Comparison of ultrasound and pregnancy associated glycoproteins to diagnose and follow ongoing or failing pregnancy in pregnant heifers on the market

peer reviewedThe objective of the present study was to compare transrectal ultrasonography and pregnancy associated glycoprotein (PAG) tests for determination of pregnancy in 72 Holstein-Friesian heifers imported from Holland to Croatia. All heifers came to Croatia with written confirmation of pregnancy. During caranteen we preformed rectal and ultrasound exploration of heifers and simultaneously collected blood samples from each heifer. PAG concentrations were determined by a RIA immunoassay using bovine PAG 67 KDa as a tracer and standard. In our study 68 heifers were confirmed to be pregnant by both methods and 4 cows were confirmed for abortion by PAG test and nonpregnant according to ultrasound checking. Transrectal ultrasonography is accurate test for pregnancy diagnosis in pregnant heifers but it is impossible to say only on basis of ultrasound examination if heifers conceived and aborted or they failed to conceive in the first place. PAG RIA test is not only highly accurate and reliable method to distinguish between pregnant and nonpregnant heifers on the market. It is also useful to determine whether heifers were pregnant and embryo died and was absorbed during the transfer or heifers failed to conceive. It is possible because level of PAG persists in circulation after abortion or embrional death. In doubtful cases it can be used as a proof of pregnancy existence in heifers later confirmed to be nonpregnant