Maine Farmcast Episode 16: Updates in Internal Parasite Research with Dr. Jeff Lehmkuhler
On this episode of the Maine Farmcast, I am joined by Dr. Jeff Lehmkuhler, Extension Professor and Beef Specialist for the University of Kentucky. Jeff discusses his diverse background in agriculture and some pertinent research results from his recent research in accessing the efficacy of different types and routes of administration of common cattle dewormers on the market. Stay tuned for next week’s episode when we discuss pasture health and regenerative practices of grazing livestock.
Dr. Jeffrey W. Lehmkuhler was raised in southern Indiana. He attended Purdue University and obtained his M.S. in silvopastoral systems and Ph.D. in beef cattle nutrition from the University of Missouri. Jeff continued his career at the University of Wisconsin-Madison in 2001 and was hired by the University of Kentucky in 2008 where he now holds the title of Extension Professor. His internationally recognized programming has spanned five countries and covered a diverse range of ruminant production from dairy steers to yaks. Jeff’s external funding exceeds $6M dollars and he authored more than 125 newsletter and popular press articles, 66 abstracts and journal articles, and 46 proceedings and extension publications. A key to his success has been forging relations with colleagues to work as a team. Jeff received the Agri-Communicator award in 2004, Southern Region ASAS Extension award in 2016 and M.D. Whiteker Excellence in Extension award in 2021. Jeff and his wife, Gwen, have three children.
Episode Resources
- Learn more about Dr. Jeff Lehmkuhler
Transcript
Colt Knight: 00:25
Welcome to the Maine Farmcast. I am your host, Dr. Colton Knight, associate extension professor and state livestock specialist for the University of Maine Cooperative Extension. And I have the pleasure to be joined by Dr. Jeff Lemhkuhler of the University of Kentucky. Jeff is a extension professor and, beef specialist for the University of Kentucky, and this is gonna be his 3rd time visiting Maine.
Jeff Lehmkuhler: 00:51
3rd time, but first time on your podcast.
Colt Knight: 00:55
Yeah. The the podcast is, as of this recording, is a relatively new thing for here in Maine. And guess who I learned that from?
Jeff Lehmkuhler: 01:03
Gotta be that Rentfrow character. Yeah.
Colt Knight: 01:08
No. Jeff, actually, the last time he came out, he he brought a portable podcast system, and we recorded a podcast at my farm. And I’ve been thinking about podcasting for a long time, and Jeff made it so approachable. You know, he just set a microphone out there and we just talked. And I was like, this is, this is the way to go, and it’s a good way to get information out to the public.
Jeff Lehmkuhler: 01:32
You know, Colt, I’d like to take credit for that, but, actually, it was one of our other colleagues at Kansas during COVID that called me to do a podcast. And I thought, you know, this is a great way for us to continue to reach people during the COVID shutdown, but then also reach a clientele base that we probably don’t have coming to our daily meetings or evening meetings. And so, I thought why not give it a chance? And, it’s gone off pretty well, and I hope yours does the same thing. I think folks will find this information.
Jeff Lehmkuhler: 02:02
They can grab and listen to it while they’re mowing hay or driving down the road.
Colt Knight: 02:06
Yeah. And so you have a pretty strong agriculture background, you know, growing up on a farm and and going through school and everything. So I’d like to hear more about that.
Jeff Lehmkuhler: 02:17
So so not as strong as as some of my other colleagues in the in, you know, my my family has had a little bit of a different history. My grandparents had a small dairy. They grew up trying to to farm and and milk cows. And, it seemed like every time they would get a step forward, they’d have a step that would come in and and take them backwards. For example, they built up a new dairy barn, and a tornado came through and took it down, within the year.
Jeff Lehmkuhler: 02:47
You know, back in that time frame, they didn’t really have, a lot of insurance money coverage in that, and so that set them back. And then, in the seventies, they had borrowed some money and bought in a bunch of dairy heifers, and, they wound up being TB positive. And then the buyout then, you know, they didn’t get the full value of what they paid for those genetics, and they lost some money there. But, my dad then, he he also back in that time frame, he went on and, he was actually working for the local co op at the time and the local co op sent him out to, Graham School in Kansas to learn the artificial inseminate, beef animals and preg check and that. And so they were going to offer that as a service.
Jeff Lehmkuhler: 03:32
If you remember, it was kind of back in the that that time frame when a lot of the continental cattle were first coming in.
Colt Knight: 03:39
Mhmm.
Jeff Lehmkuhler: 03:40
A lot of semen was coming available on those Charolais and Simmental. And so they they were pretty forward thinking at the time. But, then, you know, in a lot of our states, as far as pregnancy diagnosis goes, can only be done by a veterinarian. And so that kind of put the kibosh on that part and then the artificial insemination. It probably didn’t take off as fast as what people thought it would back then because we were dealing with natural heats and heat detection, which takes a lot of labor.
Jeff Lehmkuhler: 04:13
Right? You could be out there twice a day at least. Whereas today, we’ve learned a lot about, how to synchronize estrus and using protocols to have fixed timed insemination. And, so I think he was a little bit ahead of his time then, but then he went on and worked for a corporate farm. I think at one point in time, they were up to about 5, 600 cows.
Jeff Lehmkuhler: 04:35
And we used to live on those different farms. They were moved kind of occasionally from house to house, but to manage those cattle. And then, later on, they got into the Tennessee Walking Horses. And so got a little bit of exposure to that. But, I’ll be honest, was kind of, you know, arms length away.
Jeff Lehmkuhler: 04:58
I was a small kid at at all those times. And then, I don’t like to admit this a lot, but, we got in the sheep. When when my grandparents sold their dairy in the late seventies, we moved to small acreage, and the only thing we really could run there were were sheep. And, so we started a small flock, and and that’s probably the the highest level of of exposure to animal agriculture I had as a kid. And then, went on to Purdue and, thought I was going to be a vet.
Jeff Lehmkuhler: 05:33
Got in there about a half a semester and then realized that I’m not sure that that’s what I really want to do. And part of that was, I think it was middle school I started working at our local feed store or feed mill. And I worked there all through middle school, high school, and even a couple years in college. And, I got intrigued by all these different farmers. They’d come in and, you know, Colt, you might come in to ask for some beef feed and you had this formula that had ear corn in it and and spelt and all this other stuff.
Jeff Lehmkuhler: 06:08
And then the next guy would come in and he had just corn and soybean meal. And so that feed stuff nutrition kind of sparked interest. And, and then I went kind of down into this deep rabbit hole. I had a really good advisor at the time and he asked me to stay up 1 summer to run his rheum and nutrition lab because his technician was going away for the summer. I said, there’s no way I can do that.
Jeff Lehmkuhler: 06:39
I said, I got to go back to the factory at home. At home, we have a lot of furniture factories and they pay pretty good for summer help. And, I worked there 1 summer and was planning on going back the 2nd year and he said, no, you need to do this. He said for your career and that you need to think about doing this. And I talked it over with my parents and decided then to stay up there.
Jeff Lehmkuhler: 07:02
And I guess that was the hook line and sinker, if you will. So, at that time, we were working on, our BST work. So, the recombinant of bovine somatotropin and trying to get it, it would have been out on the market, in that kind of nineties time frame. So I was involved in some of that research and pulling samples and then, kinda just kept on going with it.
Colt Knight: 07:34
It’s it’s funny you say that. One of my, better professors in graduate school, doctor Bob Collier, was, one of the fellows that that developed that rBST down in
Jeff Lehmkuhler: 07:47
Florida. It’s a small world, isn’t it?
Colt Knight: 07:49
It is. And I’m not even in the dairy world. And, you know, it’s it’s like you could still find these connections across the country. And and one of the reasons I started this podcast is I get to meet a lot of interesting folks and a lot of knowledgeable folks. And how do I get to share that knowledge with with the population here in Maine?
Colt Knight: 08:08
And I think this podcast format is a good way to do that.
Jeff Lehmkuhler: 08:13
I think it’s a fantastic way. You know, it’s not every day that we get to, learn a little bit more about how different people’s past take them to where they ended up. And we we noticed that a few years ago in our beef production class. And at the end, we always have the very last day an exchange with the the students and ask them what they liked about the class, what they didn’t like about the class, and we asked them to be brutally honest. And in one session, they asked us about our backgrounds.
Colt Knight: 08:43
Mhmm.
Jeff Lehmkuhler: 08:44
And then they said, we wish we would have known more about you when class started. And so we now incorporate that at the upfront because I didn’t have a lot of beef experience when I went to college, and my beef experience came really when I got into grad school. I’d been around beef cattle. I worked beef cattle with my dad and and others, But, you know, I was the one back there pushing animals in that. I wasn’t the one up doing the work at the head shoot and some of that.
Jeff Lehmkuhler: 09:13
So, our students, I think, relate to that knowing because we have, what, less than 2% of, the population that’s directly tied back to
Colt Knight: 09:25
Mhmm.
Jeff Lehmkuhler: 09:26
Animal agriculture today. And, so a lot of our students are coming with little or limited exposure to livestock management. And so for them to see us coming through and being successful and developing careers in an area with limited experience helps them see what they can possibly do with hard work and, you know, that desire to learn and willingness to learn. So
Colt Knight: 09:52
My family background is actually in coal mining. I was a right out of high school, I went to work in a coal miner. I was 3rd generation coal miner at that point. Now we had a show horse stable. So those Tennessee walking horses and racking horses, we were heavily into that.
Colt Knight: 10:11
You know, we probably had 30, 40 horses in our stable at one point. You know, there was some times I was riding I’d get off the bus from school, and I’d go straight to the stable and ride horses just back to back until dark. And it’d be 10 o’clock before I got home. And I just thought that’s what I was gonna do with my life was was to be a horse trainer, so I went to the horse capital of the world, Lexington, Kentucky to get my degree. And at the time, I didn’t even know animal science was a degree.
Colt Knight: 10:41
I didn’t know that you could study livestock stock in college. I thought you went to college to be a doctor, lawyer, or a teacher. You know, I didn’t know there were all these different things that you could do. And one of my first classes, there were some students there that got to live at the teaching farm if they worked at the teaching farm. And I said, how do you get that gig?
Colt Knight: 11:00
I wanna get out of this dorm room and out on the farm, and I ended up at the swine unit. But with that said, I still thought I was gonna be a horse person. And one of the beef professors there, doctor Fred Thrift, is the one man, the way he presented beef cattle production, and he would take us out every week to a different farm to to castrate, dehorn, brand, vaccinate. I fell in love with the beef cattle industry. And so I went to graduate school for beef cattle and got out of horses and into beef cattle.
Colt Knight: 11:37
Now that I’ve come here to Maine, I’ve had to diversify more than just beef cattle and and really get into the all the species, basically. Because that’s just the needs of the state. Nothing if not adaptable. We have
Jeff Lehmkuhler: 11:52
to be in this job, though. Right? Because you never know when you pick up that phone what that question’s gonna be.
Colt Knight: 11:57
Yeah. Right? It’s really funny. When I talk to my my hardcore academic friends that are in research and things, it’s when they calculate out a diet for their research trial, they have all the information. When a producer calls me, it’s like putting a puzzle together with missing pieces Because they’re not gonna know their all their analyses and all their different things, or they may not know some of these different things.
Colt Knight: 12:23
And you’ve you’ve kinda gotta make the best of that situation and and guess and check and put everything together. So it’s the application of that knowledge, having the education is really handy for doing that.
Jeff Lehmkuhler: 12:38
Yeah. It’s it’s, the education, you know, I always said when I when I got out with my doctorate degree and started my career, I thought I was ready to go. But little did I know that that learning curve was just going to be a linear straight line on the way up because I was a ruminant nutritionist and moved into, you know, a dairy state. And I had to learn about Holsteins and Jerseys and finishing those. And sure, I could put together a great diet, but like you said, we’re adding 1 round bale to the TMR mixer and we may or may not know what the weight is on that thing.
Jeff Lehmkuhler: 13:19
And you have to formulate the rations for that one bale because they’re not going to put a partial bale in. So the real world is really where that practical knowledge starts coming in. And that’s why I always think you mentioned Dr. Thrift and taking folks up students out to the farms, and that’s valuable, right? Because we learn I always say that as a specialist, I learn as much going on that farm visit probably that I convey to the individual because I learn about that individual’s management.
Jeff Lehmkuhler: 13:55
What do they have for feed resources? What do they have for water resources? And more importantly, because in Kentucky, and I’m sure it’s the same here in Maine, a lot of our farms on our beef cattle farms are what I would term as, and I think USDA would fit in the definition as a small farm, you know, 30 mama cows or less on average, full time off the farm employment.
Colt Knight: 14:21
Mhmm.
Jeff Lehmkuhler: 14:21
And so labor is something that we always have to think about.
Colt Knight: 14:27
And you mentioned learning on the job. And, you know, as extension, we learn as much from farmers as they learn from us sometime. And so being able to go to all these different places, we can we can pick and choose those really good ideas that people are implementing and maybe maybe rearrange some of them to to make it it fit the the science a little better. But I learn a lot by inviting guest speakers like doctor Jeff Lemkeuler to Megan. So we had the first time I invited him up, he was a guest speaker at our Cattlemen’s College.
Colt Knight: 15:02
And, you know, the Cattlemen’s College might last a half a day, but Dr. Lehmkuhler up here for 3 days, and we’re driving around looking at beef farms. He’s updating me on all the the the most recent science in beef cattle production. We can have discussions, and it’s like a professional development opportunity to me. And then I can I can use that information to the with the producers here in Maine? And I really enjoy that aspect of inviting, guest speakers to the state, You know, because historically, as like a state beef specialist, maybe you would go to the animal science annual meeting, and that’s where you would get that information.
Colt Knight: 15:44
And you’re working in beef every day, all day, so you get to stay up to date on all the literature. Now that I’m more diversified, I don’t have the time to spend on really digging deep into the the literature. So so having folks like you come up and and update me, it’s really handy. I appreciate that.
Jeff Lehmkuhler: 16:06
Colt, you know, I think that’s, a fantastic point. And I tried to make that clear. I was fortunate to be awarded one of our National Extension Awards, and my presentation was really about teams and teamwork. And I learned early on that again, I went to Wisconsin, and I was the only bee specialist in the state. And networking with other colleagues was critical to help me start my career and get going and have that mentorship.
Jeff Lehmkuhler: 16:39
But you build this team and so I built a team and I had folks in the forage side, and I could ask them questions about forages. We had extension veterinarians, and I could learn more about the health side from them. You know, the genetics. I wasn’t trained in genetics, but we had the dairy geneticists, and you could learn from them. So I would say that, you know, our interactions with our colleagues, you know, those are so valuable to help us learn, little pieces that you never know when you might be able to pull that piece out of your brain and say, oh, yeah.
Jeff Lehmkuhler: 17:16
I remember us talking about that in the car or at the meeting. I remember them presenting that abstract. But I do wanna go back and talk about that on farm. You know, my on farm component really stems back to my master’s work at Missouri. My master’s work was in agroforestry and particularly, it was down in the southwest corner of Missouri, not too far away from Joplin and it was on a really large walnut plantation, and and they were mowing hay underneath these walnut trees.
Jeff Lehmkuhler: 17:51
And, you know, in this humid south, it gets a little hard for hay to cure. And then you put in a bunch of trees that is shading out a lot of the windrows, and they were looking for an alternative. So we looked at, you know, grazing, dairy steers the first time. We actually, you know, we bought in some some beef calves, but, let’s just say they were a little bit too wild to stay in. We used 2 strands of electric fence, and, it was pretty clear when they were jumping over 6 foot panels that they weren’t gonna stay in 2 strands of hot wire.
Jeff Lehmkuhler: 18:25
So we punted and and moved to some dairy steers. But, that that was my master’s work that was on farm, and it was several hours from campus. And I learned a lot about on farm studies and the value of interacting with the livestock managers and learning because little did I know at some points in time, they may have been providing some feed to the cattle. And, you know, this was a grazing study, and we really didn’t want supplemental feed going to the cattle and impacting gains and that. And, you know, that there’s just those little things that you know why it’s important to begin asking questions because they don’t know that it’s going to mess up your study if they’re doing this or that.
Jeff Lehmkuhler: 19:19
So you have to be very clear, very specific, but then you need to start asking them, what do you want out of it? What do you want to see? And, you know, the the 1st year I did my study, we were planning on going down to do a 2nd year. And they said, you’re not gonna do the continuous grazing. It’s causing too much damage under the trees, and they’re making too much trails through the forage.
Jeff Lehmkuhler: 19:42
So they we had to punt then and and go to 2 different rotational grazings, and we looked at, you know, stocking density then. But that on farm component helped me understand too the need to be flexible and the ability or not ability, but the need to be able to answer some relatively broad questions and maybe not get into the truly controlled science that we could do maybe in an on campus or in a university facility. But it also gave me this greater appreciation of understanding the applied science and how that research could be used by cattlemen in that certain area, in that certain system. And at the time, you know, we moved on and did some other work where we tried to establish trees in open fields and develop a civil pastoral system. And, you know, it’s not easy going out there and planting 1500 trees and then knowingly gonna turn livestock in and just watch them damage them.
Colt Knight: 20:51
Yeah. But, you know, speaking of applied research, what new things do you have going on there in Kentucky that you’re working on?
Jeff Lehmkuhler: 21:00
Oh, good question, Colt. So, we were fortunate. We we just wrapped up a a study. This is one that I’ll share with you right now is, it was sponsored by Merck Animal Health and our Kentucky Beef Network, and it was a field study for fecal egg count reduction and fecal egg monitoring. So, my colleague, doctor Michelle Arnold, who’s our extension veterinarian, and I worked on, getting this project started, involved a 180 groups of cattle in Kentucky.
Jeff Lehmkuhler: 21:36
We were sampling 20 animals, or the goal was to sample 20 animals in the same age class. So either 20 mature cows or 20 feeder cattle or 20 suckling calves. And we sampled spring and fall. And then what we did is went out there and took fecal samples, allowed the farmer or the livestock manager to use any deworming product that they wanted. So they could do a pour on, they could do an injectable, they could do a combination, whatever they wanted to do.
Jeff Lehmkuhler: 22:10
2 weeks later, then we went out and then we randomly collected 20 fresh fecal samples again and had those sent to a commercial laboratory and they did, fecal egg counts. We were looking for reduction in those. As as you think about that internal parasite, it has about, you know, 19 to 20 day life cycle. And, the eggs come out into the feces, and then the eggs hatch, and they go through basically the first three stages, outside of the animal. The animal then consumes the larva in stage 3, and then it develops into that stage 4 adult inside the animal.
Jeff Lehmkuhler: 22:49
And then when they’re adults, they start shedding eggs. So the the expectation is is that if you have adults and you use a deworming agent, that you should see the fecal egg count be reduced. And the parasitologist typically will hold kind of a standard for a reduction of 90% or greater as the threshold to determine efficacy of a product. So in other words, if if you pull day 0 samples and and you’ve got a 100 eggs per gram, you’re hoping that 14 days later after the deworming was done, that you would have 10 eggs or less because that would be that 90% reduction or greater. So we did a pretty pretty intensive study, like I said, a 180 groups.
Jeff Lehmkuhler: 23:45
The target was a 100 in spring and fall, but, you know, some groups fell out and you couldn’t get pres and post and this and that. It’s interesting. We found our cows to be relatively low in egg counts, and that makes some sense. You know, our extension veterinarians will tell you and and our veterinarians will tell you beef cattle, when they mature, begin to develop some resistance to internal parasites. And so they can they can harbor internal parasites and and they don’t have as negative influence on them.
Jeff Lehmkuhler: 24:22
Our young livestock tend to be more susceptible and fecal egg counts are higher, but part of that is dilution too. Right? I mean, called a 600 pound calf isn’t eating nearly as much as a 1400 pound mature cow, so you have this dilution for fecal matter kind of diluting things down a little bit. But, we did see much higher numbers in our younger cattle compared to our adult cattle. And, we had some thresholds.
Jeff Lehmkuhler: 24:54
They had to have at least 10 eggs per 3 gram sample or higher to be included in the analysis. If they didn’t have that, you began to see a lot of, too much variability in the fecal egg reduction. And and this is a sponsored project that’s being done in 5 other states, or 5 states, and so we had a standard protocol for analysis. But what we saw is, you know, almost 44, 45 percent of the groups we had to throw out because they were actually less than 10 eggs per 3 gram sample. And you sit back there and you’re kind of like, dang, I lost all that data.
Jeff Lehmkuhler: 25:39
Right? But on the flip side, it’s like, hey, this is a pretty good thing that we’re seeing this many groups being that low, and especially in the adult animals. The other thing that we saw is we compared macrocyclic lactones, which are the family of products that your IvaMex, Dectamax, Cydectins fit into. There was certainly a difference between generic and either we’ll call them generic or maybe second generation. So after the initial products ran out of their patent license, then the 2nd generation products would come on the markets.
Jeff Lehmkuhler: 26:32
There was significant difference in efficacy in the 1st generation or name brand products compared to that 2nd generation product. 2nd generation product, for whatever reason, didn’t seem to reduce the fecal egg counts as much. And I I don’t know if we’ll see that across the board on all the other samples that come in from all the other states, but that’s what we saw in ours. We also saw that, compared to the the white paste oral dewormers, they they were all 90% or greater efficacy. However, that said, very few of the farms use white paste oral dewormers.
Jeff Lehmkuhler: 27:15
So the data, I’m a little I’m a little bit, conservative in saying that they’re better than the other ones. I think we need a lot more data to come in on that. But, our stalker guys are using the combination of an oral white paste with a pour on. And the reason for that is you you don’t get any residual protection with your white paste.
Colt Knight: 27:42
Mhmm.
Jeff Lehmkuhler: 27:43
Whereas, the macrocyclic lactones, you know, you’re gonna get 14 to 28, maybe 42 days of extended protection on some of those different internal parasites.
Colt Knight: 27:55
Did you try injectables at all?
Jeff Lehmkuhler: 27:58
We did, and so we actually went on. That’s a great question, and thanks for that. We we broke out injectable versus pour on within the macrocyclic lactone, and the injectables actually performed just a little bit worse than the pour ons. But again, very low numbers. We had about a 65% reduction in fecal egg counts with the injectables where we were running about 73, 74 in the poron.
Jeff Lehmkuhler: 28:32
Yeah. So, there’s there’s a lot more work to that needs to be done on that. You know, again, I mentioned this, we had somewhere around 30 groups that had the macrocyclic lactone in the spring and then another 30, 35 groups that had it in the fall. So, you know, the 180 farms and you get down and you only got 60 within a treatment group. But that’s just part of the work.
Jeff Lehmkuhler: 28:59
So we’ll see what the other states roll in at. And and we only had, I’m trying to think, 2 groups in the spring that got the oral treatment, the white paste dewormer, 2 groups of mature cows, and 2 groups of feeder cattle that got, a combination. In the fall, we shifted and tried to get more feeder cattle groups tested. So in the fall, I think we had about 25 groups that had white paste dewormer either alone or in combination. So we got a bigger sampling in that false set.
Jeff Lehmkuhler: 29:37
Because we’ve seen we’ve seen that the cows had very little fecal eggs, so we shifted to kind of pick up more of the young calf to see how the products are working. So anyways, long story short, it’s some interesting work. I think my suggestion or recommendation to producers are to work with your veterinarian. Most of our farmers had actually, pretty much a 100% of our farmers had not done a fecal egg count prior to this work. So it may be good to work with your veterinarian and pull some samples and and look and see what fecal egg counts are to get a rough idea what kind of internal parasite burden may be on.
Jeff Lehmkuhler: 30:24
You know, the small ruminant folks have been doing this with the, FAMACHA or however you want to say that. You probably know better than I do.
Colt Knight: 30:33
FAMACHA is the correct pronunciation.
Jeff Lehmkuhler: 30:35
Alright. And so we we don’t really have that on the b side, but we’ve got the fecal egg count tool that we could look at. Now I caution that because my my good, colleague, Dr. Arnold, who’s a veterinarian, she, you know, reminds me all the time that, you know, Dr. Lehmkuhler, you can still have some some issues because there’s, you know, some of the internal parasites may be causing some tissue damage in feeding before you even see fecal egg counts going up. So anyways, it’s just a tool that we can use, and I would I would recommend farmers work closer with their veterinarian on this. And then we have concerns about resistance.
Jeff Lehmkuhler: 31:16
And so we took some of our samples that were relatively high, and, the commercial lab sent those out to Colorado State and they did PCR analysis to determine what specifically was coming in. And then so we noted that in, in all the samples, cuperia and the brown stomach worm was there. And so it seems like in just like what the small ruminant folks have seen is cuperia tends to be the one that is maybe a little bit becoming more resistant to some of our products that we have available to us to use.
Colt Knight: 31:58
Yeah. As you mentioned, the FAMACHA and the the small ruminants, the FAMACHA actually stands for Fafa Millan. He’s a South African guy that developed the technique, and the CHA is is for chart for keeping records on on looking at the the membranes of the eye to determine basically how anemic the animal is. So you’re using a color chart to see how anemic the animal is because that that test only tests for one specific parasite, the barber pole worm. And those are like little vampires, and they get inside the digestive tract, and they lacerate open the digestive tract, and suck their blood out.
Colt Knight: 32:39
And younger animals can can die within a week or so, you know, from from a heavy parasite load like that. And the barber pole worm has become the most economically important parasite for for small ruminant production. And, man, those things are getting resistance to most of our dewormers, and you really have to work with your veterinarian in your local area to identify which dewormers are still effective in your area.
Jeff Lehmkuhler: 33:12
Yeah. And this and and that’s why it’s important, right, to work with that veterinarian and find out what’s susceptible, what’s not susceptible into anything anymore. And there’s the principle of refugia, Right? And and that’s where some animals maybe are not treated, so that they’re shedding eggs into the environment that will develop into adults that have never been exposed, and then, hopefully, those larvae will compete with animal or with larvae that, have been exposed and are resistant. So doctor Kaplan is kind of well known on the parasitology side, and he he has some general recommendations when you find products that are maybe, becoming less, efficacy the efficacy is starting to wane on some of those products.
Jeff Lehmkuhler: 34:04
And one is maybe not to deworm adult animals, Maybe do it on a production basis. So if if it’s, say, stocker cattle gains, take those top 20 to 30% that are gaining at the top and then don’t show signs, visible signs. Don’t treat those and treat the bottom 70, 80% that aren’t performing where you think they should be or the bottom 20%. And then the other thing is is, and you could do it randomly. Right?
Jeff Lehmkuhler: 34:35
You could just randomly not treat some. But, the the other thing is then to use combination. One thing that we get questioned about a lot is rotating products. So this, you know, this first time in spring, I’m gonna use, this product, and the next time, I’m gonna use that product like what we’re kind of trained to do with fly tags. Yep.
Jeff Lehmkuhler: 35:00
That’s probably not the way to go with with internal parasites. And and that’s where this fecal egg count and working with your veterinarian becomes important because you probably should stick with the same product that you’ve been using until it’s not working very well for you so that you can then shift and start using another product and and change change it a little bit whenever you start noticing it not working the way you want it to.
Colt Knight: 35:26
I always growing up in the horse world, we were always told to alternate every time to a different active ingredient. And and
Jeff Lehmkuhler: 35:35
that has that mindset has changed. And and, you know, that’s today, it’s stick with the same product until you know it’s not working or the efficacy is below that 90%. And then think about either moving to a combination of a white paste anapuron or switching products.
Colt Knight: 35:53
And I think this information is really timely for Maine because last year, we had a super wet year, and I saw parasite issues go through the roof. I mean, I I had pig people, beef cattle, small ruminants, and and even some poultry. You know, the incidence of worms and and things were just going through the roof. And there were a lot of times, especially with pigs, people would call and say, I’m I’m feeding my pigs all this, so they’re not gaining any weight. And I’m like, I almost guarantee you got an internal parasite issue.
Colt Knight: 36:30
And the good news is is with pigs, you can treat that fairly quickly. When you’re in the small ruminant world, it’s more difficult to manage internal parasites. And in the beef cattle world, it’s a little easier than it is on the the sheep. But
Jeff Lehmkuhler: 36:47
Yeah. And that’s that’s, you know, the the wet springs, the wet so so they can dry those larvae will dry out if they don’t have moisture. So when you have a wet year, those things kind of thrive, if you will, in the environment versus a dry year.
Colt Knight: 37:05
You know, and that, you know, that’s why we use things like chain harrows in our fields after we graze is because that chain is spreading out that manure, increasing the surface area. Sunlight’s beating down on that and drying it out and and basically desiccating and killing those parasites. That’s another principle of rotational grazing too. Right? Is you’re not putting those animals back on ground that has a parasite load.
Colt Knight: 37:31
So we’re letting it sit long enough not only to let the ground rest and the grass to regrow, but we’re also letting those parasites die so we’re not compounding the the parasite issue.
Jeff Lehmkuhler: 37:44
Yeah. And I think the other thing that we I mean, parasites will always be there. You know, we we had these internal parasites for 100 of years and multiple droughts and all that. They never go away. Right?
Colt Knight: 37:55
Mhmm.
Jeff Lehmkuhler: 37:56
But in the rotational grazing, and this is particularly important for the small ruminant folks, is you’re managing that residual height. Right? Most of those larvae will only go up a couple inches on grass before they start getting dry grass. You know, it was a desiccation issue. So if you manage that residual to to keep it a higher level, then the hope is that the small ruminant folks have figured that out, particularly the goat folks where they’re using, species like that are higher grow a little higher, and it’s more of a true browse type of a plant.
Jeff Lehmkuhler: 38:41
So there’s some strategies there that we can think about too, and rotational grazing and managing residues is key. Now you never write a code. You see grazing behavior. You studied grazing behavior. The grass may be 18 inches tall, but the clover is 2 inches, and they’re gonna dry right down there and get so you can’t control everything.
Jeff Lehmkuhler: 39:01
Yeah. But
Colt Knight: 39:03
we do the best we can with what we have. And, I appreciate you sharing that that research with us, and, we look forward to hearing more from you in the future. And I would look for doctor Lynn Keuler at Future Cattlemen’s Colleges. We were planning on having him back. He always gives amazing talks.
Colt Knight: 39:23
He’s probably forgotten more about the beef cattle industry than than I know. So it it’s really valuable to have him up here. Thanks for coming.
Jeff Lehmkuhler: 39:32
Thanks for asking me to come back up. It’s been enjoyable as always and always enjoy coming up here getting good food and weather’s been awesome. Right? It’s gonna rain a little bit this afternoon, but you can’t beat this kind of 70 to 80 degree weather.
Colt Knight: 39:48
Yeah. I think we’re gonna we’re gonna hit the lobster pound tonight, get the the boiler out, and and go to town. Well, until the next time, we’ll see you on the Maine Farmcast.
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