Fertility studies in young and mature merino ewes 2. Sperm transport

Samples of cervical mucus were collected from young and mature ewes at different stages of oestrus. The migration rate of spermatozoa (time taken to travel 410 mm) was not different in samples of mucus from young and mature ewes. Spermatozoa were unable to penetrate the mucus in 7 27 samples, five of which were collected about 16 hours after onset of oestrus. Migration rate in samples collected between 10 and 16 hours after onset of oestrus was significantly slower than in samples collected in the first five hours of oestrus. The transport of spermatozoa in young and mature ewes was also studied by observing distribution of spermatozoa in the female genital tract 26 to 27 hours after hand-mating. There were no significant differences between young and mature ewes either in mean sperm count or in variation of mean sperm numbers in all sections of the tract.