Values of three coagulation screening tests of precolostral calves.

Prothrombin times, partial thromboplastin times and platelet counts were performed to determine normal values and to screen for coagulation defects of precolostral calves. The precolostral calves were in two groups: one group of a few calves was tested two years before the second larger group. The results for both groups were similar. The tests were performed on postcolostral calves and on mature cows to compare their values with those of precolostral calves. The mean values of prothrombin times and partial thromboplastin times of precolostral calves in the first group were 18.8 seconds and 54.8 seconds respectively. The mean values of prothrombin times and partial thromboplastin times of precolostral calves in the second group were 18.8 seconds and 50.8 seconds respectively. The mean platelet count was 422,400/cmm for the first group and 482,800/cmm for the second group.