Effect of different egg yolk sources on dog semen quality following cryopreservation

The aim of this study was to compare the cryoprotective effects of egg yolk from different avian species (hen, goose and quail) on post-thaw quality of dog semen. Total motility (TMOT) and progressive motility (PMOT) of frozen-thawed spermatozoa were not significantly differed among the extenders, but were higher in the quail-egg yolk based extender compared with extender containing hen or goose egg yolk. It was found that post-thaw sperm motion parameters, velocity VCL and ALH, were significantly higher in the quail-egg yolk based extender. No marked differences in post-thaw sperm plasma membrane integrity (PMI) and mitochondrial membrane potential (MMP) were observed among the extenders. In conclusion, the results of the present study suggest that goose or quail egg yolk is a suitable alternative to hen egg yolk for the cryopreservation of dog semen

The effect of two packaging systems on the post-thaw characteristics of canine sperm

The aim of this study was to compare the effect of different packaging systems on some parameters of cryopreserved canine spermatozoa. The experimental material consisted of the sperm-rich fractions of ejaculates collected from four Beagle dogs. Semen samples for cryopreservation were stored in 0.25 ml plastic straws and two aluminum tubes with a total volume of 5.0 ml. Semen was frozen in static nitrogen vapor for 10 minutes (0.25 ml straws) or 15 and 20 minutes (aluminum tubes). Post-thaw assessments involved the determination of sperm motility parameters using a computer assisted sperm analyzer (CASA), sperm plasma membrane integrity (SPMI), mitochondrial membrane potential (MMP) and acrosome integrity (normal apical ridge, NAR). Regardless of the packaging system applied, no significant differences in total sperm motility (TMOT) or selected kinematic parameters were observed after freezing-thawing. However, spermatozoa frozen in 0.25 mL straws were characterized by improved functionality, in particular mitochondrial function, after thawing. The results indicate that large quantities of canine semen can be frozen in aluminum tubes. Further studies are required, however, to evaluate different freezing and thawing rates of aluminum tubes