Administración posmonta de acetato de fluorogestona en ovejas donadoras de embriones

Abstract

THE NUMBER OF NORMAL AND REGRESSING CORPORA LUTEA AND OF RECOVERED OOCYTES AND EMBRYOS WERE ANALIZED IN TWO STUDIES WHERE DONOR EWES WERE TREATED AFTER MATING WITH FLUOROGESTONE ACETATE (FGA). ESTROUS WAS SYNCHRONIZED WITH 40 MG OF FGA IMPREGNATED INTRAVAGINAL SPONGES, AND SUPEROVULATION WAS ACHIEVED WITH 200 UI OF FOLLICLE STIMULATING HORMONE IN A DECRECIENT SCHEME. EWES THAT SHOWED ESTROUS WERE MATED WHILE RECEPTIVE. TWELVE HOURS AFTER THE LAST MATE, ANOTHER INTRAVAGINAL SPONGE WAS APPLIED TO HALF OF THE EWES IN THE FIRST STUDY AND TO ALL IN THE SECOND ONE, WHICH WAS REMOVED ON THE DAY OF EMBRYO COLLECTION. CORPORA LUTEA WAS CLASSIFIED AS NORMAL OR REGRESSING ACCORDING TO MORPHOLOGY AND PROGESTERONE PRODUCTION. IN THE FIRST STUDY, MORE EMBRYOS WERE RECOVERED FROM FGA TREATED EWES THAN FROM THOSE NOT TREATED ONES (7.66 VS 3.87, P<0.05). LOWER PROGESTERONE CONCENTRATION WAS FOUND IN EWES WITH REGRESSING CORPORA LUTEA (0.62 NG/ML). ACCORDING TO PROGESTERONE LEVELS, EARLY CORPUS LUTEUM REGRESSION OCURRED AT 3.7 DAYS AFTER ESTROUS. IN THE SECOND STUDY AN AVERAGE OF 8 EMBRYOS WERE COLLECTED FROM FGA TREATED EWES THAT HAD REGRESSING CORPORA LUTEA. IN CONCLUSION, FGA ADMINISTRATION AFTER MATING INCREASED EMBRYO RECOVERY IN DONORS WITH EARLY REGRESSING CORPORA LUTEA.