THE PREPARATORY PHASE OF DELIVERY IN CATT LE, UNDER CONSIDERATION OF THE EXTERNAL SIGNS OF DELIVERY AND CHANGES IN PROGESTERONE TO PREDICTING THE CALVING TIME

To evaluate changes in the externally recognizable indications of part urition, the body temperature and progesterone profile examined in 9 H olstein-Friesian heifers and 14 Holstein-Friesian cows in the preparat ory phase of parturition. A special external obstetric examination was performed on these animals in the last 263 hours of pregnancy. Furthe rmore, the vaginal and rectal temperature was measured, and blood samp les were taken. Of the blood samples the plasma progesterone concentra tion was determined. The time of birth could be predicted to be in the next 22 hours on the basis of the relaxation of the broad pelvic liga ments in 52.5 % of the cases. A prediction was possible in 43.5 % of t he cases on the basis of the drop in temperature, and in 91.3 % of the animals using the reduction in progesterone levels. Considering the c linical signs of parturition ''relaxation of the pelvic ligaments'' an d a decrease in temperature'', predicting the time of parturition was possible in 65.2 % of the animals. In 8.7 % of the cases, in which no reduction in the progesterone level below 1,5 ng/ml blood plasma could be seen, the time of delivery could be determined by considering the relaxation of the broad ligaments and the reduction in temperature. A prediction of the time of parturition to be in the next 22 hours was p ossible for all animals the indicators of parturition.