Rate of establishment of a fertilising population of spermatozoa in the sheep cervix after a single mating at the onset of oestrus.
In order to study how soon a population of spermatozoa capable of fertilisation could progress into the cervical canal, the vaginal contents were flushed with a detergent solution at different intervals after mating at the onset of oestrus. Eggs recovered 1 or 2 days later from the oviducts were stained and examined by phase-contrast microscopy. Flushing at 3 minutes after mating did not prevent fertilisation in 44% of instances, whereas similar flushes performed at 6 or 9 minutes completely prevented fertilisation in a total of 26 animals. In the groups flushed at 12 and 15 minutes, the proportion of eggs fertilised was 21% and 24%, respectively, and this increased to 37% after flushing at 18 minutes. An explanation is offered for the paradoxical finding at 3 minutes, and it is concluded that at least 30-60 minutes would be required for adequate colonisation of the cervix with a fertilising population of spermatozoa under the conditions employed in the experiment. However, multiple matings or mating closer to the time of ovulation might act to reduce this interval.
School of Agriculture, University of Edinburgh, Scotland, United Kingdom.
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Hunter
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Nichol
D000818:Animals; D002584:Cervix Uteri / Q000166:cytology*; D004971:Estrus / Q000502:physiology*; D005260:Female; D005306:Fertilization / Q000502:physiology*; D008297:Male; D012756:Sheep; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D013997:Time Factors