Bulls that pack on a few extra pounds may not have the stamina to breed the needed number of cows
Ferdinand, the bull famous in children’s fiction, just wanted to sit and smell the flowers.
With that kind of attitude, Ferdinand wouldn’t be wanted in commercial beef herds. In fact, Ferdinand would sooner find himself in a batch of bologna than in the shade of a tree.
There are several reasons bulls may not be doing the job cow-calf producers want, namely breeding cows and siring healthy and vigorous calves.
Maybe Ferdinand is too fat.
“When you have a bull that’s over condition, he’s just overfat, what’s going to happen is, for the first 30 days of the breeding season, if that is in June or July, all he’s going to want to do is maybe breed a few cows but he’s going to sit underneath a tree in the shade and burn off his fat. He’s not going to do his work,” said Alberta Agriculture livestock specialist Barry Yaremcio.
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“He can have a higher core body temperature than one that’s a little bit thinner, so that may impact the quality of the semen.”
However, a thin bull isn’t desirable either.
“You put a bull out with 30 cows, at the end of a breeding season he’s pretty thin. There’s not much extra weight on him because he’s spending all his time working rather than eating so that can be a problem as well,” Yaremcio said.
A number of factors come into play when deciding how long to keep a bull in the herd. Performance is naturally the biggest factor. Genetic tests can tell producers how many calves a bull has sired, although that can be expensive.
Yaremcio said bulls should be evaluated every year by a veterinarian and checked for overall health and soundness, as well as semen quality and motility.
Health issues that arise after that evaluation must also be managed with caution. For example, foot rot or other inflammation can cause fever.
“That higher temperature will greatly reduce or eliminate the number of live sperm that have motility,” said Yaremcio.
“Even though you may have treated that bull with some sort of antibiotic to get the foot rot down and he’s walking normally and he seems to be jumping and doing his work, he’s shooting blanks for 60 days.”
He advises removing that bull from the herd, either temporarily or permanently.
Bull size in relation to the size of the cows or heifers in the herd is another consideration. They should be relatively compatible in size or injuries can result.
Temperament is another factor.
“Sometimes a bull will get snarky. There’s been too many people injured or killed by rangy bulls. We don’t need that,” Yaremcio said.
A bull’s success in the herd is also greatly affected by its winter feeding program. Bulls need trace minerals — copper, manganese, zinc, selenium, iodine and cobalt, to name a few, and those are typically deficient in western Canadian feeds.
Providing bulls with blue salt over the winter is not sufficient, and without trace minerals, semen quality may be insufficient for conception.
Attention must also be paid to vitamins A, D and E, Yaremcio added. Vitamin E is particularly important because it is often deficient in commercial mineral programs.
He also advised caution when buying an older bull at auction or from someone else’s herd. Though this can save money, it comes with risk.
“You have to know the health history of the previous herd so that you’re not bringing in something that’s going to create troubles for you in the long run.”
Buyers should ask for health records on the bull and inquire about herd health issues in the bull’s former herd in the recent past.
The National Animal Disease Information Service notes on its website that bull purchase is a common way for disease to enter a farm.
“Too many farms think they are closed but buy bulls. A bull is as likely to be infected with an important disease as a cow and, because of the close contact during mating, far more likely to spread it,” NADIS reports.