3 YEAR RESULTS OF IN-VITRO PRODUCTION OF BOVINE EMBRYOS IN SERUM-POORBOVINE OVIDUCT CONDITIONED MEDIUM - AN OVERVIEW

This paper presents a synthesis of 3 year results of in vitro producti on of bovine embryos in medium previously conditioned by bovine oviduc t epithelial cells. In Louvain-la-Neuve, Belgium, a total of 18 356 oo cytes were matured and inseminated in vitro: 13 967 (76%) had cleaved at 3 days postinsemination and 3 593 (26%) became blastocysts using th is culture system. Our data show that conditioned medium can be stored frozen for up to 3 years without significant loss of activity and is resistant to lyophilization. One single batch of conditioned medium wa s tested within the same period in four different laboratories and yie lded variable results: 27 and 37% blastocysts/cleaved embryos in two o f them and only 7 and 0% in the two others whereas in each case more t han 30% blastocysts were obtained with the local reference co-culture system. In one laboratory, the batch of oil used to overlay the cultur e drops had a detrimental effect on the blastocyst rate in conditioned medium but not in coculture.