Artificial Vagina (AV) for Semen Collection in Bulls

The artificial vagina (AV) method of semen collection in bulls has replaced older, cumbersome, and unreliable procedures. It is considered the most satisfactory method for collecting semen from bulls.

The Artificial Vagina (AV) is a device designed to simulate the natural conditions of a cow’s vagina in order to safely and effectively collect semen from bulls during ejaculation. It is the most commonly used and reliable method for semen collection in artificial insemination programs.

History and Type of Artificial Vagina

• Russians (Kumorov and Nagev, 1932) designed the first artificial vagina. Various workers made different types of AV.
• The Cornell University workers developed Cornell Model and in US “Danish model” was developed.
• In tropical countries the “short model” was developed

Parts of Artificial Vagina

• Rubber cylinder
• Inner liner
• Director cone
• Collection vial
• Insulation bag

Preparation of Artificial Vagina

The parts AV should be sterilized before its used for semen collection to avoid the contamination and disease transmission After sterilization all parts should be dried and stored in a dust free cabinet or incubator.

The inner liner should be inserted into the AV and both the ends are turned back over the ends of the cylinder.

Rubber bands may be attached on both the ends so as to form a jacket between the liner and rubber cylinder.

The director cone is fastened over one end of the AV and the glass semen collecting vial is attached to the smaller end of the cone.

After assembling AV, half the jacket is filled with warm water of about 65-70:C is poured to get the final temperature of 42.5 to 45°C inside the AV. The remaining half of the jacket is filled with air. The temperature of AV may vary depending upon the season, time semen collection and air temperature.

The insulation bag is used in colder or hotter environment to avoid cold/heat shock to the spermatozoa. The insulation bag is applied to cover the director cone and collection vial.

After assembling the AV, sterile lubricating jelly is applied for 3 to 5 inches of the interior of liner.

Excessive lubrication will cause the contamination over semen samples by carrying the jelly through the AV over the bull’s pelvis.

Lubricants may be used during semen collection by artificial vagina:

• K.Y. Jelly
• Sterile white Vaseline jelly
• White mineral oil
• Tragacanth gum (3 gm Tragacanth, 5 ml glycerine and 50 ml distilled water)

Preparation of Bull

Semen collection is done in the early morning. The animals will be active and the stomach will be empty in the morning hours which help in better semen collection.

The scheduled bulls will be carried from their paddocks to washing area. The animals should be washed to remove all the dirt. They should be tied surrounding the collection shed and should be dried.

The bulls should be tied with bull apron and the prepuce should be cleaned with normal saline

The bulls are allowed to watch the other bulls mounting which will stimulate the bull. The forward and backward movement of dummy will also stimulate the bull.

The protrusion of penis from prepuce will indicate the bull is ready to mount.

Procedure of Semen Collection

The teaser bull should be restrained in a chute. The bull is allowed form behind the teaser and 2 to 3 false mountings are given.

The right handed operator can approach the bull from right side by holding the AV on his right hand.

When the bull mounts and ready to make the thrust, the operator using the left hand drawn the penis from sheath and directs it into the AV which is held at an angle that it is in have with the testis.

During the entire process the testis itself should not be touched as it will leads to refusal to service.

The AV should be directed in such a way that the semen should be ejaculated in director cone or directly on collection vial.

On completion of the thrust the collection tube is immediately doubled back on the cone so as to exclude any semen that might has been deposited on testis should not enter inside the collection vial (as it carries bacteria from penis and sometimes lubricating jelly).

After collecting the semen the collection vial is disconnected immediately, closed with clean stopper/sterile aluminium, plastered with details of bulls, placed in a beaker containing water of about 34°C and examined as soon as possible.

Hygiene and Precautions at Collection

The bull and the location of semen collection should be clean, dry and free from dust and mud. Collection yard should not be overcrowded with bulls and new persons.

The semen collector should wear protective clothing and gum boots. The hind portion of the dummy should be as clean as possible.

During collection the penis should be prevented from coming in contact with the dummies hind quarter. For this the bull apron can be used.

The preputial hairs should be clipped at regular interval and the prepuce should be washed with normal saline weekly twice.

More than two ejaculates cannot be collected from a bull in one day. Don’t grasp the unsheathed penis at the time of collection.

The semen collector should not enter into the lab. The semen should be given through the pass box.