Viability of one-cell bovine embryos cultured in synthetic oviduct fluid medium

Abstract

Synthetic oviduct fluid medium supplemented with human serum (SOFM-HS) was evaluated as a culture system for maintaining the viability and in vitro development of one-cell bovine embryos. When one-cell embryos were collected surgically and cultured in SOFM-HS, 64% ( 39 61 ) and 76% ( 31 41 ) developed to blastocysts in separate experiments. On transfer (three embryos per recipient), 62% of cultured blastocysts developed as embryos, a pregnancy rate similar to that obtained following direct transfer of Day-7 blastocysts (67%, estrus = Day-0) or Day-2 one-cell embryos (63%). Fewer blastocysts developed in culture from one-cell embryos collected post mortem, with only 24 and 54% forming blastocysts after 120 and 144 h culture, respectively, compared with 61 and 76% of the embryos derived surgically. Following transfer, pregnancy rates were similar at Day 23 for blastocysts from either source, but was less for post mortem-derived embryos at Day 70. The results indicate that SOFM-HS can be utilized as a suitable culture medium for one-cell bovine embryos. A loss of viability in post mortem-derived embryos between Days 23 and 70 of pregnancy was observed.