Electroejaculation of bulls, rams, and bucks

This is an updated policy which merges and replaces two previous policies: Electroejaculation of rams (2013) and Collection of semen from animals by electroejaculation (2008).

Policy

1. To ensure the welfare of bulls, rams and bucks undergoing electroejaculation, the procedure must only be conducted by, or under the direct supervision[1] of, an appropriately experienced veterinarian.
2. Appropriate veterinary knowledge, extensive practical training and clinical experience with the procedure is required to safely and effectively electro-ejaculate bulls, rams, and bucks.
3. Safety of the animal and the veterinarian/operator is essential. Requirements include appropriate and well-maintained equipment suited to the species and the size of the animal, and knowledge of the circumstances under which sedation may be required.
4. If the procedure fails to produce an ejaculate within a reasonable length of time, its use must be reassessed.
5. In some species, general anaesthesia or sedation may be indicated.

Background

Benefits of electroejaculation

Reproductive assessment of bulls, rams, and bucks is vital for the optimal health, welfare and production management of herds and flocks. Electroejaculation is used for the safe collection of a sample of semen from bulls, rams and bucks. Semen is collected for the purpose of assessing fertility, investigating infertility, artificial insemination, and semen preservation. This procedure also enables visual assessment of the penis and prepuce.

The semen collected may yield information important to their reproductive disease status and welfare. Mating sub-fertile bulls, rams, and bucks results in a longer, often sub-optimally timed birthing period, which can adversely affect survival and subsequent productivity of both breeding females and their offspring. Therefore, the benefits of electroejaculation apply not only to the males undergoing the procedure, but also subsequently across the breeding females and offspring in the herd or flock.

The collection of semen can also enable preservation of semen from males with genetically desirable health, welfare, and production traits. Subsequent use of artificial insemination can result in widespread dissemination of these traits resulting in an overall improvement in the health, welfare, and productivity of a population of cattle sheep and goats e.g., dissemination of the polled gene in the cattle population. Further, artificial insemination with semen from high health status males is an effective means of controlling the transmission of important reproductive diseases.

Animal welfare considerations

Electroejaculation involves the controlled and targeted administration of low-level electrical stimuli to the nerves which control emission and ejaculation. Electroejaculation is invasive and the electrical stimulation causes an unfamiliar sensation. However, extensive research into the impact of electroejaculation on the welfare of bulls, rams and bucks has demonstrated that the procedure is no more stressful than other commonly performed tasks, such as physical restraint or vaccination (Welsh & Johnson, 1981; Stafford et al., 1996). In rams, the behavioural and cortisol response to EEJ was similar to those caused by shearing or lateral restraint (Stafford et al., 1996). In bulls, insertion of the probe has been observed to be comparable to rectal palpation, an accepted and common procedure in cattle practice (McGowan & Mueller, 2004). Serum cortisol concentrations were less elevated following use of EEJ compared with physical restraint or rectal palpation (Welsh & Johnson, 1981).

In order to investigate stress associated with the procedure in bulls, cortisol was measured by Falk et al., (2001). There was a mild increase in cortisol during and shortly after the procedure, but this rapidly returned to normal. A similar response was observed in bucks (Oritz-de-Montellano et al., 2007). It is noted that Borg et al. (1991) identified a rise in cortisol following ejaculation from natural mating.

Additionally, Welsh & Johnson (1981) and Mosure et al., (1998) found there was no aversion to re-entering the handling facilities after repeated electroejaculation procedures, indicating that the discomfort due to electroejaculation in bulls is mild (Palmer, 2005). Chenoweth & Sanderson (2001) conclude that electroejaculation is a highly effective and safe semen collection method for both animal and veterinarian.

A suitable ejaculate is usually obtained with less than five minutes of stimulation, and the whole procedure, including preparation of the bull, ram or buck, usually requires no more than ten minutes of restraint (BULLCHECK® Veterinary Bull Breeding Soundness Evaluation 4^th Edition). The findings of experienced veterinarians are that in an extremely high proportion (>95%) of bulls and rams, a representative sample of semen suitable for microscopic assessment can be collected by electroejaculation.

Inappropriate use of the procedure by unskilled persons may cause significant stress and trauma to animals. Veterinarians require extensive practical training and experience to be able to consistently conduct electroejaculation without adversely affecting the animal’s welfare. It is important that the operator uses techniques to minimise stress responses during the procedure. In particular, as there is some variation in the degree of response of bulls, rams, and bucks to electroejaculation (Cameron, 1977); it is critical that the veterinarian promptly recognises the signs of excessive response to stimulation and is aware of the different approaches that can be used to best manage these cases (McGowan et al., 2004).

Purpose

This document provides guidelines on the electroejaculation of bulls, rams and bucks for members, and an explanation of AVA’s policy on this procedure.

References

Beggs D, Bertram J, Chenoweth P, Entwistle K, Fordyce G, Johnston H, Johnston P, McGowan M, Niethe G, Norman S and Perry V (2013). Veterinary bull breeding soundness evaluation. Australian Veterinary Association, Australian Cattle Veterinarians Eight Mile Plains, Queensland. (ISBN 9780980796797)

Borg KE, Esbenshade KL, and Johnson BH (1991). Cortisol, growth hormone, and testosterone concentrations during mating behavior in the bull and boar, J Anim Scie 69: 3230–3240.

BULLCHECK® Veterinary Bull Breeding Soundness Evaluation 4^th Edition.

Cameron RDA (1977). Semen collection and evaluation in the ram: The effect of method of stimulation on response to electroejaculation. Australian Veterinary Journal, 53, pp. 380–383.

Chenoweth PJ and Sanderson MW 2001. Health and Production Management in Beef Cattle Breeding Herds. Ch 13 (pp509-580) in; Herd Health: Food Animal Production Medicine, Ed. Otto M Radostits, 3 ^rd edition. WB Saunders and Co., New York. (see p 573)

Falk AJ, Waldner CL, Cotter BS, Gudmundson J and Barth AD (2001). Effects of epidural lidocaine anesthesia on bulls during electroejaculation. Can Vet J 42:116–120.

McGowan MR and Mueller, K (2004).  Guidelines for the electroejaculation of bulls in the United Kingdom.  Published by the British Cattle Veterinary Association, 11pp.

Mosure WL, Meyer RA, Gudmundson J, and Barth AD (1998). Evaluation of possible methods to reduce pain associated with electroejaculation in bulls. Can Vet J 39:504–506.

Ortiz-de-Montellano, M, Galindo-Maldonado, F, Cavazos-Arizpe, EO, Aguayo-Arceo, AM, Torres-Acosta, JFJ and Orihuela, A, 2007. Effect of electro-ejaculation on the serum cortisol response of Criollo goats (Capra hircus). Small Rumin Res, 69:228-231.

Palmer CW (2005). Welfare aspects of theriogenology: Investigation alternatives to electroejaculation of bulls. Theriogenology 64: 469-479.

Stafford, KJ, Spoorenberg, J, West, DM, Vermunt, JJ, Petrie, N and Lawoko, CRO, 1996. The effect of electro-ejaculation on aversive behaviour and plasma cortisol concentration in rams. New Zealand Veterinary Journal, 44(3), pp.95-98.

Welsh TH Jr and Johnson BH. (1981). Stress-induced alterations in secretion of corticosteroids, progesterone, luteinizing hormone, and testosterone in bulls. Endocrinology, 109(1), pp.185-190.

[1] Direct supervision means the supervising veterinarian is present and able to assist or intervene.