Deep-horn Artificial Insemination with Frozen Thawed Semen after re-extension in Autologous Seminal Plasma May Improve Pregnancy Rates in Jennies

In the literature, the very low pregnancy rates after artificial insemination (AI) with frozen semen in donkeys were improved in one study after re-extension of the frozen‐thawed semen in autologous seminal plasma. The aims of our study were i) to describe in vitro post-thaw parameters of donkey jackass semen after re-extension in seminal plasma (SP) or in INRA96 and ii) to compare pregnancy rates in jennies bred with frozen-thawed semen using two different AI protocols. Semen collected from two Amiata donkey stallions, known to be fertile, was frozen in INRA96 supplemented with 2% egg yolk and 2.2% glycerol. From the same jacks, seminal plasma was filtered and stored at -20°C. According to the in vitro analysis, the post-thaw re-extension in SP some kinematic parameters decreased more over time. Two different AI protocols were tested: inseminating deeply into the uterine horn (DHAI) with or without thawed semen re-extension in SP. Higher pregnancy rates were obtained with re-extension in SP than when AIs were performed without SP. Further studies are needed to confirm the advantage of re-extension in autologous SP of donkey frozen-thawed semen before AI in jennies.