Bovine Blood Pregnancy Test Available

What is BioPRYN?
BioPRYN is a blood pregnancy test for ruminants. West Michigan Veterinary Service completes BioPRYN tests for cows, sheep and goats. More specifically BioPRYN is an enzyme-linked immunosorbent assay (ELISA) test to evaluate a specific protein found in a pregnant ruminant's blood.

How it works
The ELISA test evaluates blood samples for the presence of a protein called pregnancy specific protein B (PSPB). The only source of PSPB is in the placenta. This protein can be detected as early as 28 days after insemination.

The test takes less than 24 hours to process once samples are set up in the laboratory, results typically are available the day after delivery to the lab. Testing days at WMVS are Monday through Thursday; Result reporting days are Tuesday through Friday. Samples must be submitted by 1:00 p.m. to be run on that day. Results are typically available at 12:00 p.m. the following day.

When to test
BioPRYN can detect the presence of PSPB in as early as 28 days after insemination in heifers. Similarly, pregnancy can be diagnosed in lactating cows 28 days after breeding but cows also must be at least 73 days in milk to ensure that the PSPB from the previous calf is eliminated from the bloodstream. Sheep and goats need to be 30 days bred for the PSPB to be detected in their bloodstream.


Evaluation of BioPRYN shows that is has an overall accuracy of 99 percent at 28 days bred. Some of the false-positive results are likely due to early embryonic death rather than to test inaccuracy. The false-positive rate has been shown to increase slightly (7-8 percent) in lactating dairy cows during periods of extremely hot weather. The low incidence of false negative results is highly desirable, because cows diagnosed open may be returned to a hormone based breeding program, which could cause them to abort if they are actually pregnant.

To Get Started
Producers can view “Sample Submission” form and “Tube Labeling Instructions and Postal Shipping Procedures” form and submit samples today. For additional information please contact West Michigan Veterinary Service at (616) 837 – 8151, extension 4.

WMVS also has starter kits with needed materials and instructions to start using BioPRYN.