Abstract:
Ewes in a synchronized oestrus wereinseminated (intrauterine) with fresh and frozen-thawed spermatozoa andthe spermatozoa were either recovered from each section of the reproductivetract after the animal was killed (Experiments 1a and 1b) or after they werevoided from the cervix (Experiment 2). In Experiment 1a, only 1.2 0.27%of the original inseminate was recovered. Placing a ligature at the base ofthe uterine horn in Experiment 1b led to the recovery of 3.0 0.33% ofthe original inseminate, located mainly in each uterine horn (33.15.48%), and each isthmic and ampullary region of the oviduct (2.95.48% and 4.0 5.48%, respectively). A higher proportion ofspermatozoa recovered from the isthmus were uncapacitated when observed bychlortetracycline staining than those recovered from the uterus (26.41.92% and 15.6 1.92%, respectively,P<0.05). Experiment 2 showed that large proportionsof spermatozoa were voided from the tract through the vagina, with similarnumbers of fresh and frozen-thawed spermatozoa lost from the tract.However, frozen-thawed spermatozoa were lost at a faster rate than fresh(P<0.05) and with a more advanced membrane state(66.8 1.30% and 53.2 1.30% were acrosome reacted respectively;P<0.001). Large numbers of recovered spermatozoa hadlost their tails, with frozen-thawed spermatozoa more susceptible totail loss than fresh spermatozoa (55.0 0.96% and 45.5 0.96%respectively; P<0.05).