EPF as a Marker for Early Embryonic Losses in Repeat Breeders

Abstract

Early pregnancy factor (EPF) is detectable in sera of pregnant cattle within 24 to 48 h after fertilization. It has been considered that the repeat breeder is relatively sterile as a result of fertilization failure and the early embryonic loss. This study used the rossete inhibition test to clarify whether repeat breeding is a result of early embyronic loss. We measured serum EPF in cattle that were diagnosed as repeat breeders to examine the incidence of early embryonic losses after artificial insemination (AI) (n=20). There were no significant differences in the presence of EPF on day 3 after AI for 20 repeat breeders and controls. Furthermore, EPF-positive rates decreased about 60% by day 21 after AI for both repeat breeders and a control group. It is suggested that a high incidence of early embryonic losses takes place in cattle, and we attempted embryo transfer (ET) as the treatment of choice.