CHANGES IN BLOOD COAGULATION PROFILES OF DAIRY COWS DURING PREGNANCY AND IN HEIFER CALVES AFTER HORMONE TREATMENT

Abstract

Blood coagulation profiles were determined throughout pregnancy in dairy cows. Unlike the pregnant human female or the pregnant bitch, the bovine coagulation profiles remained relatively constant throughout pregnancy and showed little change in response to the changes in plasma levels of estrogen and progesterone which occur during pregnancy. While there was a tendency for the platelet count to decrease and the plasma fibrinogen levels to increase during pregnancy, the levels of specific coagulation Factors VIII and XI remained constant and Factors VII and IX showed an increase in some animals but not in others. The changes in coagulation profiles of heifer calves after treatment with progesterone and estrogen alone and in combination were similar to those observed during pregnancy.