Canine semen's freeze with different concentrations of egg yolk and glycerol in tris and coconut wateer extenders

The aim of the present research was to compare the efficiency of coconut water and Tris extenders on canine semen freezing. The semen from 5 German Shepherd dogs was collected by digital manipulation. The spermatic fraction of different dogs was evaluated about its macro and microscopic parameters and mixed in a pool. It was extended in coconut water or Tris, added of egg yolk (10 or 20%) and glycerol (4, 6 or 8%). Then, it was frozen by the method of NUNES et al. (1997) and thawed at 37ºC after one week. A Tris extender superiority was shown at the conservation of vigor (2.3 ± 0.8), total (14.8 ± 5.1%) and secondary (14.4 ± 5.5%) spermatic defects in the protocols with 20% of egg yolk and 6% of glycerol. In all other protocols, there were no significant differences for the observed parameters. These results suggest a superiority of Tris extender over the coconut water extender on canine semen freeze, in the use of them added of 20% of egg yolk and 6% of glycerol.

semen; dog; freeze; coconut water; Tris; glycerol; egg yolk