Abstract
The viability of embryos transferred to 37 cows were monitored by detecting early pregnancy factor (EPF) in the bovine serum. Embryos were transferred nonsurgically to the uterine horn ipsilateral to the ovary bearing the corpus luteum on day 7 to day 11 (day 0=day of estrus). The transferred embryos included 33 in vitro fertilized embryos; 3 fresh embryos, 24 freezed embryos, 6 freezed, thawed and cultured embryos, and 4 in vitro fertilized embryos which were freezed and thawed. Blood samples were collected weekly after the embryo transfer for the EPF assay and progesterone determination. Total pregnancy rate on day 42 to 43 obtained by ultrasonographic examination was 18.9%. Percentage of cows with viable embryo on 7 and 28 days after the transfer was 59.5% and 18.9%, respectively. This discrepancy indicated the occurrence of embryonic death. All 7 cows in which EPF was detected on 28 days after embryo transfer were diagnosed with ultrasonographic examination as pregnant on 35 days after the transfer. Determination of EPF in the serum is proved to be useful for monitoring the viability of the transferred embryo.
