Posted: May 6, 2016

A new blood test can save dairy farmers time and money by indicating whether or not their cows are carrying embryos.

Troy Ott
Troy Ott, professor of reproductive physiology, takes a sample of blood from a cow.

A couple dollars a day doesn't seem like much, but multiply it by 100 or more, and it becomes cause for alarm. A new simple-to-use blood test that determines whether a cow has failed to conceive after insemination has the potential to save dairy farmers, who in the United States manage an average of a little over a hundred cows, $1 to $3 per day per animal.

Already patented in the United States and nine other countries, the test--being developed by Troy Ott, professor of reproductive physiology--detects a protein that indicates if a cow is carrying an embryo. The information can be available to farmers 18 to 20 days after the animal has been inseminated, which is 10 to 20 days earlier than current methods.

Called the "Open Cow Test" because it indicates when a cow is "open," or not pregnant, the new test involves taking a small blood sample from the tail vein. The sample can then be sent to a lab or tested immediately "cow side."

It takes approximately three inseminations for the average cow to achieve a pregnancy. The average interval between inseminations is dictated by how soon a pregnancy can be detected and is about 40-50 days. Ott's test is aimed at cutting that in half.

"The test will be a tool that a dairy producer can use to manage fertility and help cows calve on a 13-month schedule and avoid early culling," says Ott.

Early pregnancy tests, like those available for humans in most drugstores, have eluded the dairy industry.

The traditional test used to detect most cow pregnancies--called "transrectal palpation"--is neither easy nor pleasant for dairy farmers and veterinarians. Donning a long glove, they reach shoulder deep inside the cow's rectum to feel for an embryo inside the uterus.

The test is accurate after 35 days and has many downsides beyond the timing, including shoulder problems for the farmer, noted Ott. There is a blood pregnancy test on the market that is accurate and affordable after 28 days, he says. The test Ott is working on is the only one that would allow detection of pregnancy status aligned with the 21-day cycle of the cow.

According to Ott, cows must calve every year to produce enough milk to be profitable. To maintain the yearly calving interval, cows need to conceive around four months into their lactation. The longer a cow is not pregnant, the more it costs dairy farmers because they are feeding her more and she is producing less milk each day. In the United States, failure to conceive is the primary cause for early culling of dairy cows to be sold for meat. As a result, the sooner a farmer can tell if a cow has been successfully inseminated, the better it is for the cow and the farmer.

Ott is working to bring his test to market with the help of a $75,000 Research Applications for Innovation, or RAIN, grant from the College of Agricultural Sciences Entrepreneurship and Innovation Program. The Penn State Research Foundation contributed $25,000 to the award, which is designed to help researchers commercialize their discoveries.

--Martha Schupp