The development of sperm freezing can significantly help conservation and management of the endangered African wild dog. With the development of a good freezing protocol, sperm banks can be set up, both from captive as free-living populations.
This way, we can provide a genetic back-up of the current population, which gives a buffer against possible threats such as fires or a sudden epidemic of infectious disease outbreaks both in captivity and in the wild. In addition, sperm freezing enables easy world-wide transport of genetic material.
Artificial insemination (AI) has the potential to overcome the high levels of intra-pack aggression often associated with translocation and introduction of new genetically valuable animals within an existing stable pack. Moreover, transportation of semen instead of living animals to infuse new genes into a group is cheaper, avoids the removal of animals from established wild packs, and can also decrease the incidence of disease transmission.
These techniques could also be used for broader meta-population management, to avoid inbreeding in fenced reserves that are smaller than the range required for African wild dog populations to be self-sustaining, or in cases where natural dispersal is limited.
However, previous attempts to freeze sperm from the African wild dog have proven unsuccessful. In these studies, sperm motility dropped to nearly 0% within 2 hours after thawing, which means that pregnancy after AI using these sperm cells is highly unlikely.
To try and improve these results, we tested 2 different freezing protocols based on protocols that are commonly used in the domestic dogs. One of these protocols showed very exciting results. Most sperm quality parameters after thawing where similar to results seen in the domestic dogs, where pregnancy rates after AI are relatively high. Sperm motility was even present up to 8 hours after thawing, making this protocol a suitable candidate for the development of sperm banks and artificial insemination!
These results have been presented at the 18th International Congress on Animal Reproduction (ICAR, 26-30 June 2016, Tours, France) and the EAZA 2017 Annual conference (19-23 September 2017, Emmen, The Netherlands). The full study has recently been submitted for publication and will be available soon.