PREGNANCY-ASSOCIATED GLYCOPROTEIN CONCENTRATIONS IN NON-PREGNANT COWS: A CASE STUDY

The aim of the present work was undertaken to describe three cases of the bPAG concentration measure by three RIA systems during the post-partum period in non-pregnantcow. Three Holstein-Friesian cows of mixed age and parity were diagnosed as non-pregnant. Blood samples were removed from the coccygeal vessel into EDTA-coated tubes. Samples were collected every 2 days during a stabling period of two months in the absence of males. Plasma was obtained by centrifugation immediately after collection and was stored at -20 C until assay. Plasmatic PAG concentration was measured by radioim-munoassay technique with some modifications. In RIA-780 and RIA-809, there were high peak of PAG concentration that reached 2.56 ng/ml and 0.89 ng/ml, respectively. These peaks lasted longer than 3 days (two successive samples were positive). The other RIA systems gave the values of PAG concentrations below cut-off of pregnancy diagnosis (> 0.8 ng/ml) and remains always non-pregnant. Our data shows clearly that there is another source of glycoproteins expression (e.g. ovarian) apart from the placenta in cow. The present study could be a field for future larger studies on the same subject by exploring deeply other extra structures placental.