PROSTAGLANDIN-F2-ALPHA METABOLITE AND PROGESTERONE PROFILES IN POSTPARTUM COWS WITH RETAINED FETAL MEMBRANES

Post-partum prostaglandin release and resumption of cyclical ovarian a ctivities were studied in 11 Swedish dairy cows with retained foetal m embranes (RFM), leaving the RFM untreated. The main PGF(2 alpha) metab olite, 15-ketodihydro-PGF(2 alpha) was measured in blood plasma collec ted twice daily during the first 50-60 days after delivery Progesteron e was monitored from all morning samples to evaluate the resumption of ovarian activity. The plasma levels of 15-ketodihydro-PGF(2 alpha) we re arbitrarily considered to be significantly elevated between 6-24 da ys when they exceeded the mean basal value + 2 standard deviations. Co mparison between this duration in days of the post-partum PGF(2 alpha) release and the time required for the completion of uterine involutio n, placental shedding and last day of post-partum clinical signs showe d no significant relations. However, prior to a final decrease below a line of significance of 233-590 pmol/l, pronounced sustained and puls atile release of PGF(2 alpha) occurred in relation to the increased fr equency of the bacteriological findings. These additional periods of P GF(2 alpha) release were described as the ''total'' duration of post-p artum release, and were found to be positively correlated with the tim e required for uterine involution from the stand point of rectal palpa tion (p<0.05), while a tendency towards a positive relationship existe d for the last day post-partum of clinical signs (p=0.11). Progesteron e analysis revealed resumption of ovarian activity and the first ovula tion occurred between 19-29 days in 70% of the cows. The levels of the PGF(2 alpha) metabolite were again high at the time of luteolysis, th us terminating the luteal phase in the ovulating animals. Thus, it is seen that non-removal of the RFM or the resultant intrauterine infecti on do not prolong the duration of the immediate post-partum release of PGF(2 alpha) as compared to normal animals. However, a second release is associated with the increased frequency of uterine infections, ind icating that PGF(2 alpha) may play a role for the early elimination of the infections.