Structural soundness plays a large role in whether a bull will be able to get cows bred, so Lemenager suggested inspecting feet and leg structure, eyes and muscle shape, a factor that contributes to calving ease.

Also important is genetic merit. Genetic defects have the potential to cause problems in the herd.

"Almost every breed has one or more genetic defect, and they can sneak up on you if you're not careful," Lemenager said. "Producers need to study the pedigrees and know which bulls are free of genetic defects, or buy bulls that have been DNA tested and declared free of known defects."

Producers also need to study up on a bull's expected progeny differences, or EPDs. Calving ease, maternal calving ease, growth traits, maternal milk and carcass traits can all affect a producer's bottom line.

"We really need to keep an eye on the EPDs for the economically important traits," Lemenager said. "We need to stay away from single trait selection and emphasize multi-trait selection to make herd improvement that complements marketing strategy. If you're saving back replacement heifers, things like maternal calving ease and maternal milk become very important. Growth traits such as weaning and yearling weight affect the pounds available for sale. Carcass traits, such as marbling, backfat and the ribeye area are the main drivers for how these cattle hang on the rail. 

"I'd also do an independent cull on frame size, so the cattle don't get to be too big or too little."

It's not until all of these traits have been met that Lemenager recommends producers start looking at the animal's phenotype, or "look."

Much of this same advice applies to producers who manage an artificial insemination breeding program. And while commercial AI studs tend to do a good job of screening animal health, AI sires can still perform differently.

"Some bulls produce semen that's of higher quality or that gets cows bred better than other bulls," Lemenager said. "So, here again, producers need to do their homework before they start spending a lot of money on semen. They need to know that the bull has been working, that cows have been conceiving to that semen and that the offspring are performing as expected."