title: Full-term development of bovine follicular oocytes matured in culture and fertilized in vitro.
abstract: Follicular oocytes were cultured for 28h in vitro and 91% of the oocytes reached the the second metaphase in culture. The penetration rate after insemination in vitro using frozen-thawed spermatozoa was 81%. After cultivation for 48h in vitro, 18% of the in vitro fertilized oocytes developed to the three- to four-cell stages and 21% of these developed to the six- to eight-cell stages. Following in vivo culture in the rabbit oviduct, 18% of six- to eight-cell and 5% of three- to four-cell embryos developed to the blastocyst stage. To confirm the full developmental competence, 11 blastocysts were transferred to recipient cows, and six (55%) cows became pregnant or delivered calves.
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture Kyoto University, Kyoto 606, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Utsumi
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: A
authors.initials: A
authors.lastname: Iritani