A CESAREAN-SECTION MODEL TO CHARACTERIZE COAGULATION IN THE FETAL ANDUTERINE CIRCULATION DURING LATE-GESTATION IN DAIRY-CATTLE

A study was conducted to measure a coagulation profile including proth rombin time (PT), activated partial thromboplastin time (APTT), thromb in time (TT), fibrinogen concentration (FIB), and plasminogen activity (PLA) in the jugular vein, umbilical vein and artery and uterine vein of 18 Holstein Friesian cows during late gestation. A caesarean secti on was performed on all cows before term in order to obtain blood samp les from the different sources and to deliver the calves. Blood plasma obtained from the umbilical vein and artery had a longer prothrombin time but shorter activated partial thromboplastin time and lower conce ntrations of fibrinogen and plasminogen than peripheral blood plasma. Thrombin time was similar throughout all blood vessels. No significant differences existed between the two samples drawn from the jugular ve in before and during surgery. Highest coefficients of correlation were found between blood samples drawn simultaneously from the jugular and uterine vein (R2 = 41 to 96 %).