Blood samples, like the one being pulled here, offer a means to find open cows sooner and more objectively than some other methods. These samples must be analyzed by a laboratory.

Rather than fight the summer heat and humidity in Gilmer, Texas, Wilburn Tefteller, Jr., has adapted his dairy’s breeding program to it. He no longer tries to breed cows in June, July or August; instead, he seasonally breeds his Soules Chapel Dairy herd in late fall or early spring.

That means he must get about 275 cows bred and confirmed pregnant within a short time frame.

To help him accomplish this goal, he uses a blood-pregnancy test called BioPRYN. The test uses an enzyme-linked immunosorbent assay to evaluate samples for the presence of pregnancy-specific protein B (PSPB) produced by certain cells in the placenta. (Other pregnancy tests on the market evaluate blood or milk samples for the presence of progesterone or other hormones and proteins.)

To learn how to use blood-pregnancy-test results as part of your breeding program, follow these steps. The following information is geared toward a test that is taken 30 days after insemination and evaluates for PSPB.

1. Identify animals for testing.

Use herd-management software (or by hand if necessary) to assemble a list of cows eligible for testing. Cows should be checked 30 days after insemination. However, current technology requires that cows must be at least 90 days in milk to get accurate results from a blood-pregnancy test. Otherwise, proteins from the previous pregnancy may not have cleared the bloodstream and could interfere with the test.

Tefteller synchronizes cows and then breeds on observed heats. Cows are blood-tested for pregnancy diagnosis on a Monday about 30 days post breeding.

2. Pull blood samples according to manufacturer directions.

Blood samples must be sent to a laboratory for analysis. Ask your veterinarian to pull the samples or else train an employee to do the work.

“Most of our local clients take blood samples on a weekly basis -— not usually when the veterinarian is at the farm, but on another morning when it’s convenient for the dairy,” explains Fred Muller, veterinarian and co-owner of Ag Health Laboratories in Sunnyside, Wash. Doing so allows the dairy to focus the veterinarian’s visit on other areas of need.

For Tefteller, either he or his son pulls the samples.

No matter who pulls the blood samples, make sure he or she receives training on how to process the samples and send them to a laboratory.

Remember that these actions will take time to perform, so be sure to schedule labor and cow activities accordingly.

3. Identify open cows. 

Results are generally available the day after the lab receives your blood samples.

Use the results to key in on open cows, says Matt Lucy, animal science professor at the University of Missouri. “There’s a lot you can do to help a cow that is open at 30 days post-breeding.”

The BioPRYN test has an overall accuracy rate of 97 percent; that is, 99 percent accurate for detecting pregnant animals and 95 percent accurate for detecting open cows. Once identified, open animals can be synchronized or resynchronized for breeding and rebreeding.

When used correctly, these tests are more objective than palpation at 30 days post-insemination, says Lucy.

4. Return open cows to a breeding protocol.

Those using these blood-pregnancy tests say they can gain a week in returning cows to breeding protocols compared to conventional palpation.  

In Tefteller’s herd, cows confirmed open by blood-test results, or have not been inseminated at this point, begin a complete Ovsynch synchronization protocol the following Tuesday.

In an all-A.I. herd, cows identified as pregnant at 30 days post-insemination should be rechecked around day 60 to identify any that may have suffered an early-embryonic loss, recommends Lucy. Cows can be checked by palpation or with another blood test. This allows you to return these now-open cows back to your breeding program as quickly as possible.

In a herd that features both A.I. and bulls, the protocol differs slightly. Cows that lose their A.I. pregnancies early or prove difficult to breed are often put in with a bull.

It is not cost-effective to palpate every pregnant cow at 60 to 80 days to identify the 5 percent or so that may suffer early-embryonic deaths, or the rare false-positive, says Muller. “My clients would tell you that these cows that come back into heat are found by their A.I. technicians quite well, leaving very few undetected open cows to find (by palpation).”

Ultimately, this test, as with any other tool, is as good as those that use it. For Tefteller, the test has helped him shorten the amount of time needed to get all his cows bred by about 30 days. And that is exactly what he was looking for when he gave it a try.

Is this tool for you?

these new early-pregnancy blood tests offer an opportunity to take your breeding program to the next level. But they are not for everyone.

If your herd’s reproduction is a train wreck, this is not the place to start fixing it, advises Matt Lucy, animal science professor at the University of Missouri. “You need to start with clean, healthy cows with good body condition scores, as well as a good herd reproductive program,” he suggests. “Then you can take it to the next level.”

Resource materials

for more information on the biopryn blood-pregnancy test, call BioTracking LLC at (208) 882-9736. Or go to:

This technology continues to evolve. New blood-pregnancy tests are in development from other companies, too. Ask your veterinarian to keep you updated on these analytical tools as they become available.