Why to Ultrasound Over Blood Test for Preg Checking

When it’s time to preg check your cows, the tools you choose matter — not just for knowing who’s bred, but for making better management decisions across the board.

Blood testing might seem easy, but here’s the truth: You’re waiting for the results (minutes to days)… and those results can still mislead you. Studies show that residual pregnancy-associated glycoproteins (PAGs) can trigger false positives weeks or even months after a cow has lost a pregnancy.

That’s time lost. And time, in the cattle business, is money, especially right now.

Ultrasound Tells You More — Right Away Ultrasound doesn’t just tell you “yes” or “no.” It gives you real-time, chute-side information that can reshape how you manage your herd:

✅ Pregnancy confirmation — accurate and instant

✅ Fetal aging — know how far along she is

✅ Sexing — heifer or bull, plan your genetics and marketing

✅ Viability — is the calf alive?

✅ Twins & abnormalities — critical info for culling or calving prep

With ultrasound, there’s no waiting, no mailing samples, no guessing. You get the data in the moment, while the cow is still in the chute — and you can sort on it immediately.

Better Information = Better Decisions

Whether you’re sorting opens, making culling decisions, or selecting replacement heifers, ultrasound arms you with better intel.

Many producers tell us that once they’ve seen the power of real-time ultrasound, they never go back

Ready to Make the Switch?

We’ll help you get started with hands-on training, easy-to-use portable equipment, and support every step of the way.

👉 Call today for more info!

👉Call your local vet to schedule your herd’s pregchecks now.

See more. Know more. Right now.

Interested in Learning More? Check out these sources below…

1. Northrop et al. (2019) – PLOS ONE Goal: Compare two PAG-based blood tests to ultrasound in beef cattle.

   • Goal: Compare two PAG-based blood tests to ultrasound in beef cattle.
   • Findings:
     • Blood tests aligned well with ultrasound for initial pregnancy detection.
     • BUT: Most cows that later lost pregnancies still tested positive due to lingering PAGs.
   • Takeaway: Blood tests may miss early embryonic loss — ultrasound detects it.

2. Ergene et al. (2018) – Kafkas Univ. Vet Journal

   • Goal: Compare PAG & PSPB blood/milk tests to ultrasound in dairy cows.
   • Findings:
     • High accuracy across all methods at 28–30 days post-insemination.
     • False positives occurred in some embryonic deaths.
   • Takeaway: Blood/milk tests are reliable — but ultrasound offers real-time confirmation.

3. LSU AgCenter (2023)

   • Overview: Practical guide to pregnancy detection methods.
   • Highlights:
     • Blood tests detect PAGs and work as early as 25–29 days.
     • But PAGs can remain after calving → false positives.
     • Ultrasound gives instant results + confirms heartbeat, fetal sex, and twin pregnancies.

Method Comparisin at a Glance