Breeding soundness exams are crucial
Published on March 21, 2020
Many factors play a role in bull fertility and breeding ability, so it is important to make sure every bull has a breeding soundness examination.
Breeding soundness exams look at five key factors – physical soundness, reproductive tract soundness, scrotal circumference, percentage of sperm cells that are normal and acceptable motility.
Even if a bull was fertile in previous years and sired a lot of calves, he may have a problem the producers are not aware of and should be checked again before the breeding season. Some problems and injuries are not obvious until the bull is evaluated by a veterinarian.
Dr. Brian Shoemake of University of Missouri says a breeding soundness exam (BSE) for bulls is one of the most important tools to utilize in a breeding operation. “It’s a good way to assess the bull, with opportunity to closely examine feet and legs, eyes, teeth and body condition, as well as reproductive organs,” he says.
Breeding soundness exams
“With virgin bulls, we can identify any anatomical abnormalities. We examine the penis, scrotum and testicles, to see if there is anything that might inhibit this ability to breed cows,” he says. “We want to find any problems before a bull goes into the herd, so this is a major part of the BSE.”
Shoemake continues, “We also assess the accessory organs that play a role with ejaculation and getting the semen into the cow’s reproductive tract so conception can actually occur.”
Making sure all the bull’s reproductive organs are healthy is important.
“We may find diseases that are treatable and may delay the bull’s breeding ability until later,” says Shoemake. “Some problems are treatable, while others are not.”
Scrotal circumference is measured, especially on young bulls, to make sure they meet minimum standards.
“There are some breed requirements, but we generally follow the American Society for Theriogenology recommendations,” Shoemake explains. “As long as the scrotal circumference is adequate by those standards, it meets our expectations for a breeding bull.”
A semen sample will also be collected and evaluated during a BSE.
“One of the drawbacks of the BSE is we are only assessing semen quality, making sure sperm are motile, with abundant numbers and that their form and structure are normal as well,” he says. “We are only examining the semen, making sure the sperm are capable of fertilizing an egg and not libido.”
“A bull might have exceptional semen and be very fertile, but not have much sex drive,” says Shoemake. “That bull might not breed enough cows.”
He notes some producers might consider using low-libido bulls for artificial insemination, rather than for natural service.
“Since libido is heritable, this is not a good idea if we plan to keep sons or daughters, since their reproductive success might also be questionable,” he stresses.
“One thing producers need to understand is we don’t actually fail or pass a bull on a BSE,” Shoemake explains. “The bull is either satisfactory as a potential breeder, unsatisfactory or deferred until a later test if we find something we need to treat.”
A young immature bull may also be deferred until a later date to check again.
“It’s not that one unsatisfactory BSE fails a bull for life, it’s just at that particular point in time we don’t think the bull will actually be able to do the job,” says Shoemake.
“We typically recommend getting the BSE done at least 30 to 60 days prior to the start of breeding season,” Shoemake says. “Then, if there is something wrong, there is still time to find and acquire a replacement bull, but not so far ahead of breeding season that a lot could happen to change the bull’s status.”
“The BSE is only accurate for that point in time,” he says. “It needs to be done annually and before each breeding season. Ranchers planning to have both fall and spring herds should test prior to each breeding.”
“We need to make sure he is still fertile and sound,” according to Shoemake. “We don’t want to find out later he didn’t settle his cows. The cost of a BSE is very minimal compared to the loss associated with open cows.”
“After a BSE, we know whether or not a certain bull is normal and has the potential to still be good when we need him,” says Shoemake. “It’s a small investment when we consider a bull might be covering 30 to 40 cows, and those calves may be worth somewhere between $600 and $1,000 per head.”
He continues, “This makes the cost of a BSE insignificant. That cost will vary somewhat by region, but usually somewhere between $50 and $100.”
One thing that may not be part of the standard BSE test, but is recommended. Some states require this.
“The perfect time to take a sample for the test is while doing a BSE, since we already have the bull in the chute,” he says. “Depending on the bull buyer’s biosecurity plan, we may also do other screening tests at that time, especially for a new bull, such as tests for bovine viral diarrhea or Johne’s if these tests have not already been done.”
Making sure a new bull is not bringing in a new disease is important to the health of every herd.
Heather Smith-Thomas is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org.