There are a lot of reasons to consider replacing a bull; the most obvious one is if he can’t get you calves.
“Anytime there is a bull fertility issue that leads to not getting the cows bred, you need to think very seriously about getting rid of the bull,” Andrew McCorkill, University of Missouri livestock specialist, told Ozarks Farm & Neighbor. “That is what pays the bills.”
He recommended a proactive approach prior to turning the bulls out, by taking them to the vet’s office for a Breeding Soundness Exam.
The BSE doesn’t just look at sperm quality; it also examines other aspects of the bull’s well-being, like its ability to get around and to mount. “One of the more common reasons a bull gets culled, other than age, is feet and leg issues,” McCorkill said. “Sometimes it is the result of skeletal structure issues that slow the bull down, or feet problems such as a ‘corkscrew toe.’”
It is also a good idea to test bulls for trichomoniasis; the protozoan disease can wreak havoc on a breeding season, leaving you with a very low pregnancy rate and a strung-out calving season. If a bull does test positive for trich, it will need to be culled.
You could also choose to replace a bull that’s performing reasonably well, simply because “reasonably well” isn’t good enough. Check your production records; do calves from that bull grow at the rate you want, or is there something about them that gets them docked at the sale barn? A check of EPDs can help you find a bull more suited to your needs. McCorkill noted, “The Ozarks are full of small farms that only have use for one bull. When it comes time to replace older cows in the herd, many producers choose to take the route of raising their own heifers to keep because they know what they are getting. If that’s the case, it’s time to upgrade bulls.”
Dr. Shane Gadberry, University of Arkansas Extension animal scientist, told OFN your breeding schedule can make a difference in buying a new bull. “If you have a fall confined breeding season, you might be sourcing bulls at a different time of year than a spring breeding season,” he said. “If you procure bulls at a purebred breeder ranch sale, you have to look at which ranches have spring sales versus fall sales, and how they fit into the age of bull that you’re trying to purchase.”
On the other hand, he said there are often more bull offerings in the spring than fall, so you may have to think about making a spring purchase for a fall breeding herd.
You may move a bull so you don’t have to keep him around. “If you have a really tight, controlled 60-day breeding season, then you’re owning a bull for another 10 months out of the year. Just dealing with the maintenance costs of bull ownership for one small, controlled-type breeding season may be one consideration to just turn bulls over more readily,” Gadberry pointed out.
And there may be the need to replace a bull just due to wear and tear. Gadberry pointed out bulls are more active in the cow herd, and are more prone to injury because of that increased activity. “We tend to lean toward a younger bull as a replacement bull,” he said.
“A general rule of thumb that we use with really young bulls is not to expose them to any more females than their month of age. So, you don’t want to expose a 16-18 month old bull to more than 16-18 cows in a controlled breeding season.” One way to get more out of a bull is to have separate spring and fall breeding seasons, so the same bull could service twice as many females without having to bring in reinforcements.
But McCorkill said, “The bottom line is, if the bull isn’t earning his keep, you need to get rid of him. Sometimes it’s a tough decision; anyone who has been in the cattle business long enough has had a bull here and there that were great producers that they hated to part with. But when the time comes that they don’t work anymore because of trouble getting around, sub-par fertility, or whatever the reason, you just have to bite the bullet and go searching for his replacement.”