Repeated trans-cervical embryo recoveries in Santa inês ewes subjected to short- or long-term superovulatory treatment regimens.
Outcomes of short- (6.5 days) and long-term (14.5 days) estrous synchronization for 6.5 d (G-6.5d) or 14.5 d (G-14.5d) and followed by the 4-day or 3-day declining-dose follicle-stimulating hormone superovulatory regimen, respectively, were compared using 16 estrous-cycling Santa Inês ewes. Non-surgical embryo recovery (NSER) procedures were performed 60 d apart starting 6 or 7 d after the onset of estrus; an i.m. injection of estradiol benzoate and of d-cloprostenol at 16 h was followed by an i.v. oxytocin injection administered 20 min before NSER. There was a longer (P < 0.05) period before estrous onset in ewes during the second (September) compared with the first study replicate (July) by approximately 14 h. The NSER could be performed in 11 of 15 ewes that were in estrus, with an average of three viable-embryos/donor and the mean duration of the procedure being 29 min. There were no differences in superovulatory responses between the two groups of ewes, but there were only degenerated embryos in ewes of the G-6.5d group. In summary: i. the duration of progestin-priming and of multiple-dose pFSH treatment had a limited effect on superovulatory responses in estrous-cycling Santa Inês ewes; ii. NSER is a safe and repeatable method of embryo collection in ewes subsequent to superovulation; and iii. duration of the superovulatory treatment regimen may alter the effects of endogenous steroids on oocyte/embryo quality in ewes.
['Oliveira|M E F|MEF|', 'Zambrini|F N|FN|', 'Souza-Fabjan|J M G|JMG|', 'Bartlewski|P M|PM|', 'Guimarães|J D|JD|', 'Brandão|F Z|FZ|', 'Fonseca|J F|JF|']
D000818:Animals D006063:Chorionic Gonadotropin D003008:Cloprostenol D004624:Embryo Transfer D004622:Embryo, Mammalian D004973:Estrus Synchronization D005260:Female D005640:Follicle Stimulating Hormone D017258:Medroxyprogesterone Acetate D011247:Pregnancy D012756:Sheep D013480:Superovulation D020858:Tissue and Organ Harvesting
Estradiol Superovulation Progestin Sheep Trans -cervical uterine flushing