Growing Beef Newsletter
August 2026, Volume 17, Issue 2
Herd Bull(s) Assessment
Patrick Wall, ISU Extension beef specialist
I hope this article finds you in conditioned air, staying hydrated and out of the sun. Less the A/C, I hope your cow herd is able to do the same. Excessive summer heat stress was definitely not what the U.S. cow herd needed to endure given our inventory, and summer is far from over. This article will focus on the other half of the genetic pool: herd bulls.
Depending on when you calve, your current bull battery is either standing in the bull pen off cows, or still in the trenches of breeding season. In parts of Iowa, April-May calvers have certainly faced some heat stress challenges during re-breed. Regardless of your desired calving window for 2027, here are some helpful management tips in the near-term.
- Assess herd bull(s) body condition. Keep in mind, there are two ways a bull gets "skinny" while covering cows. A.) He didn’t convert the forage you offered him very well. OR B.) He worked his heart out covering most of the herd. The same assessment can be said in the other direction evaluating a bull that maintained body condition. A.) He didn’t breed a dang thing. OR B.) He’s the unicorn you have been looking for that can stay in good flesh while covering cows. A DNA parentage test of the calves is the only way to really assess either bull’s value. Bottom line don’t cull the skinny bull; he might be the one doing all the work.
- Make sure they bounce back. Bulls are expensive and feed is relatively cheap. Offer some grain and/or high-quality forage to help bulls regain weight, especially yearlings. Remember that yearling bulls are still growing and maturing, so ample protein and energy is critical to their development.
- Pregnancy check promptly. Ultrasound technology can accurately detect pregnancy as early as 28 to 30 days. Given the summer heat, cows might not be showing visible signs of estrus -- or they might not be cycling at all. The faster you know your potential open rate, the quicker you can respond.
- Feet and legs. This might sound trivial if you’re looking at the bull(s) every day, but are you really looking? How do their feet look on a close inspection? Was their toe wear symmetrical? Are there any vertical or horizontal cracks? A crack up high may show up as lameness later as the claw grows and wears. Is there any swelling or inflammation in the pasterns, hocks, or knees? Bull injuries are common; they’re even more common if bulls are commingled after coming off cows.
It’s never too early to start thinking about the next breeding season. Once you have thoroughly assessed your current bull battery, what’s missing? If you retain heifers, was calving ease sufficient? Moreover, do you need to address or enhance mature size of the females you do retain? If you retain ownership, are you happy with gains, carcass weights, feed conversion, grid premiums, etc.? All of these traits can be addressed through your next bull purchase. Other questions: Does your calving window make sense with your labor resources and marketing plan? Is cow longevity or re-breeding rate a problem? Could you capture more heterosis by considering a new bull breed? Thinking about all of these things now could better prepare you for what will be coming soon: bull sale season.
This monthly newsletter is free and provides timely information on topics that matter most to Iowa beef producers. You’re welcome to use information and articles from the newsletter - simply credit Iowa Beef Center.
