A study on two extenders on canine semen was performed, in order to evaluate their effects on in vitro characteristics of cryopreserved spermatozoa. The extenders studied were Tris-citrate and Tes-Tris. Semen from three stud dogs was collected weekly during five weeks for the experiment protocol. Semen samples were examined for sperm motility and forward progression, and plasmatic membrane and acrosome integrity using the hypo-osmotic swelling test and phase contrast microscopy, respectively, and semen longevity using the thermo-resistance test. A comparative analysis between the extenders has showed that Tris-citrate was superior (P<0.05) as compared to Tes-Tris based on the results of the hyposmotic swelling test, thermo-resistance test, sperm motility, forward progression and achrossome integrity after cryopreservation, all values 15% higher for the Tris-citrate
Dog; semen; extender; cryopreservation
