He’s big and stout with just a touch of snort to him - the picture of virility and exactly the kind of bull you need for your cowherd.

With a calf crop on the line, though, it’s no time to judge a book by its cover, according to Twig Marston.

Speaking to area beef producers at Fredonia, Kan., recently, the Kansas State University beef cattle specialist stressed that the dollars and cents of the matter are far too important to take bull fertility for granted.

“We need to do a few things to get ready to go to the breeding pasture,” Marston told cattlemen gathered at Fredonia Livestock Auction. “If you just kick a bull out with a bunch of cows - especially if he’s a yearling - you may be asking for trouble.”

Marston discussed year-round bull management but he began with the importance of thoroughly checking out a bull before he heads to the pasture.

A physical examination focusing on the bull’s physical ability to breed cows and hold up during the breeding season is a critical first step. Eyes, hocks, feet - all need to be right or fertility won’t matter.

Scrotal size is another essential consideration.

“Scrotal size is really pretty important,” Marston said. “It tells us about the bull’s development, it’s an excellent indicator of sperm production and it has an effect on when that bull’s daughters reach puberty.”

A 12-14 month old bull should have a scrotal circumference of about 34 centimeters- that’s about the size of two Pepsi cans side by side, Marston explained.

If your bull is more of a two V8 cans kind of bull - around 29 centimeters - you’ll very likely be giving up fertility.

While bulls with larger scrotal circumference likely have the ability to handle more cows, Marston said a general rule regarding 14- to 20-month-old bulls is that they can handle one cow for every month of age.

Semen quality should also be checked but Marston cautioned that adequate semen quality alone won’t guarantee the bull is going to settle cows. He also warned producers not to test semen quality too far in advance of turn-out.

Spermatogenesis, the production of sperm, takes about 63 days and consists of several cycles. A bull tested 100 days out could suffer some type of physical insult and be sterile at turn-out even though he had adequate sperm quality just a few months prior.

Testing 30-45 days before use is the beef specialist’s recommendation.

Body condition is another important consideration.