Chromosomal analysis of embryos produced by artificially inseminated superovulated cattle [embryo chromosome, triploid, tetraploid, mixoploid]

To determine the chromosomal complement of pre-morula bovine embryos, 30 Holstein heifers were superovulated and inseminated and their embryos were subjected to chromosome analysis on days 2, 3 or 4. Of the 298 embryos/ova recovered, 101 had one or more cells in metaphase and of these, 60 could be karyotyped. Eight of the karyotyped embryos were chromosomally abnormal, including 3 triploids, 1 tetraploid and 4 mixoploids. It was concluded that the abnormalities occurred at or shortly after the time of fertilization.