COMPARISON OF 6-DAY BOVINE EMBRYO DEVELOPMENT IN UTERINE TUBE (OVIDUCT) EPITHELIAL-CELL COCULTURE VERSUS INVIVO DEVELOPMENT IN THE COW

A study was designed to evaluate and compare the appearance of embryos recovered from donor cows on Day 6 to embryos from in vivo fertilized cow zygotes developed to Day 6 on uterine tube (oviduct) epithelial cell co-culture using serum-free CZB medium. Embryo stage of development and quality score were assessed. Hoechst 33342 DNA stain was then used to determine the total number of blastomeres, the number of poor nuclei and the number of nuclei in mitosis. Mean cell counts did not differ for the 70 embryos evaluated in each group (65 cells in vivo, 61 cells in vitro). The percentage of transferable emryos (excellent, good or fair quality), in each group also did not differ (57% in vivo, 56% in vitro). There were no significant differences in any of the measured parameters. Our findings suggest that co-culture of in vivo produced cow zygotes can result in embryos comparable in developmental stage and quality to embryos developed in vivo in the cow for 6 d. © 1990.