Effect of different extenders for donkey sperm vitrification in straws

Aseptic vitrification of semen samples packed in straws has been successfully developed in human but not in donkeys. The aim of this study was to compare the effect of two extenders for donkey sperm vitrification using straws. Ejaculates from four Andalusian donkeys were collected, and samples were extended in INRA-96 (I) or Gent (G) supplemented with sucrose 0.25 M and 1% bovine serum albumin (BSA). Extended samples were cooled for one hour at 5°C. For vitrification, samples were filled in covered 0.25 ml straws and then plunged directly into liquid nitrogen. For warming, straws were immersed in INRA-96 at 43°C. Results showed no significant differences between I and G treatments for TM (34.2% ± 8.7 vs. 30.7% ± 9.6) and PM (26.8% ± 7.3 vs. 24.6% ± 7.9), respectively. In conclusion, donkey sperm could be vitrified in straws either with INRA-96 or with Gent in combination with sucrose and BSA.