Cryopreservation of canine semen in pellets and in 5-ml aluminum tubes using three extenders

Abstract

Successful cryopreservation of canine semen depends on the method of collection, composition of the cryoprotective medium and type of packaging. We wished to compare efficacy of packaging canine semen in aluminum tubes vs the commonly used method of pelleting on dry ice. A total of 11 ejaculates from 5 dogs was divided among 3 extenders, Tris-glucose (TG), Tris-fructose (TF) and Lactose (L) and between 2 packaging methods, pelleting or aluminum tubes. Upon thawing, spermatozoa from samples extended in lactose and frozen in aluminum tubes showed the best motility (36%), highest percentage of intact acrosomes, and the second-best survival rate (256 min), resulting in an overall best performance for this combination of extender and packaging method. The two-factor factorial analysis of variance demonstrated statistically significant effects of both the cryoprotective extenders and the packaging on sperm motility and survival (P < 0.01), as well as of the packaging methods on sperm cell structure (P < 0.001).