Evaluation of a segmented rectal probe and caudal epidural anesthesia for electroejaculation of bulls

Changes in concentrations of cortisol and progesterone in serial blood samples were used to quantify a stress response to different methods of electroejaculation in 10 Hereford bulls. Treatments included restraint (control), and electroejaculation using rectal probes with segmented electrodes or conventional nonsegmented electrodes, with or without lidocaine caudal epidural anesthesia. A subjective scoring system was used to assess behavioral responses to the different methods of electroejaculation. The increases in concentrations of serum cortisol and progesterone after electroejaculation were higher for all electroejaculation treatments than for restraint alone. The increases in serum progesterone concentrations were significantly lower at 5 and 20 minutes after electroejaculation with epidural anesthesia than with no anesthesia. However, the change in cortisol or progesterone concentrations did not differ after electroejaculation when comparing the conventional probe or a segmented probe at any time during the study. Subjective scoring showed no differences among electroejaculation methods. Use of epidural anesthesia was beneficial in reducing progesterone, one indicator of an endocrine stress response to electroejaculation.