Prostaglandin F2α and progesterone in experimental hypogalactia in sows

Abstract

Peripheral plasma concentrations of total oestrogens, total corticosteroids, progesterone and 13,14-dihydro-15-keto-prostaglandin F2α (PGFM) were determined in eight sows for one week before and three weeks after parturition. Two sows each received one of the following four treatments post partum: 30 ml sterile, 0·9 per cent saline solution intrauterine!}; 10 ml Lugol’s iodine plus 20 ml saline solution intra-uterinely; 100 mg of indomethacin in 30 ml saline solution intrauterinely; an intramuscular injection of 6 mg of prostaglandin F2α (PGF2α) during intrauterine iodine treatment. Beginning after the completion of parturition, saline solution and iodine were injected at 48 h intervals and indomethacin was given daily. Piglet weight gains «ere used as a reflection of milk yield. In all sows, oestrogen values rose at the end of pregnancy to reach a peak just before parturition. These values fell by the end of delivery and were very-low during lactation. Corticosteroid concentrations fluctuated markedly before farrowing and during lactation for all sows. A sharp drop in progesterone values occurred in the two days before parturition, but after delivery values varied among sows depending upon the treatment. For control sows receiving intrauterine injections of saline, progesterone levels completed their decline shortly after farrowing and remained very low during the nursing period. When iodine or indomethacin was administered to sows, progesterone values did not complete the decline post partum, but varied between 1 and 4 ng/ml plasma. Weight gains of piglets for sows on these two treatments were significantly less than for those of control sows. When PGF2α was injected on day 4, the somewhat elevated progesterone values (1 to 4 ng/ml) declined to concentrations of 150 to 300 pg ml plasma for the rest of lactation. Piglet weight gains in this group were similar to those of piglets nursing on control sows. PGFM concentrations rose to a peak of 15 to 30 ng/ml plasma at farrowing. These values appeared to drop more rapidly post partum in sows receiving iodine or indomethacin injections than in sows receiving saline solution injections. The results suggest that iodine or indomethacin treatment inhibited the post parturient production of PGF2α by the uterus so that complete luteolysis and a further decline in progesterone values did not take place. A relationship may therefore exist between the uterus and hypogalactia in the metritis-mastitis-agalactia syndrome of the post parturient sow.