Blood Pregnancy Tests Keep Repro Humming at this Iowa Dairy
Reproduction clicks along like a well-oiled machine at Schanbacher Acres near Atkins, Iowa, thanks in part to the farm’s routine use of blood pregnancy tests for the past 17 years.
“We’re located 90 minutes away from our veterinarian,” said Carissa Buttjer, assistant herdsperson for the 280-cow Holstein herd. “The ability to do our own pregnancy testing – at an earlier stage and on a more regular basis than palpating – really helps us keep our pregnancy intervals tight.”
Schanbacher Acres uses tests and diagnostic services supplied by Idaho-based BioTracking LLC. The company’s blood pregnancy test, bioPRYN, diagnoses pregnancy by detecting significant levels of a pregnancy-specific protein in the blood of pregnant ruminants.
The test can deliver accurate results from blood samples drawn as early as 28 days post-insemination. At Schanbacher Acres, they draw blood at 30 days post-breeding for cows and 45 days for virgin heifers. Cows confirmed pregnant receive a second, confirmatory test at 60 days to identify any that have experienced early embryonic death.
“Heifers don’t lose pregnancies very often, so they don’t need a second test,” shared Buttjer. “That’s very convenient, because we’re not handling them every day like we are the lactating cows.”
Every Tuesday is “repro day” on the farm, and a computer-generated list signals to Buttjer which cows need blood samples drawn. The necessary supplies are minimal, consisting of 3-mL vacuum tubes and blood-draw needles.
“The needles are technically called ‘multi-sample’ blood-draw needles, but I switch needles between every animal,” said Buttjer. She orders both the vials and needles from veterinary supply company Leedstone. The only other essential tool is a Sharpie® marker for labeling vials.
Buttjer draws around 15 samples a week, which are boxed up and shipped out to a lab in Washington state the same day. The vials must be carefully packaged for shipping via the U.S. Postal Service, but do not require cooling or refrigeration. Results typically arrive in her e-mail inbox by Friday of the same week.
The cost of each test is $2.50. When equipment and shipping costs are added, the total expense per sample is about $3.22.
There are a few drawbacks to the technology, including the fact that feedback is at the mercy of shipping efficiency. “When the Post Office gets busy, especially at Christmastime, it sometimes can take 2-3 weeks to get our results,” shared Buttjer. Other limitations include the fact that fetuses cannot be aged or sexed, and twins are not detected.
Perfecting the technique of drawing the blood samples was a bit of a learning curve for Buttjer, but the process – which she demonstrated on a recent Iowa State University webinar – now is routine for her.
On the webinar, she also explained the herd’s use of basic activity monitoring collars for heat detection. Cows that do not show natural heat shortly after the herd’s voluntary waiting period of 70 days post-freshening are enrolled in a timed-A.I. protocol.
The combination of systematic breeding procedures and quick, early pregnancy information has helped Schanbacher Acres achieve a highly efficient average calving interval of 13.0 months. The trickle-down benefits compound as a result: more calves born per year; higher fresh-cow frequency that boosts milk production; more consistent body condition; and greater lifetime performance per cow.
“I think the simplicity of this technology is one of the reasons it works so well for us,” stated Buttjer. “It’s just a very easy-to-use and reliable tool, and I really wouldn’t want to be managing breeding without it.”