A new article on a novel method of pregnancy diagnosis in cattle by researchers at Iowa State University and Virginia Herd Management Service has been published in the prestigious The Veterinary Journal. This article describes the use of dried blood spot technology for diagnosis of pregnancy from 28 days post-mating, samples being collected via the TEGO Blood Collection Kit.
Traditionally pregnancy diagnosis has been performed via rectal palpation or ultrasound. More recently it has been found that pregnancy can be detected from 28 days using pregnancy-associated glycoproteins (PAGs) in blood. This method of pregnancy diagnosis is being increasingly adopted as advantages under certain management conditions are being recognized. Blood testing can be more economical than traditional testing in smaller set-ups with fewer cows to be tested, or in remote areas where pregnancy testing is not currently carried out due to travel time from the local veterinary practice. Blood testing can also be useful to maximize the efficiency of artificial breeding programs where pregnancy status needs to be known in between vet visits in order to know which animals are empty and need to be treated to induce the next estrus cycle. As with palpation or ultrasound diagnosis, the veterinarian should be consulted when doing blood testing as test results are part of effective fertility and herd health management.
While these advantages of blood testing exist, there are some challenges to collecting blood in tubes. A skilled operator is required to draw the blood sample from the vein. Blood tubes are transported cooled and need to be protected against breakage, adding to shipping costs. The TEGO device overcomes these limitations. Applied with Allflex ear tag applicators the device quickly and simply creates a bleed on the ear and absorbs the blood onto the self-contained blood card. The cards are then placed in envelopes and returned to the lab at room temperature. An alternative product - TEGO Card can also be used to collect dried blood spot samples. In this case the producer creates a bleed on the ear with a lancet or needle and simply holds the card to the ear to collect the sample.
The authors developed a laboratory process for processing the dried blood spot samples for pregnancy testing. This dried blood spot laboratory process yielded equivalent results to blood tubes for both pregnant and empty cows in a total of 68 cows of known pregnancy status, with no false positive or false negative results. The study concluded that dried blood spots can be used as an alternative for pregnancy diagnosis with the benefits of easy blood collection, shipping cost savings and convenient sample storage.
The abstract of the article is available online.
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