title: Time required for spermatozoa to remain in the vagina of the ewe to ensure conception.
abstract: Oestrous ewes (N = 202) were inseminated with 0.1 ml of semen containing 500 X 10(6) motile spermatozoa and the spermatozoa were flushed from their vagina either immediately or 0.25, 0.5, 1, 2, 4 and 8 h after insemination. Pregnancy was determined by returns to service and laparoscopy. Some ewes became pregnant (10.71%) after spermatozoa had been flushed from the vagina only seconds after insemination and about 40% of ewes became pregnant after spermatozoa had been in the vagina for 15 min. Maximum conception (55%) was achieved when spermatozoa had been in the vagina for at least 2 h. It was concluded that the losses of spermatozoa that occur from the vagina will not influence the chance of a ewe conceiving because sufficient spermatozoa to ensure a normal conception move up the reproductive tract before large losses from the vagina take effect.
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization; D008297:Male; D011247:Pregnancy; D011897:Random Allocation; D012756:Sheep / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology*; D013997:Time Factors; D014621:Vagina / Q000502:physiology*