Diagnosis of pregnancy in the thoroughbred mares by the rabbit ovulation test (report of experiments carried out during four breeding seasons — 1945-46 to 1948-49)

Abstract

Experiments with the rabbit ovulation test, for the diagnosis of pregnancy in the thoroughbred mares, were carried out during four breeding seasons (1945-46 to 1948-49). The method used in this work includes some modifications indicated by the authors’ experimental results. During this investigation, a total of 233 tests were applied to blood specimens collected from 77 individual mares at different stages of the gestation period. One hundred and eighty-five results were obtained. From these, 127 had been given as positive and 58 as negative. Fifteen out of 127 positive reacting mares did not foal, and from the 58 negative reactors one foaled subsequently. From the 127 positive results, 44.09 per cent were obtained before the 49th day aftev breeding and 55.90 per cent were obtained between the 49th. and 84th day after last service. Only three mares were bled after the 84th day. If the 15 false positive results are not interpreted as a failure of the test, an accuracy of 99.45 per cent will be reported, but in the contrary case, the test will be proved correct in 91.35 per cent. In one instance, the blood samples gave positive results when they were
collected at the 8 th and 25th day after the abortion, being negative when they were retested at the 43th day.