Superovulatory and embryo yielding in sheep using increased exposure time to progesterone associated with a GnRH agonist

•We examine prolonged exposure to progesterone in superovulation protocol.•We examine prolonged exposure to progesterone plus GnRH in superovulation protocol.•Longer progesterone exposure tended to reduce the degenerate embryos rate.•Longer progesterone exposure plus GnRH administration increased fertilization rate.