Cryopreservation of canine semen after cold storage in a Neopor box: effect of extender, centrifugation and storage time

The aim of this work was to assess the combined effect of sperm centrifugation, semen extender and storage time before freezing on post-thaw sperm quality and freezability on chilled stored canine semen in a Neopor box. Sperm parameters evaluated were total and progressive sperm motility by Computer-Assisted Sperm Analysis (CASA) and sperm viability and acrosome integrity using a triple fluorescent stain. Sperm quality and freezability indexes were also studied. First, the effect of centrifugation and two commercial extenders from Minitube (Biladyl A and CaniPRO Freeze A) was evaluated in chilled semen after 24 and 45 hours of cold storage. No significant differences were observed between treatments in almost all the sperm parameters assessed. Secondly, chilled semen was frozen after 24 and 45 hours of cold storage in a Neopor box. The best results were obtained when semen was centrifuged, chilled with CaniPRO Freeze A and then frozen after 24 hours of cold storage, showing no differences in both post-thaw sperm quality and freezability in comparison with semen immediately frozen after collection. In conclusion, dog semen centrifuged after collection and extended with CaniPRO Freeze can be frozen after 24 hours of cold storage in a Neopor box, obtaining similar results to semen immediately frozen after collection.