EN
The aim of the study was to compare the effect of gonadotropic hormones and granulosa cells on the maturation and developmental capacity of cattle oocytes in vitro, as well as the effect of TCM 199 and DMEM/F12 media on the development of embryos obtained in co-culture with oviduct epithelial cells. Fertilization was performed with the use of frozen semen from 2 bulls. Twenty hours after insemination, presumptive zygotes were placed in co-culture with oviduct cells in a TCM 199 (TCM-KJ co-culture) or a DMEM/F12 medium (DMEM-KJ co-culture) and cultured for 7-9 days. Metaphase II was reached by 40% and 48% of oocytes cultured in the presence of granulosa cells and gonadotropins, respectively. Only embryos obtained from oocytes maturing in the presence of granulosa cells developed to the blastocyst stage. Considerably more dividing embryos were obtained when the presumptive zygotes were co-cultured with TCM-KJ (38.1%) rather than with DMEM-KJ (8.6%; P < 0.01). This study showed that the presence of granulosa cells had no effect on the nuclear maturation of cattle oocytes, but increased their capacity for embryonic development. TCM 199 is much more useful than DMEM/F12 for the co-culture of cattle embryos with oviduct cells.