For cow-calf producers, pregnancy diagnosis is one of the most important management checkpoints of the year. Identifying open cows can have a major impact on input costs and marketing decisions.

Producers today have three primary options for pregnancy diagnosis: rectal palpation, ultrasound, and blood-based tests. According to Aaron Berger, University of Nebraska Extension beef systems educator, and Dr. Thiago Martins, University of Missouri Extension beef reproduction specialist, the best method depends on timing, facilities, labor availability, and how much information you want to receive from the test.

“There are multiple ways to determine pregnancy in beef cows,” Berger said. “Rectal palpation, ultrasound and blood tests all have a fit. The key is understanding what information you want and when you need it.”

Rectal Palpation

Rectal palpation remains the industry standard for commercial cow-calf producers — and for good reason. “It’s been used for decades,” Berger said. “It’s relatively quick, and in the hands of a skilled technician, it’s very accurate.” He recommends waiting at least 45 days post-breeding to reduce the risk of misdiagnosing the cow as open. For most operations, checking cows 45 to 60 days after bulls are removed from the herd provides reliable results and allows producers to sort open cows in time to make good marketing decisions.

“That’s really the economic driver,” Berger said. “Identifying open cows before you invest feed resources into them is critical.”

Rectal palpation allows producers to quickly determine pregnancy status and, in many cases, estimate gestational age. That can help evaluate breeding distribution, which is especially important in herds aiming for a tight calving window.

Martins emphasized that training and experience are key. “Rectal palpation is a very good method, but it requires training and practice,” he said. “The accuracy depends heavily on the person performing the exam.”

“You can train yourself, but you need proper guidance and a lot of repetition,” he said. “Many producers rely on a veterinarian because they already have the expertise and can do it efficiently.”

Ultrasound

Ultrasound offers everything rectal palpation does — plus more detailed information. That extra insight can be valuable when evaluating breeding performance or tightening the calving season.

“With ultrasound, we can detect pregnancy earlier than palpation and determine fetal age more precisely,” Martins said. “In some cases, you can even determine fetal sex if you’re in the right window.”

Pregnancy can often be detected via ultrasound as early as 28 to 30 days after breeding. For producers using AI or synchronization protocols, early ultrasound can provide timely feedback on conception rates. “The earlier you know, the sooner you can make decisions,” Berger said. “If you’re trying to evaluate AI success or shorten your calving window, ultrasound can give you more detailed information.”

Understanding fetal age can help identify short bred cows that may calve outside the desired timeframe. That information can drive culling decisions or inform management strategies for the following breeding season. Ultrasound also allows evaluation of ovarian structures, which can help diagnose reproductive issues in open cows.

However, Martins cautioned that ultrasound requires both equipment and skill. “It’s not just about owning the machine,” he said. “You need to know how to interpret what you’re seeing.” In most commercial herds, ultrasound is performed by a veterinarian or a trained technician. “If you’re only preg-checking once a year, it’s hard to justify buying the equipment,” Berger said. “But for larger or seedstock operations that want more detailed data, it may make sense.”

Blood Tests

Blood-based pregnancy tests have gained popularity in operations where scheduling or facilities make traditional preg-checking more challenging. “One of the advantages of blood tests is flexibility,” Berger said. “You can collect samples during routine processing and ship them to a lab.”

Blood tests detect pregnancy-associated proteins and can identify pregnancy as early as 28 to 30 days post-breeding. But timing still matters. “You need to make sure you’re far enough from breeding for the test to be accurate,” Martins said. “And if a cow recently lost a pregnancy, those pregnancy proteins may still be present for a period of time.”

Unlike palpation or ultrasound, blood tests do not provide immediate results. Producers must wait for the lab results before identifying if the cow is bred or open.“You’re not getting an instant answer,” Berger said. “There’s a delay between collecting the sample and receiving results.”

If skilled technicians aren’t available to do a rectal exam or ultrasound, drawing blood samples may fit easily into the workflow. “It doesn’t require as much specialized training to collect blood as it does to perform palpation or ultrasound,” Martins said. “But you still need good handling facilities and proper sample management.”

“There isn’t one method that’s best for every operation,” Martins said. “It depends on herd size, budget, facilities and how much information you want.”

Both he and Berger stressed that consistency matters more than the specific tool used.

“What’s most important is that you’re evaluating reproductive performance every year,” Berger said. “Pregnancy diagnosis is one of the most powerful management tools we have.”

Train Yourself or Hire an Expert?

Once producers have identified which method to use, they may ask the question ‘Should I learn to do it myself?’. The short answer is “it depends.”

“You can absolutely learn these techniques,” Martins said. “But it requires commitment and proper training.”

Berger encourages producers to consider labor availability and opportunity cost. “If hiring a veterinarian ensures accuracy and allows you to focus on other priorities, that may be the best decision,” he said. He also emphasized the importance of a relationship with your local veterinarian, as they can be a tool in your management toolbox.

Larger operations that preg-check frequently may benefit from developing in-house expertise. Smaller herds often find that hiring a veterinarian once a year is both practical and economical. Regardless of method, the ultimate goal is to have clarity around each animal’s reproductive performance.

“The method you choose should support your management goals,” Berger said. “What matters most is using that information to improve herd profitability.”

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