Better Breeding Bulls
Shaye Koester 00:02
Hey, hey, it’s Shaye Koester and I’m your host for the Casual Cattle Conversations podcast where we connect you to ranchers and beef industry enthusiasts who can help you build a more profitable operation and improve your lifestyle. Are you looking for a community of ranchers who support and challenge you to be more profitable and proactive? Then sign-up for our monthly RancherMind events. RancherMinds are mastermind events for ranchers to come together once a month and find solutions for their own and the industry's challenges. Stay connected by following @cattleconvos on Instagram, Facebook and Twitter and never miss an episode or event update by signing up for our newsletter on casualcattleconversations.com/newsletter. If you get value out of this episode or any episode drop a comment or tip me by using the link in the show notes. With that let’s see who our guest is today and connect you to a new resource to improve your own operation and lifestyle. Alrighty, Folks, today we are going to be talking about breeding soundness exams, and why they're important, what they are and what you need to do as a producer, so that you can make sure that your cows are getting bred. We will be visiting with Dr. Kacie McCarthy about this topic. So with that, let's get on with the interviewer. Thanks for joining me today. It's exciting to get to talk about this outside of class and other research projects and share it with my listeners a little more.
Kacie McCarthy 01:39
Well, I am just really excited to be here and chat with you. I know we've worked together in the past related to the topic. So actually getting to dive in and talk about some of the questions we have today related to breeding, soundness exams, and just overall bull management I think it's going to be a great topic, especially for the time of season that we're moving into, you know, bull season is upon us. So it's really exciting to get our listeners and producers thinking about the topic.
Shaye Koester 02:09
Yeah, absolutely. Bull sale season is now and you know, we'll talk about it more but just important to get those bulls rechecked before they get turned out. But before we dive into breeding soundness exams, how about you talk about what your role in the industry is today?
Kacie McCarthy 02:25
Absolutely. So I am the Beef Cow-calf specialist at University of Nebraska Lincoln. I started here at UNL in January of 2020. So what I get to do is work with students on campus. I've got a teaching appointment, where I get to talk about all things cow-calf management, and then also going to talk to producers on the daily, just about general management, I really like to focus on bull and heifer development, as well as really targeting some of those nutritional and reproductive interactions that ultimately target our cow calf producer's profitability.
Shaye Koester 03:05
Well, awesome. A lot of exciting stuff there. You get to work with a lot of different people, a lot of varying levels of people. So that's exciting. But with that, so we're talking about breeding soundness exams, like we've talked about a little bit in the intro. So what is that BSE? What is that breeding soundness exam?
Kacie McCarthy 03:22
Yep, so a breeding soundness exam, originally has been developed by the American Society of Theriogenology. And so what they have is a set of minimum guidelines, where they're going to evaluate a bull to ensure that he passes that exam. Basically to say he's a satisfactory breeder, you can turn him out, while we're evaluating physical and semen quality, we feel that he is capable of getting the job done. That breeding soundness exam really is a point in time measurement that's going to give us a little snapshot in where that bull's fertility is at?
Shaye Koester 04:04
Well, awesome. So I mean, obviously, we want satisfactory breeders, but I mean, that is a huge value and a huge importance for ranchers to be getting their bulls tested. Because the impact of if you turn a bull out, and all of a sudden, he has bad semen. I mean, that's very detrimental when you look at your fertility rates being lower or open cows, etc, at the end of the year.
Kacie McCarthy 04:28
Absolutely. You know, and so, when we think about this snapshot in time, right, we want to make sure that our timing is important when we're getting that evaluated. And, you know, at the end of the day for our satisfactory breeders, we have a set of guidelines that those veterinarians are going to cover and so what they look at in terms of physical characteristics are they're gonna evaluate feet, legs, teeth, eyes, take a once over on body condition score of those bulls, and then we start to dive into more The reproductive side. And so we'll evaluate those internal accessory sex glands. And so start palpating making sure there isn't any inflammation or damage to some of those accessory sex glands. And then we start to move into a scrotum measurement and testing and palpating the scrotum to make sure there isn't any swelling or damage to those testes. And then at the end of the day, what really counts is that semen evaluation. For a bull to be a satisfactory breeder, he needs to have a 30% progressive motility score and a 70% morphology score. Ultimately, when we think about those two numbers, motility, we want to make sure that progressive is moving in a linear line. And so those bulls sperm are moving, they might be spinning. But at the end of the day, they need to be able to reach that ovacite, right and, and so we need to make sure that they can move through that tract, and get to that target egg to ensure fertilization. And so that's pretty critical when we think about evaluating those sperm characteristics. And then morphology, ultimately, at the end of the day, really is looking at, you know, any abnormalities, any weird tales, distal droplets, really thinking about any major or minor abnormalities that ultimately are going to impact fertility. When we think about some of those morphologically abnormal sperm, these are usually associated with male infertility, which ultimately is going to be fundamental for determining that quality of that semen. So when we can really identify these bulls early, those are usually our most common reasons bulls are classified as unsatisfactory or potentially deferred breeders.
Shaye Koester 07:05
Yeah, and I think, you know, there's a lot of things I'd like to dive into on some of those fronts. But since you know, you just talked about the morphology side now. Is that genetic? Is that something where even if he could get some bred, could he potentially produce future bull calves that would also have bad semen morphology, like what does that look like on the genetic level?
Kacie McCarthy 07:25
So on the genetic level, when we think about just fertility, it's a pretty lowly heritable trait. However, when we think about just looking at defects in that sperm, some of that may be impacted in terms of nutrition, some may be insult or injury during winter that may be impacting that overall maturation of that sperm. So there's a lot that goes into production of that sperm, and ultimately, those environmental and genetic factors that all play a role. And so, you know, for me, we're really targeting and looking at some of those nutritional impacts. But, you know, diving onto that genetic side, you know, if you if you do have bulls that are highly adept to having some issues. There may be some reconsiderations, when we think about overall performance, and semen quality of those bulls, because especially when we think about collecting multiple bulls for AI sires you know, versus maybe natural breeding. A lot of that can get filtered out when you think about defects, or maybe lower quality, semen. But at the end of the day, you want to make sure you are targeting those goals related to some of those genetic markers, you're looking at.
Shaye Koester 08:51
Awesome, kind of taking a couple steps back. Right away. You mentioned your body condition score goals before they turn out what is that ideal body condition score before turnout? And, you know, how does that need to be evaluated throughout the summer throughout that breeding season? Because those boys are working when they're out there? So let's talk about that for a second.
Kacie McCarthy 09:11
Absolutely great question related to body condition. Now, sometimes we forget about our bulls and adding them to our our condition scoring outline or spreadsheet at the end of the day. When we're looking at our cows, bulls are the same kind of beasts where we're targeting that five or six body condition score. You know, we'll have some bulls that are maybe a little flashier, a little on the pudgy side of condition and then we'll have some bulls that you know, are losing some condition a little bit, but the the big target is making sure that their in adequate condition moving into the breeding season. So there's been some work out of Canada and across the states that have tried to really measure what that loss in bull body weight and condition looks like and upwards of, you know, as low as 100 pounds and upwards of maybe three to 400 pounds. There's a pretty wide range in terms of body weight loss during the breeding season. So if we keep that in mind, if we have bulls in a moderate condition, we know that if they're really working and we set our stocking rates appropriately, we're going to have some condition loss in those bulls. During my PhD working out at North Dakota State University I had the opportunity to work with some of our mature bulls, and really thinking about this concept of bulls either losing or gaining weight. What we really started with diving into is, you know, if we get bulls overly fat or a little heavier, conditioned, you know, up in the sevens to eights versus, you know, fours and fives, what does that look like in semen characteristics overall. You know, BSC, when we think about just condition, and those semen characteristics, and so some really interesting data coming out of there, that's been an ongoing study. Definitely I'll include that link for you at the end of the day. But really interesting how we can focus on recovering those bulls, and making sure that we're in that five to six body condition score, because at the end of the day, we do see some changes in semen characteristics based on changes in body condition.
Shaye Koester 11:35
Awesome. Well, and then the other point that you brought up that I want to touch on quick so you said scrotal measurement. So why does scrotal size matter? Why do producers need to look at this when they're purchasing bulls?
Kacie McCarthy 11:47
Yes, so scroll circumference measurements is a component of the BSE. When they're doing that physical exam, they're gonna then check and measure the scrotum. Now, part of those minimum guidelines for our BSE. Bulls need to meet their minimum scrotal measurement based on age. So when we think about scrotum measurements, our 15 month old bulls need to at least meet 30 centimeters in diameter for that scrotum, and then upwards of that measurement starts to increase the older those bulls get. And so once we hit bulls at 24 months or older, then what we see is they need to meet at least 34 centimeters in diameter. Now, there's been some work looking at some of the relationships between scrotal circumference and age of puberty. And there's a high correlation there with scrotal circumference and puberty in both their male offspring or in those bulls and age of puberty in their heifer and their progeny. So that's a great measurement. If you're thinking about puberty and your females, if you're developing heifers, and females for your operation, or maybe others that's a great measurement when we think about fertility and puberty.
Shaye Koester 13:14
Well, awesome. So with that, you know, I think we've really covered the wide array of it and why it's important. So is there any upcoming research on this topic that you're excited about? And I'd like to touch on for a minute or two?
Kacie McCarthy 13:29
Absolutely. So I think, you know, we're working on some collaborations right now at USMARC in Clay Center, the USDA Meat Animal Research Center, where we're looking at yearling bull development. So looking at yearling bulls rate of gain, and those impacts on semen characteristics, and then ultimately trying to follow these bulls through in terms of longevity and overall performance, and how that impacts offspring. And so, with that collaboration, we have scientists from North Dakota State, Cal Poly looking at some behavioral work, we have scientists from Texas A&M Agrilife and then also have some scientists from Fort Keogh and USDA up in Miles City, Montana. So it's a new and maybe, you know, area that a lot of these researchers have really kind of shifted gears to that paternal side of research. What we're really targeting is some of those producer questions of you know, how these yearling bulls are being developed for bull sales and or how should we be managing these bulls at the end of the day when we get them home, and then transition out into that breeding season and subsequent breeding season. So I'm really excited about that applicable research that we're seeing here with this dataset of how can I provide some research based data to producers to say, Yep, exactly how you've been doing it for umpteen years, this is right, you know, and this is how we can make sure that these bulls, stay in the herd. They're successful and we're meeting those markers for development.
Shaye Koester 15:17
Well, exciting stuff. So as we wrap up, let's just kind of quick recap, you know, the main point of this episode, so producers need to get their bulls evaluated by their veterinarian, pretty simple, use that relationship you already have, and about how far in advance again, do they need to do that?
Kacie McCarthy 15:35
Yeah, so when we're thinking about getting BSEs done, we generally recommend four to six weeks prior to turn out that lets you determine if you need to find any bulls, and also is an opportunity where if we did have any injuries or frostbite issues in the winter time, and or maybe we got a really early bull sale, BSC done really encourage producers to take a look at those bulls again prior to turn out. Just because a lot can happen from you know, January, February, March until May, June, July when breeding season is. So usually that four to six week window usually meets a majority of those goals. Alrighty, folks, well, this episode should be coming out in about April. So if you have those bulls, make sure to schedule that with your veterinarian four to six weeks out in advance and make sure you guys can get the cows bred this year. Thanks for joining me today. Thank you for having me.
Shaye Koester 16:36
And that's a wrap on that one. Thanks for tuning in again. And I hope to see on the next one. You have a great rest of your week, folks.
