As calving season ramps up across the country, it’s time to start planning ahead for spring breeding.
“Right now we’re at the prime time to make sure our bulls are able to perform at their best and get the job done,” Kansas State University Beef Veterinarian Dr. Larry Hollis says in an interview with K-State Radio Network and Agriculture Today.
According to Hollis, there are several key steps to making sure your bulls are in “fighting shape” before being sent to work.
First up is nutrition.
“These bulls have had a hard time getting through winter,” Hollis says. “They won’t perform in their peak unless they are in the proper body condition, and we can do some things about that now.”
Hollis says an optimum body condition score on a scale from one to nine is a six. Too fleshy and they’ll have trouble breeding. Too thin and they’ll spend all their time searching for food instead of servicing cows.
“For bulls, this is an athletic event,” he says. “We really have to take them into the breeding season in the shape we want them in.”
Hollis also reminds producers to evaluate their feeding programs to make sure bulls are receiving proper supplementation of vitamins and minerals – particularly vitamin A. According to him, vitamin A is crucial to spermatogenesis, the building of sperm cells.
This makes it essential for producers to have their bulls in good condition and vaccinated within 61 days of turn out, since that is how long it takes sperm cells to build from start to finish.
“We need to be thinking ahead to when we’re going to vaccinate, and keep them in line with the rest of our herd,” Hollis says, suggesting producers look at diseases that will not only affect the bull, but the cows’ reproductive status. These include Infectious Bovine Rhinotracheitis, Bovine Viral Diarrhea and Blackleg.
“Every year we see Blackleg death losses because somebody failed to booster for a year or two,” he says.
Bulls also need to be put through a breeding soundness evaluation.
“We’re going to look at feet and legs because that’s crucial for him to be able to cover the country and cover the cow,” Hollis says. “We also want to make sure both his eyes are clear.”
While bulls primarily use scent for close proximity activity, Hollis says they rely heavily on their eyes for things that happen in the distance. This can include cows in heat being ridden by others.
The evaluation also includes an external exam of any reproductive organs that can be palpated from the outside. Hollis says this year bulls need to have their scrotums checked for frostbite after much of the country received long spells of dipping temperatures.
“On young bulls we want to measure the scrotum to make sure it’s adequate for the age of that bull,” Hollis says. “There’s a direct correlation between his scrotal circumference at a young age and the early maturing and fertility of any replacement heifers we might keep that were his offspring.”
Veterinarians will also check the internal sex glands for infection or anything else that could cause infertility. At this point bulls are then semen tested. Samples are evaluated to look for the presence of white cells, which indicate infection, blood, or any other abnormal cells that could lead to a bull’s inability to service cows.
“If there’s a reason, we want to fail that bull,” Hollis says. “Or at least have them come back in for a retest to see if they’ve cleared up the problem. The thing we don’t ever want to do is turn out a bull we don’t think can get the job done.”
Lastly, Hollis strongly urges producers to have non-virgin bulls tested for Trichomoniasis, even if they were on the producers place during the prior breeding season. Since cases of trich have increased, he says it’s not worth the risk.
“Unless you know exactly where that bull has spent every day of his life since breeding season, I would trich test experienced bulls,” Hollis concludes. “We have had situations in the past where that has saved us a wreck because we caught it when putting it on the tail end of the evaluation.”