder if we'll be able to see some of that. But I think because most of our larger operations are fall lambing, that that confounds for that kind of granularity. So, you know, just trying to become familiar with what type of operations they have, if they're more extensive or intensive, if we had, you know, lambs that are early weaning, so less than 90 days versus kind of a more traditional weaning age of over 90 days, and how, you know, if there's an assumption that early weaning might be more likely to have you go into mastitis because they're kind of at peak production at that time between 60 and 90 days. Yeah, so it was those were why we asked those questions. And and then yeah, we get into more like utter health questions, like what when are they looking at the udder? What types of things might they be looking for to help them determine if there's a problem with the udder? So if they're, you know, using palpation. Most of our respondents reported utter palpation as their most common way to detect abnormalities in the udder rather than actually the lamb that's failing to perform.

Sarah: 15:25

But why would they palpate an udder unless there was a reason? Like when I read that, I was like, yeah, but if the lamb, you're not just gonna walk up to every sheep and start palpating udders if everything's going fine.

Rosie: 15:37

So, you know, like when lambs and ewes are out in the pastures, if lambs are weak, then yes, they'll catch that you and they'll, you know, they'll first they'll catch the lamb, see if there's something wrong with it. But I've tried to work this into you also have to catch the you, make sure her udder's okay. But most often we're only bringing ewes and lambs in for you know, marking, which is when we tail dock and castrate and vaccinate, and they'll deworm ewes and bring them all in when they're about four, you know, two to four weeks of age. So in these larger flocks, every time they're gathered, lambs and ewes aren't necessarily together, and they don't necessarily know whose lamb is, you know, belongs to which you. And so a lot of the udder palpation that's happening on these ranches that are doing a good job of identifying ewes with mastitis, that's usually happening at like weaning. Um, so they'll, you know, kind of mark any u that has a bad udder, and she won't be kept around for breeding for the next year. Okay.

Sarah: 16:43

So they might have lopsided udders, one side dried up, something like that. So they could be cold for that. That makes sense. Let's see. For those of you that have never felt what a lentivirus udder feels like, the way I kind of teach it to students is it just feels wrong. Like, yeah, you know, it doesn't, it doesn't feel like a mastitic udder to me. It doesn't feel like an udder that's like engorged with milk. It feels completely different. It's like nothing else you felt. I mean, if I go see a small ruminant, you know, that they're worried about mastitis and like it literally takes five seconds of touching it, and you're like, yeah, that's a hard bag. So the lentivirus infection, if they are, you know, palpating utters, I would say most of these shepherds, shepherdesses know who has it.

Rosie: 17:36

Yeah, absolutely. Especially the ones that have been taught to do that as they're kind of practice at weaning, they're really good at palpating udders. Right. And it's interesting because I know who had what percentage, and I know that they're like the lower percentage of OPP in their flock, they're they're doing those practices. And so that's where it would be neat to kind of follow up and see as people started adopting these practices after realizing that their OPP percentage was higher than they wanted, they started adopting these kind of utter palpation techniques. And we went and taught them. We went out with the producers that had been doing this for generations, or you know, at least their entire time working with sheep and went out with them and had kind of just a you know, a big field day of palpating udders, and it was exactly that. Like, you know, what do you think about this one? And yeah, just all the consistencies and yeah.

Sarah: 18:38

That was kind of getting us off topic a little bit, but I just, you know, talking about palpating udders, like it's just, you know, the the lentivirus infection is just such a huge part of that.

Rosie: 18:49

Oh, I will add, we did ask questions about lambing management, mostly because I know that there's been a couple of other papers out of some awesome research groups up in Montana and Wyoming and even Nebraska, and they do all of their lambing through lambing sheds. And so a lot of their research is looking at environmental control to try to help prevent mastitis. And I was like, that's really cool, but it's not our system. And so if we have a mastitis problem despite pasture lambing systems, then there's something else going on here. And so that's kind of why we asked those questions to make sure we weren't missing that.

Sarah: 19:33

Okay, interesting. One thing I liked here in the on page three, it just kind of very quickly talked about the goals of the survey was to describe factors affecting utter health, lamb survival, and California sheep production. And the seven main categories was flock demographics, breeding management, pregnancy and lambing management, utter formation considerations, mastitis management, and lamb care. So, I mean, I feel like we've just scratched the surface of everything you guys talked about because it was so much like when they wean, how they wean, were animals separated, you know, were they, where did they land? Were they on pasture? Were they in a barn? Well, you're California, you don't have barns like we have barns, but you know, there was just a lot to this study. So I don't want, you know, people need to come read the paper to get the full the full aspect.

Rosie: 20:24

But as Yeah, and Rose D the f first author on the paper is Rose Digi Anton D Gian Antonio, and she did an amazing job on the statistics, but she should be the one to describe the She did an awesome job putting it. Talk to her about it.

Sarah: 20:42

But like, so kind of for the the lay person listening to this, you know, one thing that you have to think when you read these kind of surveys is it's really easy with statistics. Well, it's not easy, it's a thing with statistics to be like, you know, statistically, these two things are significant, you know, and you can easily, you know, one of my friends in graduate school did a paper sort of like this, and one of her findings was that heifers that have a hoof rot in this month of their pregnancy have twins, like just because A equals B and B equals C does not mean that A equals C, right? And so there's so many interesting things to pull out. And I think you guys did a really good job just explaining to the things that, you know, matter. Like this kind of management seems to give us these kind of results. Because I'm sure if we talk to the other rows, she definitely found some things like animals that went in jugs, you know, had blah blah blah. Like, because that's how statistics work.

Rosie: 21:42

I do have to say when she showed me that, where is it? It says greater than five percent of orphans was really closely associated with greater than five percent utter abnormalities. When I saw that, I was like, oh phew, good. That's that's what I would expect. And I'm really glad that that's how it came out.

Sarah: 22:01

Right, right. Yes.

Rosie: 22:03

Like, yeah, you do it.

Sarah: 22:05

If your utters are wrong, you're gonna have orphan lambs.

Rosie: 22:07

Yeah.

Sarah: 22:08

So it's great when common sense and statistics come together.

Rosie: 22:11

Yeah, and I know like a lot of our producers are like, why did you have to do the paper a paper to find that? It's like, no, no, no, there's more to it, but that is like, I'm just glad that, like you said, it's good that it that common sense and science like aligns.

Sarah: 22:26

That's always our goal. Okay, so let's jump to the the lentivirus testing. So you did get some of the flocks to to let you guys come out and test um for lentivirus. And so let's talk about that for a bit.

Rosie: 22:42

Yeah, so we had 20 farms that we visited, and you know, just so everyone understands some of the challenges we had. This survey was done in 2022, or we did the testing in 2022, and so we were still kind of reopening after all of the shutdown things. And so that was a little bit of a challenge, I think, to get some of the smaller operations to participate. But we had 20 folks participate. I pretended to auction off sampling sets at the California wool growers meeting. I was like, this is basically $400 worth of sampling. Like, so we had some people take those kits home and send back samples. And yeah, so we had a huge variation of folks that you know ranged in size between less than 100 to well over 500 sheep. And it was interesting. So studies done previously usually report what the flock level prevalence is. So, like of all the flocks we tested, how many of them had at least one animal with OPP? And a lot of the surveys done before are around like there was one, I think the NOM study was around 21%. And then the study they did in Wyoming was 45%. Ours was like 75%, which is really high. And it may have been a little bit falsely elevated because this study or this testing event was literally just for OPP, whereas like the NOM survey is for sheep health in general. So people who decided to participate in this may have, you know, been thinking, gosh, I think I have a problem with this. I want to know. So we may have selected for more OPP positive farms just because they knew that's what we were looking for.

Sarah: 24:41

Yeah.

Rosie: 24:42

So it would be interesting to know based on like another NOM survey if they're looking at that again. But within flock prevalence was where it was really interesting. So we split it into groups, 0%, 1 to 10%, and then over 10% of the flock affected. And then in my mind, the 1 to 10% of is what we were kind of looking at as you know, is this potentially a level of OPP that maintains itself at this low level versus the over 10%, is that gonna just continue to increase over time without any kind of control efforts? So we had we had 25%, so five out of 20 farms had the zero percent OPP. And then we had six out of twenty that, so 30% that were one to ten percent, and then forty five percent of our farms tested had over 10% serial prevalence. So a huge range, and I thought it was really interesting. Any of the flocks that were positive, that range was from 1.6% of the flock affected and as high as 56% of the flock affected. So there's some huge variability in the amount of OPP within these positive flocks.

Sarah: 26:01

So all right. So yeah, so possibly people who already knew they had a problem. And it would be so interesting to go back.

Rosie: 26:11

You said that was 22, so maybe like 27, go back and see how these flocks have changed, you know, and if you're cleaning up or not really worrying about it or or what especially because you know, like I said, the just the act of doing these surveys and testing for these things was an educational event in and of itself. Folks were like, why do we care about OPP? I thought we didn't care, and so just talking to them about what it looks like, and you know, like you know, the whole palpating others, teaching them how to do that. So there were a number of flocks that participated in this that changed so it would be interesting, and even if they weren't part of the study, but it would be neat to know like if you had heard of something since this, you know, project took place, if you changed practice.

Sarah: 26:59

And yeah, yeah. Yeah. And one thing, just for anybody who's not familiar with the lentivirus, these land, these sheep, the yews could easily have had multiple years of babies before they're showing any clinical signs. Like we don't see clinical signs until they're like five-ish or older. And so, and it is passed through the milk. So they're nursing these babies and passing it to the next use, the next season of use if they're keeping them. So um it's not like as soon as they have their first set of babies, it's gonna be obvious that they're positive. Um, they can have multiple babies before if without testing, before we would know if we're just using like a hard bag as a clinical sign.

Rosie: 27:46

Yeah, and that is something that's actually up in the air or like is under kind of it's being questioned at the moment because they're am I speaking? No, no, like you that's kind of how we understood it forever, right? Like CAE is exactly like that. Okay. There was a study that came out of the US mark in Nebraska that basically suggested that only 8% of lambs actually got OPP from their dams. Really? And yeah, most of those lambs weaned OPP negative. So we were like, huh, that's interesting. And there's some control programs out of Minnesota that are relying on that. And, you know, basically saying test replacement use at weaning to see if they're negative. I am excited to be collaborating on some projects with Dr. Fauna Smith, who's really interested in this area. She's an immunologist, an internist and superhuman. And so she, you know, we're looking at if it is a testing challenge, right? Because like they don't usually come up positive on this test until they've had it for six months. So maybe we're just not able to detect it until they're weaning age. Or is it that it's truly more vertical transmission than horizontal? So that transmission ecology, I guess, is what she's looking at. We have a flock, a research flock in Hoplin, California, that we have tested them all and we've separated them. So we now have a positive flock and a negative flock. And that's what we're looking with, the positive flock. Like if we can detect when those lambs actually if they have viral particles circulating before they show up positive on the ELISA or looking at those kinds of things. Yeah.

Sarah: 29:35

Well, let me know when you publish that.

Rosie: 29:37

Yeah.

Sarah: 29:39

Yeah. But you know, that doesn't surprise me because any of us that have tried to help a herd, even CAE, a herd or a flock, clean up, and you like get a positive, so you test everybody else, and you're like, wait, this is her direct sister, or this is her daughter. Why are they negative? And you're just like, I don't know, I can't explain it. Yeah, I don't know. And just, you know, you know, they were sisters and she has it, or these two have lived together for 15 years. How can this one not have it? So yeah, it's definitely, I mean, I think all of us have known that we don't know all of it. We don't totally know how it works. So yeah, I'm I'm so glad you're looking at that. Yeah. Okay, so so we did the testing. Okay, now let's jump into the results. Let it what do you what what were correlations that were common sense or were not? And you know, what are the the big takeaways we need from this that we can apply to our life as small ruminant vets?

Rosie: 30:36

So we definitely had the utter abnormalities correlated with the orphan lambs. That was a big relief to me. And then we had, oh gosh, we'll so that Rose did a multiple correspondence analysis, which is a great way of basically visualizing these kind of qualitative data. So it's not as like, you know, it's more of saying, like, what seems more closely related, what's important to consider together. And that is where, you know, animals that were in smaller flocks, they tended to be in more intensive management systems. They had a lower risk. Oh, yeah, right. And they had a lower risk of actually developing other issues, or when they had them, they were monitored and treated more effectively. And whereas larger flocks, you know, understandably, they tended to be more extensive. They had kind of more traditional weaning times around 90 age, tended not to use lambing jugs.

Sarah: 31:39

We didn't talk about that, but that was something that you did ask about was how they treated either injectable antibiotics, intramammary antibiotics, or what was the third one? Thought there was three options.

Rosie: 31:53

Yeah, I don't know if it was just culled or if they were treated.

Sarah: 31:57

Maybe that. So, I mean, that was another piece of the puzzle is once they decided they had mastitis, what they did about it.

Rosie: 32:05

Mm-hmm.

Sarah: 32:06

And did you ask what antibiotic people were using or not really?

Rosie: 32:10

We didn't because we the survey was pretty long as it was, so we didn't want to get too complicated. But yeah, and these so in these larger operations, they were less likely to treat for mastitis. But when you think about when they're identifying it, if they're identifying it as fat weaning specifically as a culling strategy, then that makes sense, right? Like they're they're not identifying it to treat her to get her back into production. They're identifying it because they're like, okay, she doesn't have a good bag, she won't be able to raise a lamb next year.

Sarah: 32:46

So it yeah, it's antibiotic stewardship, that's not a bad thing, right?

Rosie: 32:50

Right, right. We're not just using antibiotics without really even knowing if she'll recover because when you know the next time we look at them is that they're pre-breeding vaccinations if they're doing that. So yeah, and that kind of made me think is there a a way that we can better identify these youths earlier on? Is that important? If we did that, would there be an effective treatment for them? So yeah, that's kind of some of the things that I have a study going on at Hoplin that's looking at mastitis pathogens in sheep. And we're looking at kind of trying to answer those questions.

Sarah: 33:27

Nice, nice. Yeah, you know, we're so used to worrying about mastitis in a dairy, right? And so now you take away that intensive, we're touching them and seeing them every day to more of a rangeland kind of they're living their best lives out there. Yeah, yeah. And I if my husband was sitting here, he would tell you that you need to put temperature sensors on drones and floods and see who who's hot. That's what he would.

Rosie: 33:54

So we could just have rovers on the ground that are looking at udders to see if they're like udder specifically is inflame. That would be cool.

Sarah: 34:05

I feel like you could you could train some dogs to do that. I feel like if we can train dogs to sniff out diabetic issues, I feel like we can teach them to sniff out mastitis. Yep. I think we have a niche market. So talk talk to me about the the lambing jugs. So better or worse.

Rosie: 34:25

Well, so it's a difficult one. I mean, I think the lambing jugs with the smaller flocks allowed them to identify mastitis early. They were able to, you know, if they're treating, they're treating based on, you know, having clinical signs. So they're probably more able to keep use in production for longer, which is important. All of our zero OPP flocks were less than a hundred. So not all of our less than a hundred OPP flocks were negative, but any of them that were negative were less than a hundred and in a more intensive system. And so, like, you know, like you said, when you palpate an OPP udder, you know it's wrong. So I think there's certainly something about having an animal inside for the specific purpose of monitoring the first two days of life. Right, right. You know, they're not just in there because it's cold, they're in there to make sure they're bonding, make sure that they're nursing and doing all of that right. And so I think they're able to identify those things, it seems, based on okay.

Sarah: 35:35

So jugs, good idea, but maybe not practical for the bigger operations.

Rosie: 35:41

Yeah. Yeah. It's a huge infrastructure cost. And a lot of our growth in California is in contract grazing. And I'd say there's a lot of challenges with that type of operation. But one of the nice things is that you don't have this huge cost of having to have all these facilities in order to do that type of work. So interesting.

Sarah: 36:01

So hopefully, maybe some of these herds that participated walked away with more information, more help in managing their mastitis. It's hard to imagine that subclinical mastitis doesn't have any effect on the land's growth, but it's gotta be important, right?

Rosie: 36:19

We so that's another study that started after this. Was I mentioned that I'm looking at mastitis pathogens at the hoplin flock. Um, we are also doing California mastitis tests on everyone and then culturing everyone. And so we're also looking at how predictive the CMT is for mastitis pathogens in general, and then you know, if any of them will be able to kind of see based on lamb, we have lamb birth weights and lamb weaning weights, and then litter size. So we should be able to look at that lamb performance metric and see if any of these pathogens are more associated with poor performance in lambs.

Sarah: 37:06

For anyone who doesn't know, the CMT it stands for the California milk test. And basically what you do is you squirt some milk into this plate on a cow, there's four little things, so you know which teat is which, but is it two with the sheep? I don't know. Yeah, um I mean same plate, but okay. And you only use half of it with the sheep. Yeah, and then you squirt this purple stuff in, and the milk changes by how much bacteria it is. And it's just a quick, I want to call it dirty, a quick and dirty cow side, sheep side, goat side test to tell if there's a lot of bacteria in the milk. It's just a really user-friendly, easy to do, not expensive way to get a sense for mastitis. Right? Is that how you summarize it?

Rosie: 37:56

Yeah, yeah.

Sarah: 37:57

Yeah, lots of dairy farms use it. It's it's a it's a great tool.

Rosie: 38:01

Yeah, and it may, so because sheep, the way sheep produce milk is similar, or it's it's milk americrine secretion. So it's the same as how cows make milk. They basically like open up their cells and the milk falls out, kind of a thing. Whereas goats do apricine, which is where they butt off pieces of their cell and that goes into the milk. So depending on which method of somatic cell count you're doing, with goats, you can end up with higher somatic cell counts if they're looking for cells. But with CMT, because it's actually binding DNA, is what makes it kind of slimy, then it it should be more similar to kind of that range of somatic cells that we're looking at. So but you see all these research studies that say it, you know, it does correlate well or it doesn't. So we're like, well, it will be one additional paper to say how well it correlates or not. So yeah. But yeah, it's a really useful sheep side tool. Another thing that's on here just in kind of the discussion is about how the mortality in neonates is usually linked to failure of passive transfer or starvation. And starvation, people check that as like one of the most common causes for neonatal death. But that other side, the failure of passive transfer is also something we're interested in looking at. If you know colostrum quality is different in use with OPP. So that yeah. That would be really interesting. Yeah, because like you said, it's a progressive disease. So, you know, you don't see that really hard bag until they're about five or six years old. But before then, there's you know that interstitial inflammation happening, it's just not it so bad that you can just feel it immediately. So at what point are we starting to see these changes? Right.

Sarah: 40:07

So this is just a stepping stone for all the it's nice to kind of take a step back and get a bigger picture occasionally and really like have a sense of like, you know, so much study is minutia, and this is like the opposite, right? This is like, let's step back and look at a lot of things and see, you know, what's important. And I mean, a huge we were talking about this before, a huge thing that's important is if we are trying to treat these hard bag OPP positive with antibiotics. That's inappropriate. And so, you know, we really need to, as we've talked about so much, protect our antibiotics so they don't get taken away from us. And if 50% of your flock is lenty positive, you know, that antibiotic's not going to do them any good.

Rosie: 40:57

Yep. Yep.

Sarah: 40:59

So I think understanding OPP, even if it's not hugely affecting our flocks, has other implications that we need to talk about as veterinarians for sure.

Rosie: 41:12

Yeah, absolutely. Yeah. And we had, you know, we worked with some of the herders from these flocks, and they're like, yeah, some of these ewes, they look like they're just they, you know, have bad genetics, they're not making milk. Like we, the lambs, they're not sick, but they're not well. Like basically they say they're not sick because they don't respond to antibiotics, but they're they're definitely not doing well. And they they recognize that the ew is not making enough milk, but they don't, you know, before working with them, they didn't know about this disease. And so now that we have like, you know, a reason for this problem and a way to get these sheep out of that flock, it's like, yeah, it'll be really neat to see in two years what change that is made.

Sarah: 41:57

That's huge. All right. Well, thank you so much. I have my ending question. Are you ready? Did I ask everyone at the end? So, what do you see as the next problem that researchers need to think about and address in small ruminant medicine?

Rosie: 42:10

Well, oh gosh. I think the having better diagnostics for Yoni's disease would be an amazing thing. I think that we have a couple projects or one project right now on that, but we need many, many more in that region. I think we have a lot of good research on the abortion agents and how they're evolving and how our vaccines that we currently have aren't covering. I mean, they probably work for some of them, but a lot of the abortions that we see out here, the vaccines aren't protecting them. And and I think that's less of a research problem, but more of a collaboration with agencies issue. Like we need more vaccines for our clients.

Sarah: 42:57

Like, oh, Q fever, maybe? I don't know.

Rosie: 42:59

Right. Exactly. Yeah, yeah. I was with CDC and I was talking about, you know, this big problem that we have with our sheep flocks that causes abortion. It really impacts our, you know, ability to raise a commodity crop. But oh, guess what? It's also a zoonotic disease. And like, you know, like these are huge issues that are just, you know, like while I think, like I said, some the research has been done, the issues have been identified, even solutions have been proposed, and it like we need that next step of actually getting these resources out there for us.

Sarah: 43:39

Yeah, yeah. And they have them in other countries. That's what's so frustrating. Yes. But like you said, they're there, they're just not here.

Rosie: 43:50

Yeah.

Sarah: 43:50

All right. So that is a great answer. Well, thank you so much for joining us and Boz and Bleats. You have your own podcast. Why don't you want to plug it?

Rosie: 43:59

Yeah. So we I uh do a podcast with my good friends Dan Macon and Ryan Mahoney. They're both sheep producers. Dan Macon's also a county-based livestock advisor and or livestock and natural resources advisor. And we do a podcast called Sheep Stuff You Should Know. And if it's pretty much all about sheep, but it's all the different aspects of production that as a veterinarian I am was pretty ignorant to. So it's I learned a lot and it's a lot of fun. So great.

Sarah: 44:31

And we can just find that like on our Apple Podcast app and all the places.

Rosie: 44:34

Yep.

Sarah: 44:35

Perfect. All right. Well, thank you once again.

Rosie: 44:38

Yeah, thank you.