The on-site bovine pregnancy test for the detection of bovine PAG in serum or whole blood
With the Fassisi BoviPreg it is possible to diagnose a pregnancy approx. 30 days post breeding to identify pregnant and nonpregnant cows.
Early identification of nonpregnant cows and heifers post breeding can improve reproductive efficiency and pregnancy rates by decreasing the intervals between artificial insemination (AI) services and also can increase AI service rates. Thus, new technologies to identify nonpregnant cows and heifers early after an AI play a key role in management strategies to improve reproductive efficiency and profitability on commercial farms.
The pregnancy status should be determined as soon as possible after an insemination. With the support of the Fassisi BoviPreg it is possible to early diagnose
a pregnancy post breeding to identify pregnant and nonpregnant cows to support insemination strategies.
Pregnancy associated glycoprotein (PAG) belongs to a large group of glycoproteins that are synthesised in binuclear trophoblast cells during pregnancy and released into the maternal bloodstream during fusion with uterine epithelial cells (Zoli et al, 1992). According to Green et al over 100 PAG genes are present in the bovine genome, 21 of which have been clearly identified so far (Green et al, 2000). Although PAG function has not been fully explained to date, it has been proven that the detection of PAG in the maternal blood is a highly specific and reliable parameter for diagnosing pregnancy and monitoring gestation. The advantage of PAG compared to progesterone assays lies in the fact that PAG is formed from an intact trophoblast and thus provides direct proof of pregnancy. As soon as an embryo becomes implanted in the womb, this is communicated to the mother’s body via messengers. The latter, which are various pregnancy associated glycoproteins, are produced in the placenta and thus reach the cow’s bloodstream where they can be measured. Pregnancy can be confirmed by means of a PAG-1 (pregnancy-associated glycoproteine-1) assay with 94% accuracy between 30 and 35 days after insemination. This figure can increase to a maximum of 99% after the 40th day. PAG detection is an alternative to standard RIA and can thus be used to diagnose and monitor pregnancy. (Friedrich and Holtz, 2009). A comparison of ELISA results and Fassisi BoviPreg has shown a high level of consistency between the results and a test performance of 96%.
The detection of pregnancy associated glycoproteins (PAGs) represents a revolution in cattle reproduction technology from both a scientific and financial perspective. PAG levels in the maternal blood clearly rise from day 24 to day 28 post-conception. Hence pregnancy can be diagnosed right from the early stages. Glycoproteins were detected just 28 days after insemination in most of the animals examined in this study (between days 30 and 35 in all animals). Gajewski et al (2009) PAG concentrations increase during pregnancy. As shown in the graph, these values rise above the 2 ng/ml limit from the 28th day on average and continue to increase thereafter. It is important to note that PAG concentrations can vary from one animal to the next. The validation study has confirmed that pregnancy can be diagnosed accurately with Fassisi BoviPreg 30 days after insemination. This helps to shorten the calving interval. A check procedure should be carried out after eight weeks to confirm the results as embryonic loss can occur in up to 35 % of animals up to 70 days after insemination.
Friedrich M., Holtz W. (2009): Einsatz eines PAG-ELISA zur Trächtigkeitsüberwachung beim Rind. Dissertation.
Gajewski Z , Pertajitis M, Sousa N, Beckers J, Pawliñski B, Janett F (2009): Pregnancy-associated glycoproteins as a new diagnostic tool in cattle reproduction. Schweiz Arch Tierheilk, Band 151: 577–582.
Green J., Xie S., Quan X.,Bao B., Gan X. , Mathialagan N. , Beckers J.F., Roberts M. (2000): Pregnancy-Associated Bovine and Ovine Glycoproteins Exhibit Spatially and Temporally Distinct Expression Patterns During Pregnancy. Biology of Reproduction 62, 1624–1631.
Zoli P., Guilbault L., Delahaut P., Ortiz W., Beckers J. F. (1992): Radioimmunoassay of a Bovine Pregnancy-Associated Glycoprotein in Serum: Its Application for Pregnancy Diagnosis. Biology of Reproduction 46, 83-92.