ABSTRACT
The objective of this work was to evaluate the recovery of epididymal spermatozoa from castrated dogs using retrograde flow (FL) and flotation (FL) techniques in Tris-egg yolk diluent, before and after cryopreservation. Thirty testicle-epididymal complexes (CTE) were collected, 15 for FR and 15 for FL and soon after spermatozoid recovery, morphological changes in these spermatic cells were analyzed. After addition of the diluent, the parameters of total motility (MOT) and vigor (V) were evaluated. The post-cryopreserved semen was submitted to thermoresistance (TTR) test at T0, T30, T60 and T90 minutes, as well as the plasma and acrosomal membrane evaluation by fluorescent probes. There was no statistically significant difference between techniques tested for MOT and vigor in the diluted semen (FR-MOT: 82.3% and V: 3.4, FL-MOT: 79.6% and V: 3.2) and post-cryopreserved (FR-MOT: 34% and V: 2.8, FL-MOT: 30% and V: 2.7). From the T30 there was a significant difference regarding MOT and vigor in the used techniques, and the time also damaged the spermatic acrosome from the T30. It is concluded that the epididymal spermatozoa recovering techniques from castrated dogs, tested in this study, can be used for semen refrigeration and cryopreservation.
Keywords:
canine; epididymis; flotation; retrograde flow; semen