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.
Hunter
R H
RH
School of Agriculture, University of Edinburgh, Scotland, United Kingdom.
Nichol
R
R
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