Embryo transfer as a method to eliminate pathogenic agents in a rabbit colony

To regain the SPF status of a contaminated but genetically valuable rabbit breeding unit, embryos from the contaminated does were transferred into SPF recipient females. Embryos were collected on day 3 of gestation by flushing uterine horns. All usable embryos were frozen, part of them were not transferred and kept in liquid nitrogen forming a stock of highly valuable genotypes.
Thirty-two stimulated does produced 893 embryos, among which 821 (92%) had an intact zona pellucida and were cryopreserved. From this stock, 478 embryos were thawed, 466 were recovered (97.5%) and 417 were of good quality (87.2%). In 30 does, 10 to 18 embryos were surgically transferred per recipient doe and 24.9% (104/417) of them developed to term after transfer. This corresponds to an average number of 3.47 (104/30) live newborns per recipient.
Health screenings performed on sanitized rabbits confirmed the disappearance of pathogenic agents.