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A
Hi, welcome to BCI Cattle Chat. I'm Brad White. Happy to have you with us and happy to have our crew here in the studio.
B
Morning, Philip.
C
Good morning, guys.
A
Bob.
B
Hello, everybody.
A
And our special guest, Adrian, who is a member of the Select Sires member cooperative and she's joined in a sponsored by Estrotec. Good morning, Adrian.
D
Good morning.
A
Happy to have you with us. You've been with us before a couple years ago, but tell us a little bit about you.
D
I'm an independent contractor for Select Sires member cooperative. So I breed quite a few cattle every year out here in Oregon. And then I have a small herd of simmental cattle and then do a little bit of teaching.
A
Awesome. And we're glad to have you with us. And we are going to talk about repro today. We're going to talk about awesome.
B
It's always a good day.
A
It's pops favorite day. So we'll talk about estrus expression and then we'll talk a little bit about estrus synchronization programs. And there's some. A lot of protocols out there. So I want to talk about if you're experienced or inexperienced, what are some of the pros and cons? What are some of the things you look for? As always, if you have listener questions for us, you can send us an email@bcisu.edu. we appreciate those questions or comments. Before we get into the discussion today, you guys will notice Dustin is not here this morning, and I don't know if this is a coincidence or not, but he had a suggestion for the starter question, and he said you should ask the podcast crew if they've had any experience with skunks.
C
You think maybe that's why he's not here today?
A
I'm piecing together the puzzle on my own, but I wonder if anybody has any good skunk stories. And Bob, I know you do.
B
You have dogs. You have skunk stories. I mean, how can dogs be so dumb? I mean, they're supposed to have a
A
good sense of smell.
B
They cannot learn this lesson, though. They get taught the lesson and then they forget the lesson.
A
So you'll have to tell us your skunk story.
B
There's like seven of them, and they're all the same story. The dog gets all excited, sees something under the shed or something like that, and he has to go 100% after it. And then he comes boiling out of there, not smelling good. And then my wife seems to think it's my fault and so that I'm the one that gets to try to clean him up, you know, and all that really does is it kind of beats the smell down just a little bit, but it's still there.
A
It doesn't help it. Philip, do you have any good skunk stories?
C
No, but kind of the same as Bob the dog got into skunk. I mean, when I was growing up, we lived out on the farm and stuff. Sometimes the skunks would be up there. They'd come up close to the house, and so, like, yeah, the dogs would get it, and you just have this smell lingering around the yard for several days. I have never been sprayed. My dad used to tell a story that he. When he was a kid, he went out to the chicken house one time and there was a skunk and he got sprayed and had to try to take bath in tomato sauce or juice and all that kind of stuff to try to get rid of the smell.
A
Adrian, do you have a skunk story?
D
Yeah, so I actually have a very friendly cow, and she always comes over when you go feed to, you know, get a scratch. And she had gotten herself skunked because obviously she's very curious. And then she wanted her normal daily pet, and that was not great.
A
Yeah, no, thanks. I. I wonder. You guys all had one right off the top. Our family got together for dinner last night. We were sitting around, and somebody brought up possums, and we all had a possum story. And I don't know if that's one of those. You might be a redneck if you have a poss and skunk story for every occasion.
B
Yeah, good old family reboot.
A
Our family fell into that trash.
C
It might depend on whether that story
A
involves eating the possum. True, there may be some dependency there. So let's talk repro. And I want to start out by talking about estrus expression. And, Bob, I'm going to start with you, and then we're going to get some input from Adrian here. But for years, we talked about heat detection, finding heats, and. And now we're actually starting to talk about the potential, the intensity of those heats, especially as we use timed AI programs. And what does it mean when people are putting that together and saying the intensity of heat expression? And then I want to turn to Adrienne on where she's done some work in that area.
B
Well, you know, I always like to answer a different question than you asked. I know.
A
That's why I don't even bother to come up with a good question, because
B
to me, there's a couple of things. One is even the timing, you know, when we first started coming out with some synchronization protocols. We didn't attempt to do breeding by appointment or timed insemination. And so it involved several days of estrus detection. And it became really obvious that, you know, the heifers and the cows don't read the textbook, and they come in over a pretty long range of time. Now, with some advancements in the protocols, we got that down a lot tighter. And that's when we really, you know, the timed insemination protocols became by far the norm. But remember that those cows and heifers don't read the textbook, and they don't all come in at the same time. And so as, again, these protocols continue to improve, there's a couple of things. One is the timing. And we recognize that maybe we can adjust these protocols a little bit for those heifers or cows that are a little bit behind the rest of the herd as far as when they express estrusion. And then the estrus intensity is an area where a couple of papers, including Adriana, have looked at the intensity. And again, you kind of go back to the old days when we bred off of estrus all the time. And it was obvious that, you know, yeah, some of them have much, you know, expressed estrus much more intensely. It was easier to figure out, you know, should I breed her or not? And some of the others, you were kind of scratching your head trying to figure out the timing.
A
Well, it could be driven by hormone levels, a variety of things. Adrian, what's been your experience with this?
D
I like to tell people that the stronger the heat, the stronger the follicle, you know, more estrogen. So they're going to be showing that estrous activity intensity better. And then that's what's building you a better corpus luteum, which is, you know, going to affect how your pregnancy rates are. So I think a lot of it is just kind of being able to read what's going on in the cow. And luckily, we have a way to kind of see that from the outside.
C
Yeah.
A
And I think that's one of the challenges when we talked about. And I started with heat detection, because I can remember going through training with heat detection, and you're looking at the sexually active group in the pen, and you're trying to figure out who's in heat and is she really in heat. And at that time, you weren't doing a lot of timed, fixed time AI, so you'd try to pick out the one, and then you'd use the AM PM rule, which. Why did that rule exist, Bob?
B
Yeah, really, there's. There's several steps that are important to get a good fertilized egg. One is the semen has a longer lifespan than the egg does. And the semen, actually, the moment it enters the reproductive tract of the female, is not quite ready to fertilize that egg yet. It has to go. It takes several hours to do what's called capacitation, to become ready to fertilize the egg. And so when you start figuring out, okay, when do cows typically ovulate relative to when they start showing estrus, and how long does it take that sperm to capacitate, and how long will the sperm live? And you put all that into your thought process and you come up with, it's about ideal, usually if they'll read the textbook, to breed the females about 12 hours after they're first detected in estrus. So that's where that AM PM rule. And it's a good place to start.
A
So, Adrian, does that fit in with your. As you talk about intensity of estrus when we're watching, it takes a significant amount of time that you'd have to be watching, and it's hard to gauge intensity. How are you measuring that if you
D
are just heat detecting without any, you know, patches or markers or anything like that? You're watching for this, the secondary signs of heat that preclude the standing heat. And then by adding in estrus detection aids, you can start seeing when they were actually standing to be ridden by another cow. Because that estrus detection patch is going to progressively get more and more burnished off. Yeah. It kind of allows you to say, maybe she just started, or, man, that thing's burnished off. She's been standing for a while. And if you're not out there, you know, looking at your cows every hour or so, then it helps you pinpoint that to then time your AI after that.
A
Yeah. So the tail head patch where another cow has been riding her, that'll get more and more intense, give you an idea of how many times she's been ridden. Am I understanding that correctly?
D
Yeah, yeah.
A
So then relative to that, when would you want to breed her? Do you still follow the AM pm, or do you use that as a part of a timed AI program or tell me more.
D
It depends. So if you're doing a timed AI program with a large group of cattle, you're not individually checking each cow, you're depending on a patch to tell you who is in heat at certain time points. And so those are the ones that you can can go ahead and breed, but by using the synchronization, you essentially started a timer that you can can work off of. If I'm working off more of just a singular cow or a couple cows that are coming into heat, I shoot for that 12 hours still. But really I say 8 to 16 hours, depending on how much you've seen the cow and then how, you know, how well rubbed off that patches and then if she's done showing signs of heat.
A
Well, and I think that makes sense because some of the decisions that I may make even in a timed AI program are do I put in sexed semen in this cow, which would be more expensive and have a little bit lower chance of conception anyway, or do I put a cheaper semen in this cow that maybe isn't quite as in, as good of a heat? Philip, I know you had a question.
C
Yeah, I got a couple questions for you, Adrian. Kind of are there factors that I guess, kind of that you see associated with these high intensity heats? Is it more prevalent in heifers versus cows? Or maybe I should say the other way, cows versus heifers, is it more prevalent, if we're looking at heifers, is it more prevalent in my older, heavier heifers, are there some factors associated with that animal having a more high intensity heat or does it seem to be just kind of random?
D
Yeah, no, absolutely. Nutrition is your number one factor with your reproductive success. If you think about it, you know, all those reproductive hormones are steroid hormones and built off fat. And so if you have a heavier, fatter heifer, you know, within a healthy range, those are going to be the ones that are cycling and expressing heat and expressing good heats. Um, heifers will definitely show you more heats than cows because they just really don't have anything better to do besides eat and run around. So, you know, those cows, you're asking a lot more of a cow because she's nursing a calf and she's still recovering from that, that previous pregnancy. So she may or may not be cycling. So that's the other thing is that some of those cows are kind of on that edge of that anestrus, you know, starting to cycle again after calving. So you're just asking a lot more of a cow, especially like a first calf heifer that's had her first calf and that breeding back the second time is actually the hardest one to achieve pregnancy.
C
So in those heifers, if you're seeing it more, does the development program of those heifers make a difference in the intensity of the heat. So let me give you some scenarios. Say like there's some development programs where we kind of grow the heifer pretty slow for a while and then like two or three months before breeding season, we really push her and get her to gain a lot and gain quickly in the last few months. And there's also some, some work done in Nebraska where, you know, they, they kind of grow them slow and then when they turn out on green grass, they get a flush there and they get a good breedup. Even though those heifers are a little lighter and they don't, they haven't really reached what we would consider that 60, you know, 60% immature weight or whatever. And so does that program influence that even if they are in pre good body condition score, does the way they got there make a difference?
D
I'm sure it has some difference and I know I've read a few articles on that. But again, I have seen a lot of stuff done that you can be breeding heifers at 50 to 55% of their mature body weight. I think a lot of it has to do as long as they're on an increasing plane of nutrition and it's adequate.
A
Excellent. So as you guys mentioned, there's several things that influence that intensity of estrus, the success of the program. And one of the things relative to understanding the intensity of estrust is not just which one should I breed or not breed, but probably if you're making the decision what type of semen do I want to put in? So it's sex semen or some of the other semen, but that's all dependent on our estrus synchronization program. And I want to talk about maybe some keys to success. And there's a lot of synchronization programs that are out there that the Beef Reproductive Task Force, if you google that online, you can come up with a whole list of protocols. And I want to talk through maybe some of the specifics and some of the broad terms of what makes for a successful estrus synchronization program if I'm going to do that on my herd. And Adrian, I'm going to ask you if you're. I'm a new herd, I'm coming to you and I say, hey, I want this to be successful this year. What are some of the key questions you might ask me?
D
Well, the first thing I talk to them about is planning it and scheduling it. And hopefully they're talking to me several months before we're trying to breed these cows, Not a couple weeks before. Because a lot of it is setting those cows up for success and setting yourself up for success and being prepared and your facilities. You know, first questions we're asking is when do you want to have calves? Because that's going to dictate when we're breeding. And then, then you have to back up before that breeding date. And you need to start talking to them about feeding, vaccinations and minerals. So those are kind of the main touch points that I go over when I'm talking to a new client.
B
Yeah, I think it's fun to actually work with a client that hasn't done this before. And one of the things I really like to do is, you know, we start with age and weight. So I want the heifers to be old enough. I like early born heifers. If I'm pulling them out of that same herd or if I'm purchasing heifers, they need to be old enough so that they're very likely to have reached puberty by the time we want to start this breeding program. And there's a target weight. And again, there's honestly different strategies for how to, how to hit the target weight and what target weight we want. But then especially if it's a herd that I have not worked with before, I really like to go in and do a pre breeding exam. And that's where we use information like the weight and age. But we'll also palpate that reproductive tract, both the uterus and the ovaries. And we're trying to gauge on a group level what percentage of those heifers have already reached puberty. Because there's both a question about individual heifers, but there's also a question about, well, the management of the group. Is it really setting those heifers up for success? So I've become a real big fan of evaluating the group before we start the synchronization protocol to make sure that we're going. It's basically a way to ensure that we're probably going to have good success versus being surprised later. Oh, a bunch of these heifers hadn't reached puberty yet.
A
Because the problem is later can be much later.
B
Right.
A
If you don't do any estrogen detection and you breed them on fixed time, AI later could be at preg check. You have a very unpleasant surprise. If you know that going in, you potentially could modify the program, modify the course. I like your idea of the reproductive track score, but it ties into some of our nutrition, gives us an idea because you do the track Score, you're also looking at body weight, but you want to be sure that they're in an adequate plane of nutrition. Right, Philip?
C
Yeah, well, we talk about body condition score at the time or leading up to it, but you don't want them in a decreasing plane of nutrition at the time of breeding or shortly after because that can affect conception rates. So you want to keep them on the same plane. Or maybe they're. Or where they're maintaining or they're gaining a little.
B
Yeah. And sometimes that can be a challenge if, you know, depending on the herd and the timing. A lot of times that's kind of around, you know, grass turnout time. So we've gone from where having them in a grass trap or a dry lot and develop these heifers. And then kind of at the time of the breeding season is often about the time we're thinking about going to grass. Is there. Is there any problems with that?
C
Well, there could be if you really pushing those heifers and you're dropping off. So you might want to think about, I develop those heifers and then I give myself, you know, a month or something to get them on a plane of nutrition that's going to be similar to what they're turning out to on grass. And so that. That plan of nutrition stays consistent. Although, I mean, you know, grass is. Is obviously different than.
B
Right.
C
Probably what I'm feeding them. So I've. I've got to think through that a little bit, and that that can be challenging, but I don't want a drastic change there when I go from my dry lot ration to grass.
A
So, Adrian, a lot of this, as we talk about nutrition or management, it's pretty different in heifers versus cows. So tell me specifically for the cowherd, if I'm going to use estro synchronization AI program, what are. What are some of the things that I may look at there that's a little bit different in heifers because I don't have as much control over nutrition.
D
So with your cows, you probably are going to need to look more at just kind of like a fat supplementation in that period because they're going to be lactating, you know, at their kind of heaviest right. When you're AI ing them. So that's kind of what I would pay attention to, is assuming that you have adequate forage or hay, but that you're possibly going to kind of bump that, that fat and mineral pack for them.
A
Well, and I think another big thing on. On cows is you you talked earlier the timing of the program. Right. And being sure that I've got enough cows that have calved and gone through their postpartum period so that they're ready, ready to breed back and ready to respond. And some of these different synchronization programs, Bob, that are on this repro task force, they're basically combinations of a couple different hormones, right? We've got a progestin, a GnRH, a prostaglandin, a gonadotropin releasing hormone, a prostaglandin. What makes a program better than another program or work better in different scenarios, right?
B
Well, yeah, basically all the protocols that we have for synchronizing heifers and cows use those same three hormones. The difference is kind of how many times we have to put the animal through the chute. And a lot of times it's a trade off in that some of our more complicated protocols, with an extra step or two through the squeeze chute, we get maybe a little tighter synchrony, but that's the trade off. And so then you start thinking about, well, am I breeding 20 heifers or am I breeding 200 heifers? And so my labor availability, my facilities availability, and just how many heifers I've got. And honestly, I do want to point people to that beef reproduction task force. They've got a lot of good resources, not only these protocols, but some other resources as well. And I would say all the protocols on their website, I think, are good. And so you start thinking about what would work best for my herd.
A
And if you've got further interest in that, we did Bob and I did a Bovine Science with BCI podcast where we dove into the details of several of those programs, picking which ones are best for heifers and which are for cows.
C
Philip, so your question there, and so follow up or, sorry, your statement there about what works best for you. So my follow up to you and to Adrian, looking at these protocols, looks like you're running the animal through the chute anywhere between two and four times to give the injections and to AI that animal. So is that my trade off? If I ran her through the chute four times to get that would. That would allow me to, to give like the perfect estra sync setup. But I don't want to run her through four times. So I'm only, I'm going to use a protocol that only I only have to run her through two or three times. Is that my trade off that I'm going to reduce my success a Little bit because of that.
D
I was going to say that this isn't exactly answering your question, but backing up to what Bob was saying about doing that reproductive track score. If you use that, you can use the 14 day Cedar Protocol for heifers, which actually starts you out ahead, a month ahead of your breeding. And that allows you to combine one of your trips through the chute with reproductive tract scoring, you know, body condition scoring. You can actually do your booster vaccines and then you also can maybe change, you know, push the needle a little bit on, on nutrition if you need to. It also spaces out those trips through the chute. So. So they're about two weeks apart. They're not quite as sour on it. So I think that is a good one to use for heifers and also to start people out on as long as you have that time ahead of time. But like I said, you're combining those trips to the shoot so it lowers the bar a little bit.
B
Yeah. And I'm not ready to say how much some of these protocols differ in their success. They're all going to be pretty good. And so I will kind of agree with you the more times that there's through the shooting. Really what I'm trying to do is make my timed insemination more successful. Now I like actually I'll give a nod to like estratech when we add some additional information. So we actually have an idea based on some sort of a patch or electronic mounting counter that actually adds another piece of information that allows some flexibility. But now it's no longer this, that pure timed insemination where all the heifers are inseminated at one time point. I'm actually out there for it's a longer day or a couple of days to get heifers bred. And so it's a trade off with labor. And how many total heifers or cows do I get bred from this protocol? So I'll stick with my answer of I need to really understand what the producer is willing and able to do labor wise and what their real goals are. And we're not talking about night and day differences in the breed up of the heifers, but it's enough to make some for a lot of people. It's enough to justify the extra work.
A
And I'm going to argue a trip through the chute is not a trip through the chute at every operation.
B
Oh yeah, that's easy and quick.
A
And where you are sometimes a trip through the chute is a walk through the park. Sometime a trip through the chute you've
B
got a story where geese are involved and it's not good.
A
Yeah exactly. So it can be a real challenge and and those things and we're making light of it but that impacts it. Right. If you say if four trips through the chute is all hands on deck experience that could impact your breeding rates. If four trips through the chute is a couple people and walking through pretty casual that impacts because that stress on
C
that cow when she gets stressed that's
A
going to negatively impact that's what we care about more than necessarily just times through the chute is what is the impact to that and I think some good keys to which ESTRA synchronization programs may work or not how you would implement those A great discussion on reproduction today Adrian appreciate you joining us And Adrian was sponsored by Estrotect so I think a great way to jump into breeding season. If you have more questions on these reproductive profiles there's information online or of course you could always send us a question@bcisu.edu.
Podcast: BCI Cattle Chat
Host(s): Dr. Brad White, Dr. Bob (likely Dr. Bob Larson), Dr. Philip, and guest Adrian (Select Sires Cooperative)
Sponsor: ESTROTECT
Episode Theme: Estrus Expression, Synchronization, and Reproductive Success
Date: March 6, 2026
This episode focuses on reproductive management in beef cattle, with a special emphasis on estrus expression, estrus synchronization programs, and the practical considerations cattle producers face to improve reproductive success. The discussion features insights from the BCI team and guest Adrian, an AI technician and educator from Oregon with extensive experience in selective breeding and cattle reproduction.
Skunk Stories Icebreaker (02:08):
"There's like seven of them, and they're all the same story. The dog gets all excited, sees something under the shed or something like that, and he has to go 100% after it. And then he comes boiling out of there, not smelling good." – Bob [02:08]
Estrus Intensity Insight (06:10):
"I like to tell people that the stronger the heat, the stronger the follicle, you know, more estrogen. So they're going to be showing that estrous activity intensity better. And then that's what's building you a better corpus luteum, which is, you know, going to affect how your pregnancy rates are." – Adrian [06:10]
AM/PM Rule Explained (06:58):
"So when you start figuring out, okay, when do cows typically ovulate relative to when they start showing estrus, and how long does it take that sperm to capacitate, and how long will the sperm live?... it's about ideal... to breed the females about 12 hours after they're first detected in estrus." – Bob [06:58]