Pregnancies following 24‐hour co‐culture of equine embryos on foetal bovine uterine monolayer cells

Abstract

Summary A total of 77 embryo collection attempts from 28 donor mares resulted in 50 embryos (64.9 per cent recovery rate) ranging from Day‐6 morulae to Day‐7 expanded blastocysts. Thirty‐five of these embryos, classified as quality grades 1 and 2, were allotted randomly by developmental stage (Stage‐I, precapsulate and Stage‐II, postcapsulate) to a control group transferred non‐surgically within 1 h to synchronised recipients, and a treated group, cultured on a monolayer of foetal uterine fibroblast cells for 24 h prior to non‐surgical transfer to recipient mares. There was no significant difference in pregnancy rates between Stage‐I and Stage‐II embryos, nor between the control group (53.3 per cent) and the 24 h co‐cultured group (42.1 per cent). The use of a co‐culture system may provide a viable alternative to cryopreservation for the transport of equine embryos from one station to another.