Viability and ultrastructure of equine embryos following culture in a static or dynamic system.

The viability and ultrastructure of equine embryos were assessed following culture in a static or perifusion system. The percentage change in diameter was greater (P less than 0.025) for embryos in the static treatment (71%) than in the perifusion treatment (33%). Fluorescein diacetate (FD) scores, the percentage of fluorescing cells (FC) and fluorescent intensity (FI), also were greater (P less than 0.05 and P less than 0.01) following static culture than for embryos cultured in the perifusion system. Four of 9 control embryos resulted in pregnancies but no embryos cultured in either system prior to transfer resulted in pregnancies. Three of 9 embryos in the static treatment group and 1 of 9 embryos in the perifusion group resulted in non-ecogenic vesicles. Ultrastructural evaluation agreed with FD scores and morphological assessment. The continued development of static cultured embryos without the presence of an inner cell mass (ICM) was supported by ultrasound data.