Abstract
The present study was conducted to find out the changes of progesterone levels in pre and post partum by the PGF2$\alpha$ administration to control artificial parturition in Korean native goats. A total of 24 goats were offered for this experiment. The animals were divided into 4 goats per treatment by the administration time(142, 145 or 148 day of pregnancy). Blood samples were taken from jagular vein pre-post partum by the PGF2$\alpha$ intramuscular administration. The progesterone in serum was assayed by radioimmunoassay. The serum progesterone level in late-pregnant goats averaged 4.85$\pm$0.55ng/ml, 4.05$\pm$0.47ng/ml or 2.76$\pm$0.25ng/ml on 142, 145 or 148 days of gestation. After the intramuscular injection with PGF2$\alpha$ for inducing parturition, it decreased remarkably to below 1.0ng/ml and to the base level(0.4~0.6ng/ml) at day 1 after parturition. And then this base level of progesterone was maintained until the final examination at 9 days of postpartum. No significant difference was found in the serum levels of progesterone between the doses treated for parturition induction. It was concluded that exogenous PGF2$\alpha$, administrated intramuscularly, induced premature parturition with causing withdrawal of progesterone levels for triggering luteolysis.
