Practical 1: Artificial Insemination
BVSc & AH IV
? Ensure proper collection of semen
? Ensure proper handling and storage of the semen
? Accurate identification of animals on heat
? Ensure proper insemination procedure is followed
? Artificial vagina/ electro-ejaculator apparatuses
? Eosin B
? Liquid Nitrogen tank
? AI straws
? Semen tweezers
? Thawing unit
? Insemination gun
? Cover sheath
? Paper towels
? Rectal gloves
Collection of Semen
I. Artificial Vagina- One end allows entrance of the penis while the other end is attached to a test tube or beaker to collect the semen.
II. Electric Stimulation- The electro- ejaculator apparatus uses an electrode to pass a weak current to the sacral and pelvic nerves. The electrode is inserted in the rectum until semen is collected. This method is mainly used in bulls with leg injuries.
Figure 1: Semen collection in different animals
Evaluation of Semen
I. Motility- A drop of semen is put on a slide, covered and viewed under high magnification. Sperm must show forward, progressive movement.
II. Sperm count- Semen is diluted and the sperm are counted using a haemocytometer.
III. Live: dead ratio and morphology- A smear of the semen is made on a slide and stained using eosin B. Once stained, the slide is viewed under a microscope, making note of the number of dead: live sperm and their morphology.
Figure 2: Semen Evaluation
Storage of Semen
I. The semen is first diluted to ensure that it is used efficiently.
II. If it is to be used within two hours, the semen may be kept at room temperature.
III. For long term storage, the semen must be stored at temperatures below zero.
I. The female must be on standing heat before being inseminated.
II. Prior to insemination, the identity of the sire is checked and the semen is thawed.
III. The straw is then put in an insemination catheter and covered with a plastic sheath.
IV. In cattle, the left hand is inserted into the rectum to guide the catheter as it is inserted into the vagina. The semen is deposited in the middle of the cervix and the uterine body.
V. In sheep and goats, semen is injected from a syringe through a pipette into upper one-third of uterine horn through abdominal wall.
VI. In pigs, the method developed by Rowson and Melrose and O’Hagen is used for insemination. A spiral rubber catheter is passed into the cervix and rotated until the spiral grooves get locked in the cervical canal. A large volume of semen is then inseminated.
VII. In horses, semen is deposited in the caudal portion of the uterus. This is done using a catheter that is passed through vagina and guided by the index finger.
VIII. In dogs, the semen is deposited close to the external os of the cervix using an insemination catheter and a speculum to locate the site.
IX. In cats, artificial insemination is mostly done in wild endangered species and rare in domestic cats. Intravaginal and intrauterine methods may be used.
Figure 3: Insemination in Various Animals
Parkinson, T. (2009) Artificial Insemination. Veterinary Reproduction and Obstetrics. 9th edn. London: Elsevier Limited.