Abstract The majority of freemartins are infertile and its karyotyping is XX/XY sex chromosome chimaerism. We have developed a new diagnostic method based on the detection of Y-chromosome DNA segments (Sry) by polymerase chain reaction (PCR) to detect infertile freemartins in cattle. In comparison with other diagnostic aids including clinical observations, erythrocyte typing, and homograft tolerance, this PCR method is more efficient, less expensive, and more practical for routine early diagnosis of the bovine freemartins.
