Objectives of this study were to show postpartum plasma
PGF2 alpha metabolite (
PGFM) profile, to clarify whether endogenous
PGF2 alpha plays a certain role in the uterine involution in cows with
dystocia and/or
retained placenta, and to examine the effects of
fenprostalene, a long-acting
PGF2 alpha analog, on the uterine involution and reproductive performance of the cows with abnormal puerperium. A group of 27 cows with
dystocia and/or
retained placenta showed a massive release of
PGF2 alpha after parturition as indicated by a rise of plasma concentrations of
PGFM, significantly higher than 33 cows with normal puerperium. The duration of the elevated plasma
PGFM concentrations in the cows with abnormal puerperium was shorter than that of the normal cows. In cows with normal puerperium, those showing relatively longer duration of elevated plasma
PGFM levels needed a shorter period for postpartum uterine involution than the cows showing a shorter duration of the
PGFM elevation (P < 0.01), while no such relationship was observed in cows with abnormal puerperium. In field trials, an administration of an exogenous
PGF2 alpha,
fenprostalene, at 7 to 10 days (78 cows) or 14 to 28 days postpartum (74 cows) was found to be effective in facilitating uterine involution and resumption of ovarian cyclicity, and improved reproductive performance. It may be concluded that a large amount of
PGF2 alpha is released for a relatively shorter period in cows after
dystocia and/or
retained placenta and the elevation of
PGFM is not responsible for the uterine involution. The administration of the exogenous
PGF2 alpha was shown to be effective at improving the postpartum reproductive performance of cows with abnormal puerperium.