Method of euthanasia does not affect sperm motility in the laboratory rat.

To determine if anesthetic agents used in laboratory animal euthanasia affected sperm motion parameters, rats (n = 10 per group) were euthanized by one of 5 different methods: decapitation alone, or decapitation following either ether, halothane, or Nembutal anesthesia, or CO2 asphyxiation. Sperm were collected from the distal cauda epididymis, diluted, and videotaped for computer-aided sperm analysis (CASA; HTM-2030, Hamilton-Thorn Research, Beverly, MA). The percentage of motile sperm (MOT), their straight-line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), linear index (LINX), and linearity (LIN) were measured on > or = 200 motile sperm per sample. No significant differences in any of these 6 motion parameters were found among the treatment groups. Thus, none of these 5 methods of euthanasia affect sperm motion as assessed by CASA methods, making them equally suitable for use in reproductive toxicology studies.