The use of prostaglandins and oxytocin for transcervical recovery of bovine fetuses at days 33-58 of gestation

Abstract

The study of bovine germ cells of known developmental stage calls for alternatives to the recovery of fetuses by surgery or slaughter. Fetuses were therefore obtained during the second month of pregnancy by aborting 49 animals using a progressively modified treatment regimen of cloprostenol, prostaglandin E2 (PGE2) and oxytocin. The viability of fetuses was monitored by ultrasonography throughout treatment. Intracervical treatment with PGE2 led to cervical dilation in all treated animals. However, retrieval of the fetuses by subsequent flushing of the uterus was successful in only two of six animals. When i.m. injections of cloprostenol were given 20-40 h before PGE2 treatment, fetuses ≤ 40 days of gestation were expelled spontaneously, while the majority of fetuses ≥ 50 days of gestation were retained. When i.m. injections of oxytocin were given in relation to clinical signs of impending fetal expulsion after cloprostenol and PGE2 treatment, 20 of 22 fetuses were expelled 42-53 h after the cloprostenol injection. Of these 20 fetuses, 19 were expelled 0-7 h after the cessation of fetal heartbeat. The subsequent fertility of animals was not affected. Thus, the final protocol allowed bovine fetuses to be retrieved at predictable times, within a few hours of death, with little maternal trauma and without affecting subsequent fertility.