Position Statements

Electroejaculation of Cattle, Sheep, and Goats

April 1, 2025

Position statements developed by the CVMA reflect current knowledge regarding animal welfare.
While they are not legislative, they do represent CVMA’s ongoing commitment to the advancement
of animal welfare.

Position

The Canadian Veterinary Medical Association (CVMA) considers electroejaculation of cattle, sheep,
and goats a veterinary procedure due to the potential for adverse animal welfare. Veterinary skills
are required: to determine the suitability of the animal for the procedure; to ensure appropriate
restraint; to ensure appropriate selection and operation of the equipment; and to monitor the
responses of the animal to the procedure in an effort to minimize the stress and potential pain
associated with electroejaculation.

Summary

  • In all cases where electroejaculation is employed, it should be performed by a veterinarian or under the supervision of a veterinarian.
  • Although electroejaculation is a quick and reliable method for the collection of semen, whenever possible alternative procedures should be considered that cause less pain and discomfort than electroejaculation.
  • Electroejaculation has the potential to cause discomfort, especially if the procedure is not conducted appropriately.
  • Where there are no practical alternatives to electroejaculation, the procedure must be undertaken in a manner that minimizes pain discomfort.

Background

  1. The electroejaculation procedure involves insertion of a probe into the rectum and application of short, low-voltage pulses of electrical current to the pelvic nerves that stimulate smooth muscles of the ampullae and ductus deferens to induce ejaculation.
  2. Electroejaculation is most commonly used to collect semen as part of a breeding soundness examination (1), which is undertaken to determine the fertility of an individual. Electroejaculation is also used for purposes other than breeding soundness examinations such as semen collection for breeding (artificial insemination) and gene banking. It is also currently performed in other species not addressed in this position statement.
  3. Electroejaculation is a reliable method for semen collection that can be performed outside of the breeding season on animals that have not be trained using an artificial vagina, and on animals that are not accustomed to individual handling. Compared to the use of an artificial vagina, it is easier to ensure human and animal safety, and teaser animals are not required for mounting, thus reducing the risk of disease transmission (2). Semen can be collected by transrectal massage in bulls, but in a large proportion of bulls there are reductions in sperm motility and in live sperm and the ability to examine the penis is reduced. (3)
  4. Electroejaculation has the potential to cause discomfort, especially if the procedure is not conducted appropriately (4,). The NFACC Codes of Practice for the Care and Handling of Sheep and of Goats (5,6,) both state in their requirements that electroejaculation of rams and bucks is a procedure that must only be performed by a licensed veterinarian.
  5. Research indicates that electroejaculation is an aversive experience, and research has identified signs that indicate the potential for rams, bucks and bulls to experience discomfort, pain or distress with electroejaculation (7-16). These responses to electroejaculation are primarily due to electrical stimulation rather than as a consequence of ejaculation (12), restraint, or insertion of the rectal probe (8, 11).
  6. Whenever possible, a less invasive procedure e.g., an artificial vagina (that in many circumstances is able to produce similar or better results) or transrectal massage (17) should be used for semen collection in preference to electroejaculation. Where there is no practical alternative to electroejaculation, the procedure must be undertaken in a manner that minimizes pain and discomfort (18).
  7. Veterinary professionals intending to use electroejaculation should have sufficient training in the use of this procedure. Prior to electroejaculation, the animal must be examined to determine its suitability for the procedure and indications for analgesia and chemical restraint should be evaluated. The animal must be restrained in a manner that minimises the risks of stress and injury. Gentle handling, habituation to the collection area and positive reinforcement such as feeding can reduce stress (19). Care is required to ensure that the anus and rectum are prepared prior to insertion of an appropriately sized and prepared probe. The equipment used must be in good working condition and be operated in a manner that uses the minimum electrical stimulation sufficient to produce an ejaculation (13). If after repeated electrical stimulation, the procedure fails to produce an ejaculate, or if the animal becomes distressed, or is at risk of injury, the procedure should be terminated, and the animal not electroejaculated for an appropriate period as determined by the attending veterinarian.
  8. Research to reduce the discomfort of electroejaculation has evaluated both analgesics and methods of reducing the intensity and/or duration of electrical stimulation required to obtain an ejaculate. Bulls displayed a reduction in the behavioural signs of discomfort during electroejaculation after administration of epidural xylazine (20) and a reduction in serum progesterone (a stress marker) with lidocaine epidural (21). Epidural anaesthesia does not interfere with semen collection (9, 20). Epidural lidocaine, intravenous xylazine, or intrarectal topical application of lidocaine did not significantly decrease the discomfort, cortisol concentrations, or heart rate of bulls during electroejaculation (8,14,21).
  9. Some studies have shown that the electrical stimulation required to induce ejaculation and the potential discomfort from it can be reduced by administration of oxytocin, carbetocin (an oxytocin analogue) (22), a prostaglandin F2alpha analogue, or by transrectal massage of the accessory sex glands prior to electroejaculation (15-24). When collecting semen for storage purposes in rams, carbetocin pre-treatment could result in fewer collections by improving the quality and quantity of ejaculate obtained (22). Pre-treating rams with GnRH prior to electroejaculation decreased cortisol, whereas oxytocin and prostaglandin F2alpha analogues decreased stress responses, but had no effect on time or number of pulses (26). Fasting bulls 24 h pre-collection reduced bladder size and increased the proportion of bulls with penis protrusion, erection and ejaculation, but did not reduce the number of stimulations or discomfort (27). Species differences, withdrawal times, field conditions, the time to onset of action, duration of action, risk of ataxia and sedation should all be considered when administering drugs prior to electroejaculation. There continues to be a need for more research focused on novel analgesics, hormones and other tools applicable in field conditions that could reduce discomfort during electroejaculation (28-32).
  10. Veterinary medicine is provincially regulated. Veterinarians, livestock producers and members of the public should consult their relevant provincial veterinary regulatory authority to determine who is permitted by regulation to perform electroejaculation in their jurisdiction and to determine how each provincial/territorial regulator defines veterinary supervision. In all situations, veterinary supervision is indicated.

References

  1. 1. Hopper RM, King EH. Evaluation of breeding soundness: Basic examination of the semen. Bovine Reproduction. Ames, Iowa, USA: John Wiley & Sons, Inc 2014:68-78. Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119602484.ch9 Last accessed Augsut 19, 2024.
  2. Abril-Sánchez A, Freitas-de-Melo A, Giriboni J, Santiago-Moreno J, Ungerfeld R. Sperm collection by electroejaculation in small ruminants: A review on welfare problems and alternative techniques. Anim Reprod Sci 2019;205:1-9.https://www.sciencedirect.com/science/article/abs/pii/S0378432019300648 Last accessed August 19, 2024.
  3. Bopape M, Lehloenya K, Chokoe T, Nedambale, T. Comparison of electro ejaculator and artificial vagina on semen collection from South African indigenous goat following assessment by computer aided sperm analysis. Open J Anim Sci 2015;5:210-218. Available from: https://file.scirp.org/Html/15-1400324_55970.htm. Last accessed August 19, 2024.
  4. Palmer CW. Welfare aspects of theriogenology: Investigating alternatives to electroejaculation of bulls. Theriogenology 2005;64:469-479. Available from: https://www.ncbi.nlm.nih.gov/pubmed/15955553 Last accessed August 19, 2024.
  5. NFACC 2013 Code of Practice for the Care and Handling of Sheep. Available from: https://www.nfacc.ca/codes-of-practice/sheep Last accessed August 19. 2024.
  6. NFACC 2022 Code of Practice for the Care and Handling of Goats. https://www.nfacc.ca/goats-code-of-practice Last accessed August 19, 2024.
  7. Stafford KJ, Spoorenberg J, West DM, Vermunt JJ, Petrie N, Lawoko CRO. The effect of electro-ejaculation on aversive behaviour and plasma cortisol concentration in rams. N Z Vet J 1996;44:95-98. https://www.ncbi.nlm.nih.gov/pubmed/16031903 Last accessed September 11, 2018.
  8. Orihuela A, Aguirre V, Hernandez C, Flores-Perez I, Vazquez R. Breaking down the effect of electro-ejaculation on the serum cortisol response, heart and respiratory rates in hair sheep (Ovis aries). J Anim Vet Adv 2009;8:1968- 1972. https://www.researchgate.net/publication/281228386_Breaking_down_the_Effect_of_Electro-Ejaculation_on_the_Serum_Cortisol_Response_Heart_and_Respiratory_Rates_in_Hair_Sheep_Ovis_aries. Last accessed August 19, 2024.
  9. Falk AJ, Waldner CL, Cotter BS, Gudmundson J, Barth AD. Effects of epidural lidocaine anesthesia on bulls during electroejaculation. Can Vet J 2001;42:116-120. https://pubmed.ncbi.nlm.nih.gov/11272454/ Last accessed August 19, 2024.
  10. Damián JP, Ungerfeld R. The stress response of frequently electroejaculated rams to electroejaculation: Hormonal, physiological, biochemical, haematological and behavioural parameters. Reprod Domest Anim 2011;46:646-650 Last accessed August 19, 2024.
  11. Whitlock BK, Coffman EA, Coetzee JF, Daniel JA. Electroejaculation increased vocalization and plasma concentrations of cortisol and progesterone, but not substance P, in beef bulls. Theriogenology 2012;78:737- 746. https://www.ncbi.nlm.nih.gov/pubmed/22537995 Last accessed August 19, 2024.
  12. Abril-Sánchez S, Freitas-de-Melo A, Damián JP, Giriboni J, Villagrá-García A, Ungerfeld R. Ejaculation does not contribute to the stress response to electroejaculation in sheep. Reprod Domest Anim 2017;52:403- 408. https://www.ncbi.nlm.nih.gov/pubmed/28120512 Last accessed August 19, 2024.
  13. Etson CJ, Waldner CL, Barth AD. Evaluation of a segmented rectal probe and caudal epidural anesthesia for electroejaculation of bulls. Can Vet J 2004;45:235-240. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC548610/ Last accessed August 19, 2024.
  14. Mosure WL, Meyer RA, Gudmundson J, Barth AD. Evaluation of possible methods to reduce pain associated with electroejaculation in bulls. Can Vet J 1998;39:504-506. Available from: https://www.ncbi.nlm.nih.gov/pubmed/9711391 Last accessed August 19, 2024.
  15. Abril-Sánchez S, Freitas-de-Melo A, Beracochea F, et al. Sperm collection by transrectal ultrasound-guided massage of the accessory sex glands is less stressful than electroejaculation without altering sperm characteristics in conscious goat bucks. Theriogenology 2017;98:82-87. Available from: https://www.sciencedirect.com/science/article/pii/S0093691X1730225X Last accessed August 19, 2024.
  16. Ungerfeld R, Pinto-Santini L, Chaumont S, Orihuela JC, Guerrero-Gutierrez M, Freitas-de- Melo A. Is the ram that is more receptive to brushing, less reactive to electroejaculation? Livest Sci 2021:254:104764 https://www.sciencedirect.com/science/article/abs/pii/S1871141321003723 Last accessed August 19, 2024.
  17. Bopape M, Lehloenya K, Chokoe T, Nedambale, T. Comparison of electro ejaculator and artificial vagina on semen collection from South African indigenous goat following assessment by computer aided sperm analysis. Open J Anim Sci 2015;5:210-218. https://file.scirp.org/Html/15-1400324_55970.htm Last accessed August 19, 2024.
  18. Abril-Sánchez S, Freitas-de-Melo A, Giriboni J, Santiago-Moreno J, Ungerfeld R. Sperm collection by electroejaculation in small ruminants: A review on welfare problems and alternative techniques. Anim Reprod Sci 2019;205:1-9. https://pubmed.ncbi.nlm.nih.gov/30962039/ Last accessed August 19, 2024.
  19. Hargreaves AL, Hutson GD. Handling systems for sheep. Livest Prod Sci 1997;49:121-138. https://www.sciencedirect.com/science/article/pii/S0301622697000092 Last accessed August 19, 2024.
  20. Pagliosa RC, Derossi R, Costa DS, Faria FJC. Efficacy of caudal epidural injection of lidocaine, xylazine and xylazine plus hyaluronidase in reducing discomfort produced by electroejaculation in bulls. J Vet Med Sci 2015;77:1339- 1345. https://www.ncbi.nlm.nih.gov/pubmed/26097016 Last accessed August 19, 2024.
  21. Etson CJ, Waldner CL, Barth AD. Evaluation of a segmented rectal probe and caudal epidural anesthesia for electroejaculation of bulls. Can Vet J 2004;45:235-240. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC548610/ Last accessed August 19, 2024.
  22. Orihuela JC, Freitas-de-Melo A, Pinto-Santini L, et al. A single administration of carbetocin before electroejaculation increases the insemination doses produced from each ejaculate in rams. Theriogenology 2024;221:1–8. https://www.sciencedirect.com/science/article/abs/pii/S0093691X24001158 Last accessed August 19, 2024.
  23. Palmer CW, Amundson SD, Brito LFC, Waldner CL, Barth AD. Use of oxytocin and cloprostenol to facilitate semen collection by electroejaculation or transrectal massage in bulls. Anim Reprod Sci 2004;80:213-223. https://www.sciencedirect.com/science/article/abs/pii/S0378432003001763 Last accessed August 19, 2024.
  24. Ungerfeld R, Casuriaga D, Giriboni J, Freitas-de-Melo A, Silveira P, Brandão FZ. Administration of cloprostenol and oxytocin before electroejaculation in goat bucks reduces the needed amount of electrical stimulation without affecting seminal quality. Theriogenology 2018;107:1-5. https://www.sciencedirect.com/science/article/abs/pii/S0093691X17305204 Last accessed August 19, 2024.
  25. Orihuela JC, Freitas-de-Melo A, Pinto-Santini L, et al. A single administration of carbetocin before electroejaculation increases the insemination doses produced from each ejaculate in rams. Theriogenology 2024;221:1-8. https://pubmed.ncbi.nlm.nih.gov/38518659/ Last accessed August 19, 2024.
  26. de Moura Fernandes DA, de Souza CV, Alvarez Balaro MF, et al. Response of rams to electroejaculation following the administration of oxytocin and cloprostenol with or without GnRH. Theriogenology 2021;173:32-36 https://pubmed.ncbi.nlm.nih.gov/34265698/ Last accessed August 19, 2024.
  27. Romano JE, Mari G, Stradaioli G, Mislei B. Effect of fasting prior to electroejaculation on behavioral responses and reproductive parameters in young Simmental bulls. Theriogenology 173;2021:19-22. https://pubmed.ncbi.nlm.nih.gov/34144273/ Last accessed August 19, 2024.
  28. Ungerfeld R, de Moura Fernandes DA, Alvarez Balaro MF, et al. Administration of butorphanol with ketamine/xylazine sedation reduces the negative responses to electroejaculation in rams. Theriogenology 2022:191:96-101. https://pubmed.ncbi.nlm.nih.gov/35973260/ Last accessed August 19, 2024.
  29. Abril-Sánchez S, Crosignani N, Freitas-de-Melo A, et al. Sedation or anaesthesia decrease the stress response to electroejaculation and improve the quality of the collected semen in goat bucks. Animal 2018;12:2598-2608. https://pubmed.ncbi.nlm.nih.gov/30451143/ Last accessed August 19, 2024.
  30. da Silva MKF, de Almeida Gélio L, Oba E, et al. Evaluation of pharmacological alternatives to reduce the pain and discomfort produced by electroejaculation in rams. Reprod Domest Anim 2024;59:e14528. https://pubmed.ncbi.nlm.nih.gov/38268202/ Last accessed August 19, 2024.
  31. Orihuela JC, Pinto‑Santini L, Beracochea F, et al. Time of day modified the time required for semen collection with electroejaculation and slightly affected the quality of fresh semen in rams. Trop Anim Health Prod 2023;55:144. https://pubmed.ncbi.nlm.nih.gov/37017826/ Last accessed August 19, 2024.
  32. Ungerfeld R, Viera MN, Freitas-de-Melo A, Giriboni K, Casuriaga D, Silveira P. Seasonality of the stress response in goat bucks when there is use of electroejaculation for semen collection. Anim Reprod Sci 2012;226:106719. https://pubmed.ncbi.nlm.nih.gov/33592529/ Last accessed August 19, 2024.