Semen Collection - Anatomy & Physiology

Artificial Vagina

Introduction

• Simulates the vaginal conditions of a female in oestrus.
• Generally consist of
  • Outer casing of reinforced rubber
  • Rubber liner that can be lubricated
• Temperature and pressure are controlled by water placed between the casing and liner.
• One end is attached to a funnel-like cone that is attached to a collection vessel, usually a non-breakable test tube.

• The desgin of the artificial vagina should accomplish the following:
  • Provide a suitable environment for stimulation of the glans penis.
  • Provide an environment that prevents damage to the penis.
  • Provide an environment that maximizes sperm recovery and minimizes sperm insult.

Advantages and Disadvantages of Using a Surrogate Stimulus

• Males need training to mount a surrogate animal or 'dummy'.

• Advantages of a surrogate animal:
  • Ease of cleaning
  • Minimizes risk of injury
  • Minimizes risk of disease transmission
  • Surrogate animals do not require feed input, housing or labour for maintenance.
  • Size can be easily adjusted to accommodate various males.
  • Can be mobile, so location can be changed with ease. This avoids changing location of the male - which is more dangerous, especially with Bulls.

• Disadvantages of a surrogate animal:
  • Changing the location of teasers is difficult.
  • Requires previous training of the male

Species Differences

• Stallion:
  • Leather outer casing equiped with a port to drain water.
  • Collection vessel and protective covering
  • Ideally, ejaculation takes place in a collection cone so that most semen drains directly into the collection vessel.
  • Surrogate stimulus used to collect semen from the Stallion is referred to as a 'phantom'.
    • Phantom has a biting belt to provide the stallion with a surface to bite during mounting thus providing a means for natural behaviour.
  • It is possible to palpate the urethra at the base of the penis to detect ejaculation. There may also be associated tail movements.

• Bull:
  • Black casing
  • Rubber liner
  • Collection cone and collection vessel
  • Water is placed between the casing and the liner.
  • Proper temperature critical for successful ejaculation.
  • Protective covering placed over the cone and collection vessel to prevent cold shock of the semen.

• Boar:
  • Bulb that can apply pressure to the artificial vagina.
    • High pressure is obligatory for stimulation of the glans penis and ejaculation in the boar.
  • Outer casing and liner
  • Protective covering that houses the collection vessel.

• Ram and Buck:
  • Rubber casing with a valve through which water can be added or emptied.
  • Rubber liner and collection vessel.
  • Protective covering

Electroejaculation

• Electrical stimulation of the accessory sex glands and the pelvic urethra.
• Used in males of high genetic value that cannot physically perform mounting and ejaculation.
• Electric probe is inserted into the rectum adjacent to the prostate.
• Probe delivers a single electric current of around 15 volts under general anaesthetic.
• Simulates nearby nerves, resulting in contraction of the pelvic muscles and ejaculation.