Electro-Ejaculation: A Method of Semen Collection in Livestock
In livestock production, semen collection is a procedure used as part of breeding soundness examination and to a lesser extent fordiagnosis of reproductive diseases or research purposes in ruminants, including rams (Stafford, 1995).There are four methods of semen collection; vaginal aspiration, use of an artificial vagina (AV),transrectal massage and electro-ejaculation(EE)(Palmer, 2005). Electro-ejaculation is a useful alternative means for obtaining semen from ruminants that have not been trained to serve into an artificial vagina. The Electro-ejaculation technique was first described by Gunn in rams in 1936. He first made extensive use of electro-ejaculation as a means of collecting semen from rams. In 1952 this technique was first adopted by Batelli for collection of semen from guinea pigs.
In the realm of livestock reproduction, the quest for efficient and humane methods of semen collection has led to the development of various techniques. One such method that has gained prominence is electro-ejaculation. This article explores the intricacies of electro-ejaculation, shedding light on its procedure, applications, and its role in advancing reproductive technologies in livestock. Electro-ejaculation (EE)is a useful means for obtaining semen from livestock. By this method, collection of semen is carried out by inserting a probe or electrode in sire’s rectum and stimulating nerves of the reproductive system by gradually increasing voltage in episodes for a short period of time. A successful electro-ejaculation requires skill, experience, patience and the knowledge of individual requirement of the stimulation.
Understanding Electro-Ejaculation:
- Principle:
- Electrical Stimulation: Electro-ejaculation involves the use of a rectal probe equipped with electrodes that deliver controlled electrical stimuli to the pelvic nerves.
- Muscular Contractions: The electrical stimulation induces rhythmic muscular contractions in the reproductive tract, facilitating semen expulsion.
- Applicability:
- Species Diversity: Electro-ejaculation is adaptable across various livestock species, including cattle, sheep, goats, and deer.
- Assistance in Reproductive Research: Widely employed in research settings, electro-ejaculation aids in the study of reproductive physiology and the development of assisted reproductive technologies.
Equipment’s for electro-ejaculation method —The equipment used for the procedure includes rectal probes of variable sizes (Table 1), an electrical current generator, collection tube (attached to a latex rubber cone) and semen collection handle (Figure 1). At present there are a number of electro-ejaculators in the market of the world, which are either operated only on battery, or battery-cumelectric transistorized circuits. Modern models of electro-ejaculators consists of a single rectal probe equipped with bipolar electrodes capable of producing ejaculation by electrical stimuli of the vesicular glands, ampulae of the vas deferentia, accessory sex glands, and the hypogastric plexus.
Diameter of rectal probe using in electro-ejaculation in different species
Animals —–Diameter
Bull 65mm-75mm
Older bulls 90mm
Ram 35 mm
The Electro-Ejaculation Procedure:
- Restraint and Preparation:
- Physical Restraint: Safely securing the animal to ensure minimal stress during the procedure.
- Probe Lubrication: Application of a suitable lubricant on the rectal probe to ease insertion.
- Electrode Placement:
- Precise Placement: Insertion of the rectal probe with electrodes positioned strategically to stimulate the pelvic nerves.
- Controlled Settings: The electrical stimulus is administered in controlled sequences and intensity.
- Semen Collection:
- Rhythmic Contractions: Electrical stimulation induces rhythmic contractions of the accessory sex glands, leading to the expulsion of semen.
- Collection Receptacle: Semen is collected in a suitable receptacle for subsequent evaluation and processing.
- Post-Procedure Care:
- Recovery: Ensuring the well-being of the animal post-procedure, including monitoring for any signs of stress or discomfort.
- Observation: Veterinarians or trained personnel observe and document the quality and quantity of collected semen.
Animals in which it is used —-Electro-ejaculation is a very efficient procedure for obtaining semen from wild and domestic animals. Moreover, this procedure is easy, safe to apply, improves reliability in obtaining sample and requires minimal facilities (Palmer, 2005).Electro-ejaculation is anextensively and successive used method for semen collection in some species like bovine and ovine. Electro-ejaculation use in stallions is not advisable because of the risks for both the animal and operator (Stover et al., 1981).
Management during semen collection: Preparation of animals before semen collection: Before collection of semen, the bull is directed into a travis and left to rest for 2 to 3 min. Hairs around the prepuce is clipped and then cleaned with an antiseptic solution (no soaps or detergents should be added to the water as most are spermicidal) followed by wash with tap water and dried. The bull‘s accessory sex organs should be examined per rectum. Collection Procedure: Restrain the animal and empty the rectum by using warm saline. The probe is slightly lubricated with some non-insulating material. Pass the probe into the rectum (Bull: 12 inches, Ram: 6-8 inches) and held in a position of rectal floor. Pass the required electrical current through electrical current generator . Hold the penis with gauze and direct the urethral process into the collection vial to collect the semen.The current produced by the probes and electro-ejaculation is stimulated by starting with the probe set at the lowest voltage and gradually increasing the voltage until ejaculation occurs.
Required electrical stimulus in different species
Animal ————Bull ——————Ram
Voltage (volts) 10-15 ———-10-15
Current (amp) 0.5 -1 –
Time (sec) 5-10—— 3-5
Intervals (sec) 15-20 ——5-15
Stimulus (times) 3-5—– 3-5
How does electro-ejaculation work?
Electro-ejaculation works on the principle of muscle contraction. When an electric probe is inserted into the rectum it gain contact with the intra-pelvic area. After passing of weak AC to sacral and pelvic nerves through electrodes stimulates the smooth muscles of the ampulla and vas deferens thus inducing the ejaculatory response.
Response during electro-ejaculation: Electro-ejaculation (EE) is widely used method of semen collection in animals, which produces a stress response with negative effects on animal welfare. Response during EE can be observed through pain and stress hormone concentration. Understanding of pain in animals is very difficult (Palmer, 2005). However, it can be observed through their action i.e. struggling, muscle spasms and vocalization. In rare cases the animal may lie down or become recumbent. Various studies have been conducted to assess pain response during electro-ejaculation, with and without the use of anaesthesia and analgesia. Pain during electro-ejaculation may be subjective to operator technique hence operators must attempt to apply electrical stimulation as gently as possible. The concentration of cortisol increased and testosterone decreased after electro-ejaculation. It is noticed that heart and respiratory rate increased 10 min after electro-ejaculation (Damian and Ungerfeld, 2011). Vocalization is considered more useful in measuring pain response than either heart rate or cortisol.
Characteristics of semen —–Characteristics of semenvary with the method of semen collection. According to the study of Malejaneet al. (2014) on sheep, AV method yielded significantly better quality semen than EE and concluded EE to be the less reliable method than AV, however some researchers (Palmer et al., 2005) found EE as good method of semen collection than rectal massage. Volume:Different method of collection influences volume of semen and sperm concentration (Austin,1962 and Jimenez-Rabadan, 2012). Marco-Jimenez (2008) found that sperm concentration was lower and volume was higher in the semen collected from EE method as compared to semen collected by AV method; however Matthews et al. (2003) found no difference in the volume of semen collected by AV and EE method. Also, Palmer et al. (2005) found lower semen concentration inrectal massage method of semen collection than EE. pH: The study of Malejaneet al. (2014) showed that semen pH doesn’t vary between the two method of collection i.e. AV and EE techniques. Colour:The colour score between the AV and EE semen collection techniques varies andis due to the variation in the concentration of semen (Malejaneet al., 2014). Sperm motility: AV method showed higher sperm motility as compare to EE technique of semen collection (Malejaneet al., 2014 and Austin, 1962). Sperm wave motion also varies between the two methods of semen collection (Malejaneet al., 2014). Palmer et al. (2005) observed lower percentage of motile sperm in rectal massagemethod as compare to electro-ejaculation. Abnormality of sperm:As per the study ofMalejaneet al.(2014)sperm abnormalities do not vary between the different methods of semen collection. Sperm viability or percentage live sperm:According to Jimenez-Rabadan (2012) semen collected from AV has more percentage of intact spermatozoa than electroejaculation method.However, Malejaneet al. (2014) found no difference in the percentage of live spermatozoa between the AV and EE method of semen collection.
Advantages of Electro-Ejaculation:
1. Electro-ejaculation can be used satisfactorily for breeding soundness examination purposes. 2. No female or dummy is required. 3. It can be applied in the field using a battery powered unit. 4. It can be used to obtain semen from animals that are physically incapable of mounting due to musculo-skeletal disease or injury. 5. There are less chances of contamination. 6. In this method of semen collection no training of the male is required. 7. Semen is free of extraneous secretions. 8. A sterile condition of the apparatus ensures disease control. 9. The viability of the sperm is better.
Non-Invasive Technique:
- No Surgical Intervention: Electro-ejaculation eliminates the need for surgical procedures, reducing associated risks and complications.
- Minimized Stress: Compared to other methods, it minimizes stress on the animal during semen collection.
Standardized Semen Collection:
- Consistent Results: The controlled nature of electrical stimulation allows for consistent and repeatable semen collection.
- Research Applications: Ideal for research studies requiring standardized semen samples for experimentation.
Versatility:
- Multiple Species: Electro-ejaculation’s adaptability to diverse livestock species enhances its versatility.
- Research Exploration: Enables researchers to explore reproductive aspects across different animals.
Disadvantages of electro-ejaculation: 1. It is highly technical method, needs skill and practice. 2. Urine may be mixed with semen. 3. Avoid contamination of the semen from water, lubricating jelly or other harmful substances. 4. Animal may lie down due to paralysis of the leg, so harmful. 5. Semen volume is larger and concentration is lower of that collected by AV. 6. Some males resist too much and refuse collection.
Considerations and Ethical Practices:
Professional Expertise:
- Veterinary Supervision: Electro-ejaculation should be performed under the supervision of experienced veterinarians or trained professionals.
- Animal Welfare: Prioritizing the welfare of the animal by ensuring minimal stress and discomfort.
Regulatory Compliance:
- Adherence to Regulations: Compliance with ethical and legal standards governing animal research and reproductive technologies.
- Informed Consent: When applicable, obtaining informed consent and permissions for research involving electro-ejaculation.
Continuous Advancements:
- Technological Updates: Embracing technological advancements to refine and improve electro-ejaculation procedures.
- Ethical Oversight: Continuous evaluation and ethical oversight to align with evolving standards and practices.
Conclusion:
Electro-ejaculation stands as a pivotal method in the realm of livestock reproductive technologies, providing a non-invasive and versatile approach to semen collection. As advancements continue and ethical considerations guide its practice, electro-ejaculation contributes not only to research endeavors but also to the ongoing efforts to enhance breeding programs, genetic conservation, and the overall success of livestock reproduction. Through careful implementation and ongoing refinement, electro-ejaculation emerges as a valuable tool in the hands of veterinarians, researchers, and livestock breeders dedicated to advancing the science and art of animal reproduction.
Electro-ejaculation is more practical as it does not require previous training of the animals and can be used for breeding soundness examination however it requires skilled person to do so. Though quality is not up to the level as in artificial vaginal collection method, electro-ejaculation method can be used as an alternative means of semen collection.
Compiled & Shared by- This paper is a compilation of groupwork provided by the
Team, LITD (Livestock Institute of Training & Development)
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