Reduction of sperm transport in ewes by superovulation treatments

Abstract

At 24 h after insemination one uterine horn and one oviduct were flushed for recovery of spermatozoa and ova. When compared with naturally cyclic ewes, PG synchronization resulted in a marked reduction in the numbers of spermatozoa recovered (P < 0\m=.\05), and sponge synchronization led to a small, non-significant, reduction. Within the synchronized ewes, PMSG and FSH resulted in an equivalent superovulatory response, but there was a marked reduction in sperm recovery when compared with unstimulated animals (P < 0\m=.\01),with the greatest reduction attributable to PMSG treatment. Spermatozoa were recovered from fewer ewes treated with PMSG than with FSH (P < 0\m=.\05).Despite the observed impairment of sperm transport, a high fertilization rate was observed within each group and there were no differences between treatments.

Intrauterine insemination enhances fertility of frozen semen in superovulated ewes

“…Alternatively, it may be a reflection of earlier ovulation in ewes with higher ovulatory responses to the gonadotrophin. Time of ovulation in relation to progestagen withdrawal has been shown previously to be advanced by treatment with PMSG (Killeen & Moore, 1970) and FSH (Evans & Armstrong, 1984).…”

“…Numbers of spermatozoa recovered from uteri and oviducts of ewes 24 h after cervical insemination were markedly decreased by superovulatory hormone regimens (Evans & Armstrong, 1984), and significant improvement of fertilization rate in superovulated ewes has been reported after intrauterine insemination with fresh semen (Trounson & Moore, 1974).…”

Ovarian Response to PMSG Treatment in Ewes Immunized against Oestradiol-17ß

“…Our results are equivocal concerning this question as there was a lower fertilization rate in response to greater PMSG stimulation but the higher levels of antibody did not redress this problem. Evans and Armstrong (1984) found decreased sperm numbers in the oviducts of ewes treated with PMSG although this did not appear to impair the rate of fertilization.…”

Cryopreservation of Sheep Produced Embryos – Current and Future Perspectives

“…Anovulation has been described as one of the main reasons for fertilization failures, especially due to the associated higher estradiol concentrations [87], influencing the uterine environment and affecting oocytes [89] and spermatozoa [90] transport. However, other authors described no effect of these anovulatory follicles [91].…”