Beef bulls: Getting to, through the breeding season


SALEM, Ohio – The two to three months before your herd bull is turned out is one of the most important times of year in that animal’s life.

He’s working to build or maintain body score and sperm for the breeding season ahead.

His condition today is a good basis to figure what still needs to be done before he’s turned out with the cows.

Overwintered. Most beef bulls have been kept in confinement and will need exercise before the breeding season starts.

Bulls should have a minimum body condition score of 5 going into the breeding season to get ahead of weight they’ll lose covering pastures and cows, according to Stan Smith, a cattleman and Ohio State University extension program assistant in Fairfield County.

Diet. Bulls that have been on grain or other high-energy diets need to be “let down” before the breeding season begins, adds Ohio State animal scientist Stephen Boyles.

This includes gradually reducing their grain ration and easing them onto springtime pastures to prevent digestive problems that can turn into reproductive problems.

“They can probably be put into the pasture field as soon as the grass greens up,” Smith said.

“It’s a good idea to put them out by 30 days before the breeding season starts to get them adjusted to the grass,” he said.

Smith also recommended checking hooves on bulls overwintered inside, where manure might have caused soft hooves or ones that need trimmed.

“If their feet hurt, they won’t get the cows covered.”

Multiple bulls. Smith said there’s a common, but inefficient, thought in herds using multiple bulls: Two bulls will run together, the older teaching the younger the tricks of the trade.

Once the season starts, the thought can create more headaches than it’s worth.

“The mature bulls are more dominant, and a little bull will go through the season and maybe not breed a single cow,” he said.

“And they’re running themselves ragged even if they don’t get to breed any cows,” he said.

Rotation. If cows can’t be separated to run one bull per group, there is still something cattlemen can do. Smith recommends bull rotation.

“That way everyone has a chance to breed and recover. And you know you’ll get some calves out of the youngest bull, which should be your best bull genetically,” he said.

Ratio. During the breeding season, it’s also important for cattlemen to have realistic expectations from their bulls.

A bull shouldn’t be expected to breed too many cows.

See if the bull is mounting cows, and see if any are coming back into heat.

“A good rule of thumb that I’ve heard is one cow per each month of age,” Smith said.

That means a yearling bull can breed roughly 12 cows; a 2-year-old can handle around 24, and so on.

Manage the herd. Smith also said a well-managed herd that calves closely and cycles closely can challenge a bull.

He recommends adjusting the cow-bull ratio to be sure the bull is settling as many cows as possible.

“It really boils down to management. There’s rules of thumb and book sense, but you’ve got to use common sense from herd to herd,” he said.

Deadlines. Boyles said a vaccination and parasite control program, the breeding soundness examination and possible hoof trimming should be conducted at least 30 days prior to the breeding season.

(Reporter Andrea Myers welcomes reader feedback by phone at 1-800-837-3419, ext. 22, or by e-mail at


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