Angus at Work

Use MLV and Killed Vaccines Strategically to Create Lifetime Immunity with Thach Winslow

June 28, 2023 Angus Beef Bulletin Season 2 Episode 14
Angus at Work
Use MLV and Killed Vaccines Strategically to Create Lifetime Immunity with Thach Winslow
Show Notes Transcript

You've likely asked the question, "Which is better? Modified-live virus or killed vaccines?" Both have their place in your herd, and if used strategically, they can work together to create lifetime immunity. 

Shauna Hermel sat down with Elanco's Thach Winslow to discuss:

  • When each type of vaccine is optimally used
  • Can they work together?
  • What kind of timing should you keep in mind?
  • How do they affect profitability?
  • What should you always vaccinate against? 
  • Where could you save some money?


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Hello and welcome to Angus at Work. I'm Kasey Brown. Today we're tackling an often asked question because unfortunately there's not a simple answer. Which is better, killed vaccines or modified life. Can they work together? What kind of timing do you need to keep in mind and how do they affect your profitability? Shauna had sat down with Thach Winslow from Elanco to discuss these questions and there were some surprising answers. So let's dig in.

Shauna Hermel:

Hi, I'm Shauna Hermel, editor with the Angus Beef Bulletin. We're here today talking with Thach Winslow with Elanco about lifetime immunity. Thach, can you tell me a little bit about, and I should say Dr. Winslow-

Thach Winslow:

Thach is fine.

Shauna Hermel:

Can you tell me a little bit about your background? Where did you come into the veterinary side of things?

Thach Winslow:

Oh, that's an interesting story. So I'm a Yankee. I grew up in the Northeast in a lobstering town. At a very young age I fell in love with the west and was working summers during high school and college in Wyoming, maybe just a tad of black sheep of the family. Kind of went my own direction. So then I ended up at VPI in animal science and graduated from there and went to vet school there too, and opened a practice in 1991, Large Animal Ambulatory, and did that for 17 years. And then my associate wanted to buy the practice and my body was starting to get a little bit, I was getting slower.

Shauna Hermel:

We do get older, don't we?

Thach Winslow:

Yeah. And so I went to the dark side. I went to work for the Virginia Department of Agriculture for Government and was regional veterinary supervisor there for five years, which was about three years more than I thought I was going to be. And then position came open as the assistant state vet in Wyoming. Working for the livestock board. So I-

Shauna Hermel:

Northeast to northwest.

Thach Winslow:

So I headed out well south, northeast, southeast, west, but yeah, so I took that position, did that for six years, and then I was made aware of a position with Elanco back in the cow calf stocker deal, back in my part of the country where I was working. And it made sense. So, here I am.

Shauna Hermel:

Can you tell us a little bit about what's prompting your look at a lifetime immunity profile?

Thach Winslow:

Okay, well let me back up a little bit. I want to say that the foundation of animal health on a cow calf operation and really any operation, it centers around management. That includes nutrition, that includes genetics, that includes animal husbandry. And that's the key for animal health. We build on that with different products. And so we can enhance productivity, different products, and that may be anywhere from dewormers to vaccines. And as we're talking about vaccines today, some of the most predominant pathogens we talk about are BVD and IVR. And they're unique in that they are both respiratory, i.e. we see those in the feed lot, but they're also reproductive. We see them in the cow, calf operation as well. And so the term lifetime immunity could be a little deceiving. We don't have a product that provides lifetime immunity.

Shauna Hermel:

There's no easy button.

Thach Winslow:

There's no easy button, no. But what we do have is a concept of how to build lifetime immunity in your herd and maintain it. And so we know that modified live vaccines do a very good job of stimulating both branches of the immune system. So that's both the cell mediated as well as the humeral or the antibody side of the immune system. And once you give modified live vaccines, that immune system is now set up for the rest of its life of that animal's life to respond well. And so if those calves that we vaccinate from branding all the way through weaning have gotten modified live vaccines, then they're going to go into that feed lot feeding situation, more as what we would call moderate or low risk animals, and there's other factors obviously, transportation and things like that. And therefore there's going to be less sickness.

Shauna Hermel:

You bet.

Thach Winslow:

And less sickness means better performance, better performance and less use of antibiotics and all the things that we want in regards to that animal performing. But then we also have in that herd those calves that are coming back around into as our replacements.

So we are developing our heifers and maybe raising bulls. And what we have understood for a long, long time is that heifers with a modified live vaccine, we can have decreased fertility, but even the cow herd through some of the work that Perry has done-

Shauna Hermel:

That's Dr. George Perry?

Thach Winslow:

Yes, we have seen a decrease in conception rates when modified live vaccines are used too close to breeding. And so while that used to be the gold standard for immunity was modified live, the research has been done to show that if they have a modified live foundation, we can booster them with a killed vaccine and that killed vaccine will provide the immunity we want through that next breeding season, while avoiding that unintended consequence of decreased conception rates. And we're talking about $29 a ahead in money recovery there.

Shauna Hermel:

Is that based on product cost or is that based on the number of calves that you would?

Thach Winslow:

So that's both. The majority of that $20 is based on open cows, having less open cows, because when we use a killed over modified live, that first heat conception is 6.5% higher.

Shauna Hermel:

6.5%?

Thach Winslow:

Yes. And the overall conception rate is about two, 2.5% higher. And so not only are we getting more cows bread, but we're getting them bred earlier so that the remaining part of that money, so roughly $4 a head that comes from increased weaning weights because we have older calves. We're weaning an older calf. It had longer time to grow. So at $29 a head using a killed vaccine over a modified live is, that's your benefit. How can you do that? Can we do that with a strictly killed program? No, we need that modified live foundation. And so that's where we get into this lifetime immunity. And so at Elanco we kind of talk, we say, "We want to use the right products in the right animals at the right time so that we can build and maintain a lifetime of health and productivity."

Shauna Hermel:

Excellent. So what are some of the things as you go through a vaccination program, and we know that delivering the vaccine at an ideal setting accomplishes what we want it to, but there are things that we can do that minimize the vaccine. If we leave them on the dash, the vaccine on the dash to the pickup, we can't expect it to work as well. What are some other things that producers need to think about as and maybe with a killed product versus a MLV product as well?

Thach Winslow:

So I love that question because I used to say that the only thing worse than not vaccinating an animal is to vaccinate them thinking that it's going to work, but it doesn't, right?

Shauna Hermel:

Yes.

Thach Winslow:

That false confidence that we have. So you want to make sure that you're purchasing your vaccines from a reliable source. You know that they have been properly manufactured from a company with a good reputation. You know that they've been handled well, stayed under refrigeration. And then when it comes to at the farm level, if it's a vaccine, you have to mix, don't mix them all up at the beginning. Mix them as you use them. Keep them refrigerated. What a lot of people don't, but don't let them freeze. So don't put that bottle on ice, on an ice pack where it might freeze. What a lot of people don't realize is that sunlight can damage vaccines. So keeping them in a cooler, keeps them out of the sun, keeps them refrigerated. Don't mix vaccines. There are some things in one vaccine that may destroy things in another vaccine. So make sure that the syringes you use, that you clean them properly, typically just with very hot water is the best way to clean them. And then an approved lubricant for the barrel, and then make sure that you're administering them properly.

Shauna Hermel:

Now, as you go through and you start those [inaudible 00:09:14] and your vaccination protocol, when are you starting? What age are you starting with that MLV vaccine?

Thach Winslow:

Now we're getting into protocols, and I could write one that I thought would be good for the whole country, and 99% of the time I'd be wrong. Because depending on region and depending on the operation, and even within an operation, we may have a different protocol for a registered herd than we do for a commercial herd. So even on the same farm, in the same county, on the same land, we may have two different protocols. And so that's where it is so critical that you involve a veterinarian, a herd health consultant, have a team to work with you to develop your protocols and a nutritionist, and then you can figure out when the best timing is.

Typically, some calves get vaccinated at birth. The more common is at branding or what we call spring turnout in some parts of the country. And then calves are handled midsummer, which oftentimes they're not accessible, but when they are, it's a great opportunity to give a booster vaccine, maybe to throw in an implant, maybe a midsummer de-worming. So that may be a good time to do that. And then as we get into pre-weaning and weaning, those are very critical times for vaccination.
As we jump around into the end of the breeding herd, then the most common times to vaccinate are going to be pre-breeding and then at preg check. And maybe a third time if it's not combined with at preg check for a scours vaccine, pre-calving.

Shauna Hermel:

Now, as we look at things on vaccinating the calves with an MLV vaccinate, what risk does that pose to the cow? Are we going to cause any reproductive issues there?

Thach Winslow:

That's an excellent question. And there are no modified live vaccines that I'm aware of that are approved to give to calves that are nursing cows that have not received that modified live vaccine. And so keeping in mind, this is where is really important to work with your consulting veterinarian. As when I was in practice, I very confidently used some vaccines off label that were very effective. We can't recommend that, but a veterinarian certainly can, and they can tailor that protocol for that operation where they feel that you can get that modified live in in a very safe manner depending on the product you use and when it's given and make that work. But again, that's something that as a veterinarian I can speak to that, I can't speak to that as a general recommendation in this situation.

Shauna Hermel:

We're going into a timeframe where we're expecting that there's going to be a buildup in the cow herds, so people buy in heifers to expand their own cow herds. What do you recommend as far as bringing those new recruits, whether they be an adult cow or a heifer and fitting them into your own system that you have?

Thach Winslow:

Yeah, so biosecurity is a big part of the industry, and that could be as simple as whether you're buying single source calves in the feed lot, or if you're buying co-mingled cattle. On the cow calf operation, if you have a closed herd and you are now going to reach out and start to buy replacement heifers, I recommend that very well what their vaccination protocol is, and maybe even dictate what it should be, make sure they've got at least one modified live. And then buying from a source that has a good reputation. Same time, if you are selling heifers, you want to have that reputation, and part of that is the protocols that you have and what you do. And over time, calves start to become more and more valuable than the market because of reputation.

The other thing that I would say is important, when you're buying outside cattle, update myself, but there's a time where we wanted a brucellosis test and a TB test, maybe we wanted a yoni certified herd. All of those things can be of value, but to me right now, the number one thing on the list would be a negative PI test for BVD.

Shauna Hermel:

For BVD.

Thach Winslow:

Yep. If an animal has is born PI negative, it will stay PI negative, and that test is good for its life. And so it's not something like another disease where they could not have it yesterday and have it tomorrow. So a negative PI test I think would be valuable. But I would again, consult your veterinarian, understand what risk your herd is, and then be careful about what you're willing to pay a little bit extra for as far as the certifications of the cattle you're buying.

Shauna Hermel:

Would you go so far as to talk to the veterinarian of the herd that you hope to buy cattle from?

Thach Winslow:

Oh, I think so. I don't want to get into the trust thing. It's cattlemen. We are probably, we're soft to the earth, right?

Shauna Hermel:

You bet.

Thach Winslow:

And so you tend to trust when the producer says, "I've done this." But if you don't feel comfortable, by all means, verify it.

Shauna Hermel:

Now, you mentioned that giving the MLV vaccines ahead of breeding, if you give it within 60 days, correct, could cause some fertility issues. How about the bulls? We often tell people to make sure that they don't forget their bulls and to provide the same vaccination program for their bulls, that they do their cow herd. Are there fertility issues there as well?

Thach Winslow:

We haven't seen any, no. And none that I'm aware of. But I will say is in general, when I work, very in general, rule of thumb, there's always exceptions, but when we talk about a vaccination protocol for bulls, I say, "Whatever you do to your cows, do to your bulls." Now, there would be a couple exceptions. If you were using a trick vaccine on your cows, you may not do it on your whole cow herd. And the other would be when you're doing a scours vaccine in your cows, certainly the bulls don't need a scours vaccine because they're not making colostrum. But in general, the vaccination protocol for the bulls to mirror what you do with the cows and at the same time.

Shauna Hermel:

Now we talk about starting with the MLV vaccine first and then being able to go with the killed vaccine after that and in the next years, does that wane? Most people keep their cows four to six years, but then we might want to keep them 10.

Thach Winslow:

And absolutely. Longevity is a big part. And as a matter of fact, when we look at those, I'm going to back up in a minute, when we look at those conception rates being bounced up to second and third and fourth cycle, so that's longevity. What defines longevity? It could be the crippled cow, it could be the bad udder, it could be didn't have a calf, but the number one reasons we call our cows is because they don't produce a calf, right?

Shauna Hermel:

Yes.

Thach Winslow:

And so that long, when we start talking about lifetime immunity and the advantage of getting that killed vaccine in and getting those cows bred early, less open cows, most open cows end up getting sold, so that affects longevity. To answer your question, and I apologize for sidestepping out.

Shauna Hermel:

No, that's fine.

Thach Winslow:

To answer your question, once we prime that immune system with a modified live, that memory is there for the life of the animal. So we can come in with that killed vaccine again and again and again, and get the same strong immune response, and we don't have to come back five years later and throw another live in. We can continue on with that. And I need to be careful. Have we done the herd work to show that in a controlled study? No. But all the evidence that we have points that direction.

Shauna Hermel:

Is there anything that we haven't covered?

Thach Winslow:

Couple things, maybe. One is that I didn't talk about mannheimia vaccines. Mannheimia vaccines are important. There's a long history behind mannheimia, which is the old pastoral haemolytica. At one time we actually had a live, and it probably just caused disease, and then we worked through where we had some vectrens and there's a ton of endotoxins, and that knocked those cattle pretty hard. We have evolved where the best vaccines out there now aren't even using mannheimia to make the leukotoxin. We know leukotoxin is key, but they're not even using mannheimia. So through recombinant DNA, we're able to use E. coli to make the leukotoxin that's necessary for that vaccine, making that a cleaner, smoother vaccine.

Shauna Hermel:

So is mannheimia related to E. coli or how does that-

Thach Winslow:

Nope, that's just part of genetic engineering. That's the magic that the bacteriology guys do. They splice the gene into the E. coli and now it starts making leukotoxin.
There is going to be people who use mannheimia vaccine and their cow herd and not, but typically when you're preparing those calves for weaning, that's where your risk is and whether you're selling them or keeping them and so having a good mania vaccine in there is important to you.

Shauna Hermel:

As calves are approaching weaning time, what products should producers be thinking if they're planning on selling those calves as feeder calves?

Thach Winslow:

Okay, so I'm going to go out on a limb a little bit here because I really believe in the right products, in the right animal at the right time. So as we pick antigens, calves should be well vaccinated with a black leg vaccine, or that's your, say black leg, a seven or eight way cluster radial, that's better, technically correct, with an IBR vaccine with a BVD type one and type two vaccine. And with the mannheimia vaccine, that's my baseline general recommendations. Because I only want to put the antigens in that I think we're going to benefit from, because I don't want the immune system to be paying attention to antigens that aren't important. So I would challenge the industry that we see little to no PI three and why are we vaccinating? And one might say, because we've been doing it forever, and that's what we found 50 years ago.

IBR, PI three, BVD, BRSV, histophilus and mannheimia and pasteurella. And so we make those vaccines, but we're starting to learn what's really important and what isn't. I would argue that there are cases where BRSV vaccine is not necessary. And so the list that I gave you doesn't include some of those. That being said, if I'm selling on a value added program, and that program says in order to sell on our sale, they have to have IBR, PI three, BVD, BRSV, PI, you put those products in because you're going to get a premium on those calfs for doing that. But I challenge, I'm not going to say what's right or wrong, but I challenge the industry to look at what products they're given and are they truly benefiting from those because the old adage, "Oh, it can't hurt," is not true.

Shauna Hermel:

So now with your position in the industry, you have a way to monitor some of the diseases that are becoming more or less prevalent in the feed lots. Is mannheimia one of the diseases that is becoming more prevalent?

Thach Winslow:

Mannheimia is probably just holding his own. Some may say it's dropping off a little bit, and that would be maybe not in numbers, but as a percentage basis because what we are seeing is more histophilus than we've seen before. And so that's probably one of the biggest changes that I've seen in that regard.

Shauna Hermel:

Okay. And I assume with these, you're talking about an initial vaccination and a booster before they leave the farm?

Thach Winslow:

You're talking about, with all the other diseases, yes. Technically a modified live, you can get by with one. It's not a matter of boostering that, but it's sometimes we don't get, in a population, we don't get a hundred percent response. So typically that second round of modified live isn't a booster as much as it is picking up the ones that we missed the first time. Now with some of the mannheimia vaccines and the one that I talked about that is the cleaner of the vaccines that's been made with recombinant, that's a one dose product.

Shauna Hermel:

Can you over vaccinate calves?

Thach Winslow:

You bet. You bet.

Shauna Hermel:

And what are the ramifications to that?

Thach Winslow:

Every time we put a product in an animal, again, there's a cost. When we ask the immune system, and I tell people if they've ever traveled internationally, I've been doing mission trips to Haiti and I've got a laundry list of vaccines, they don't give them all the same day. And when I get one, I know it. And so is there a cost to a vaccine? Absolutely. So again, it's the right products in the right animals at the right time. Nothing more, nothing less. Do we always know what that exactly is? No. And so you hedge on the safe side. If you're not sure, yeah, you probably give that other dose. But when we know, the more we throw at them is not the better.

Shauna Hermel:

And that cost shows up in both product dollars out of your product, but then also maybe some performance?

Thach Winslow:

Dollars out of your pocket. And definitely performance. Yes.

Shauna Hermel:

Thank you for taking time with us.

Thach Winslow:

No, thank you very much.


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