Extreme Cold Puts Herd Sires In Vulnerable Position
March 31, 2014
Bull sales have been barn burners this spring, with skyrocketing averages and unheard of high-sellers. Selecting a herd sire can be a difficult task, with EPDs, DNA data, performance records and physical appearance to sort through; however, for many cattlemen the excitement of buying a herd sire doesn't always extend to taking care of that investment once he gets to his new home on the ranch.
If buying a bull at a sale, he has presumably passed a breeding soundness examination (BSE); unfortunately, that doesn't mean he will remain fertile throughout his lifetime.
Cole Eldon, University of Missouri Extension livestock specialist, hosts two workshops each year – one in the fall and one in the spring – to encourage area ranchers to get their bulls tested for fertility. These clinics allow producers to come in and have one-on-one attention with the veterinarian who spends the day examining herd bulls.
"Bulls are a large investment and it pays to invest a small amount in the BSE test for insurance that your bull is capable of going out and breeding several cows in a 45-60 day breeding season," said Cole. "Ranchers need to pay more attention to their herd bull. He's a pretty important piece of equipment to have around the cowherd."
In his ninth year of hosting clinics, Cole has observed that 10-15 percent of bulls tested fail or are deferred for a re-test. While Eldon operates south of most of the Tri-State Livestock News readership, where winter weather isn't as extreme, he says the cold weather has been harsh in his neck of the woods, as well, which puts herd bulls in an especially vulnerable position for frost bite.
"Since this winter has been extremely cold, the percentage of failed breeding soundness exams could be greater this spring," he warned. "Frostbite of the scrotum will be more likely than in previously relatively mild winters. Semen, penile or other physical problems need to be discovered well ahead of bull turnout. This allows cattle producers more time to search for a really good bull at the sales or private treaty."
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A BSE is an important test used to identify bulls with a reduced fertility rate, not just to find those that are sterile, as very few bulls are actually sterile, but many have reduced fertility rates for various reasons.
A BSE includes looking at several factors including a physical examination of the bull. A veterinarian will look at the bull's body condition score, feet, legs, eyes, reproductive tract, scrotum and penis. The reproductive tract is evaluated by rectal palpation, and a scrotal measurement is taken, with a 30-inch circumference typically being the lower end of satisfactory. Next, a sample of semen is collected and evaluated under a microscope slide for mobility. A reading of 70 percent sperm mobility is considered a "passing grade." Anything below that would require culling or a secondary test, as the test is only a screen shot of the bull's ability to breed cows.
"Another good thing to do when you have the bull in the chute for a BSE is to give his his booster shot and a dewormer for parasite control," Cole recommended. "We are also recommending folks collect DNA on the bulls, either through pulling tail hair or taking a blood sample. The value of having this information is like looking at 15-20 progeny of that bull; it really helps evaluate the value of the animal."
Another thing to test for while the bull is in the chute is Trichomoniasis, more commonly referred to as "trich," which Cole says is especially important if buying bulls from out-of-state or purchasing a non-virgin bull.
"Testing for trich is very important on older bulls," he stressed. "An owner should test for trich if the bull has been exposed to cows across the fence or is an older bull. Non-virgin bulls absolutely need to be tested. The thing about trich is you can't tell a thing by looking at the bull, but if you have a strung-out calf crop or a period where the bull wasn't breeding, it may not necessarily be the bull's fault. It might have been passed around from the cows to the group of bulls in the pasture. The bottom-line is there are no visible signs. You've got to test to know for sure."
Just because a bull fails his BSE, doesn't mean he's destined to head to town. Obviously, a bull offered in a sale or by private treaty must pass a BSE with flying colors; however, an owner may choose to utilize a bull for his own cowherd if he scores below the acceptable passing grade for the BSE.
"If you have an unsatisfactory bull, it's important to weigh the pros and cons," advised Cole. "Maybe he has a lot of value, and you want to get one more year out of him. It's important to look at why he failed the BSE. Were his hooves too long? Can you trim them up to get one more year out of him? Did he have a penile injury last summer? Is he healing? Can he breed? Is his sperm count low? Does he have a sore on his scrotum? He might be worth giving a second chance, but cows that come up open are pretty expensive to replace, too."
There are several things a rancher can do to protect his bull investment, Cole said.
"First, take the bull away from the cowherd in between breeding seasons," he recommended. "We don't see ranchers doing that as much as we should. Another thing to watch for is a low body condition score. It's important to feed them high-quality hay and maybe some extra corn. This is especially important for yearling bulls that still need some groceries to grow up to maturity. Not to mention, these bulls are costing upwards of $3,000-$4,000 and more, so it's important to take care of that investment."
Additionally, Cole said bulls that are utilized for both the spring and fall calving seasons need extra attention.
"If you are using a bull for both spring and fall calving seasons, they are being put to work," he said. "This helps spread out the investment cost of the bull a little bit over more calves, but it is harder physically on the bull. If he's not being cared for, the negligence will result in problems sooner rather than later."
With the cold winter weather, the biggest way to protect that bull investment is with bedding or some protection from the elements.
"Laying down straw or corn stalk bales might be extra work, but it gives that bull some insulation from the threat of frostbite," he said.
At the end of the day, BSE is a small price to pay for some basic insurance that the bull can do the job.
"If you have bought a bull, you need to know he's going to go out and work for you," Cole said.