A donkey infertility was described by transmission electron microscopy (MET). The spermiogram evaluated by light microscopy showed low sperm motility and high concentration of abnormal sperm with proximal cytoplasmic droplets. The material was evaluated by MET, where it was observed disarrangement of microtubules, causing irregular protrusions in the spermatic neck. The last test done was the in vivo fertility, using four mares, with a reproductive healthy historic, where no pregnancy occurred. Facing the results that we had in vivo, associated with the MET findings, we diagnosed infertility associated with microtubular defect of the spermatozoa.
donkey; spermatozoa; microtubular defect; electron microscopy; infertility
