Competency of blood coagulation in the newborn calf.

This study evaluated the haemostatic profiles of a group of 11 female and seven male calves from the day of birth until they were 60 days of age. Similar results were found for both sexes. At birth the plasma activity of the procoagulant proteins, Factors VII, VIII:C, IX, X and XI and fibrinogen were all close to the adult values. Factors VII, VIII:C and fibriogen increased transiently during the first seven days of life but the increases were not sufficient to influence routine coagulation screening assays such as the activated partial thromboplastin time and the prothrombin time. At birth, the plasma concentration of the protease inhibitor, alpha 2-macroglobulin, was approximately 50 per cent of adult values and increased slowly during the first seven days of life; the plasma concentration of antithrombin III was higher than that of alpha 2-macroglobulin. The changes in the plasma concentration of fibronectin paralleled the changes in fibrinogen and Factor VIII:C from birth to 60 days of age; the concentrations of total plasma protein and plasma albumin remained stable and within the adult ranges throughout the 60 days. The plasma concentration of glucose increased transiently during the first 48 hours after birth.