Bull Breeding Soundness Exams and Considerations for the Breeding Season


Hello, we’re going to be discussing the usefulness of breeding soundness examine for bulls particularly for heifers prior to the breeding season. The reason this is important is we want to make sure that our heifers get pregnant early on in the breeding season so they can calve early on in the calving season to be able to get rebred again the next breeding season. This is especially true if you’ve synchronized your heifers. You’re really going to need a bull that is capable of getting all those heifers bred when they start cycling and the ones that are going to recycle after being AI that first time. But what a BSE or breeding soundness exam does is screen a bull to determine whether it’s a satisfactory or an unsatisfactory potential breeder. That is only a part of what is we call the true fertility of getting a heifer bred? But this is one of the things that we can measure and can control by determining whether or not that bull is a satisfactory potential breeder. So other things that are important for a fertility of a bull and heifers is the physical capability of that bull to be able to get around and breed those heifers. The sperm quality and quantity that’s what we all have a specifically measure in the breeding soundness exam is the sperm quantity. Other things go in fertility is the sex drive of that bull, the social rank so we can have a very fertile bull that if socially he is not able to breed heifers he’s not going to be able to get the job done, and then lastly the cyclicity of the females. We can have a extremely fertile bull but if the females aren’t cycling or receptive he’s not going to be able to breed those. What BSE don’t is they don’t predict fertility. We can use them to identify either a sub fertile or an infertile bull, but anything that we can classify as being a satisfactory potential breeder is fertile but there’s big large range of what that fertility may or may be, and so what BSEs really do is identify the substandard ones and not classify one bull as being better than another. Another thing that’s important to remember about a breeding soundness exams is that it’s only valid at the time of the test, so things can happen as those sperm mature in the scrotum. Things can happen to that bull that can change that so just because he had a good BSE last month before though he was turned out if something happened in that 30 days he can no longer be fertile bull a at that time. Some things that go into a good breeding soundness exam besides just looking at the sperm is a general physical exam, the reproductive exam, and then finally to actually look at the sperm and determine whether or not that sperm is of good quality and quantity. Some of the thresholds that we use for determining whether or not a bull is a satisfactory potential breeder is the scrotal circumference of the testicles. Recommended for at least a 15 month old bull those be 30 centimeters or more for his circumference. The motility of the sperm, at least thirty percent of the sperm need to be progressively motile means moving forward in and able to to move and travel through that uterus if once they get deposited, and then seventy percent normal morphology meaning that they’re normal quality.There’s no broken tails, there’s no abnormally shaped heads, no things like that that are going to impair the fertility of those sperm. Again some of the things that we need to look at besides just the sperm are the physical exam. So we want the bulls to be in physically fit and in working condition, So we don’t want them overly fat.These bulls are going to need to be able to work, so they need to be in good shape. But they’re also, if they’re working hard, can lose 100 to 300 pounds so they need to be in good flesh. You know probably it at least a five but probably better to be a body condition score of six or seven, so they can get through that breeding season and lose a couple hundred pounds during that time. Their mouth needs to be in good shape. We don’t want any broken mouth bulls. We don’t want any lump jaws and things like that.These bulls may not eat a lot, but when they do eat they need to be able to eat as much as they can and so if we have any mouth problems they are going to lose weight and are not going to be able to keep up. The eyes, if they’ve had a pink eye lesion in the past that can impair their ability to get around. Bulls are very visual in identifying heifers in heat and so if they have some bulls that are blind or have a hard time seeing they’re going to have a lower ability in order to identify heifers in heat. Feet and legs, these bulls need to get around.They’re going to have to follow these heifers around pasture, so we need to make sure they don’t have any obviously lameness issues. A stifled bull, chronic arthritis, or foot rot or something like that, but other things that may also lead to that a interdigital firbroma between their claws or a screw claw they may not be severely lame now, but trying to get around a pasture those can sure be problems in the future. So make sure that all the bull’s feet and legs are good and sound and they’re going to be able to move once they’re turned out. Finally that leaves us with the reproductive exam, so we again predicted for older bulls we want to make sure that everything is normal there they haven’t had any laceration or something like that in the past that’s going to impede the reproductive organs. So we want to take a good look at the prepuce and make sure there’s no scars, lacerations, hematomas, or those types of things. Make sure there isn’t a hair ring around that penis that’s going to make it painful for the bull to breed a heifer. You can you sort for firborpapilomas or warts on that penis that can impede that. And then finally take a look at the scrotum, we need to have some normal shaped testes. Coming out of winter we can have some issues with frostbite and those types of things that can cause some problems, so we want to make sure that those testes are normal, so he can produce good quality sperm. In summary, when getting ready to send heifers out to pasture to the breeding pasture doing a breeding soundness exam on your bulls is one step to that to make sure that we’ve got a fertile bull that we’re putting out there to get these heifers bred. Particularly, if we’ve got a group of synchronized heifers that are going to all be coming back into heat on about the same day we really need a bull that’s capable of getting all those cows or heifers bred in that short amount of time. And that’s again if we’re going to keep this heifer in the herd for a long time we need to get those heifers bread early on in the breeding season, so having a very fertile bull is going to be key in order to get that done. So thank you and wish you success in your breeding season with your heifers.

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