Artificial Insemination

Reasons to do AI and methods of mating

One basic drive force namely: Better usage of the ram or buck.

Compare the following Mating Systems

  • Group Mating: 3% Rams with ewes for a period of 6 weeks. 30-40 ewes/ram/season.
  • Hand mating: Ewes in oestrus brought to the ram. Ram mates 5 ewes twice a week.
  • AI with fresh semen: Semen collected on the farm. 10 Ewes inseminated with one ejaculate. On average 40 ewes/ram/day.
  • Laparoscopic intrauterine AI with fresh or frozen semen: Only 20 million live sperm needed for fertilization. Up to 100 ewes/day/ram with fresh semen. With frozen semen in storage an experienced operator with good assistance can inseminate up to 300 ewes/day. There are two ways of artificial insemination namely: cervical insemination and laparoscopic insemination.

CERIVICAL INSEMINATION – Cervical insemination with fresh semen

Basic equipment consists of a speculum with a build in light source and a pipette connected to a 1ml syringe. The plastic disposable pipettes are popular. For sheep the tip is tapered over a flame and bent at about 30%. For goats penetration of the cervix is easier with a straight pipette. Restraint of animals by putting the elevated hindquarters over a rail with the head downwards. Height of the rail should be 80-90cm and the front legs should remain standing on the floor of the race. One assistant to stand over ewe and secure the hind legs.The vulva of the ewe is wiped with cotton wool or a tissue. The speculum with a bit of lubrication is carefully inserted into the vagina to a depth of 10-13cm. The cervix opening is identified and located. A large variation in size and shape of cervix opening between females. In maiden ewes it is sometimes observed just as a split in the anterior vagina, whilst in older ewes the cervix usually protrudes into the vagina and the opening of the cervix has to be find with the bend tip of the pipette between the folds of the cervix.

An assistant loads the inseminating pipette. The plunger of the syringe is withdrawn to 0,2ml to have some air behind the semen. The appropriate amount of semen is drawn into the pipette from the semen collection tube in a water bath at 30 °C-34°C. The pipette is kept warm by quaze swab. The inseminator should attempt to introduce the pipette into the cervix without using force. Semen is deposited into the cervix by depressing the plunger of the syringe. The speculum is withdrawn first and then the pipette to prevent backflow of the semen. In sheep deposition of semen deeper than 1cm into the cervix canal is seldom possible. In goats it is easier to achieve deep penetration or even intrauterine insemination. Complete penetration can be felt by the lack of resistance. Avoid pushing the pipette by force too deep as this can cause damage to the cervix canal.

When large amounts of mucus has accumulated in the vagina or when mucus covers the cervix, the vagina should be drained. The assistant lifts the front end of the ewe up high and the mucus drains through the speculum tube. Instruments must be cleaned between inseminations. Speculum is wiped off between each ewe. Pure alcohol is also used regularly to clean and disinfect instruments. Mild disinfectants can be used to rinse the speculum. Rinse again in clean water as disinfectants are detrimental to semen.AI Pipettes should be wiped with a quaze swap between ewes.

Diluent for fresh semen at 30°C -34°C – Skim milk

Sterilised cow skim milk or UHT skim milk (long life milk) is the most convenient diluent to use on farms. Conception depend on number of mobile spermatozoa and not on volume. Diluent used to extend life span of semen for 1-2 hours and to have a slighter higher volume for easier AI. Semen with density of cream to thick cream and motility of 5 and 4 can be diluted 1+2 to 1+3. Insemination dose 0,1ml-0,2ml/ewe. Thin cream semen with motility of 3 / 4 – diluted only 1+1.

Transport of Fresh Semen

Fresh semen diluted with a special diluent, can be cooled down to 15 °C or to 5°C and kept for 4 –12 hours before AI. Acetic acid frozen-thawed ampulles (IMV-France) is a practical and easy method to transport semen at 15°C-17°C in a small thermos flask – 3 ampulles needed per flask. Semen last longer at lower temperatures and can be transported at 5°C in small electronic freezers which operate on 12 V electric supply. Tubes with cooled semen packed in water and ice in a thermos flask or insulated container is practical as well. Add ice during the trip to maintain the temperature at 5°C. Semen tubes protected with cotton wool against direct contact with ice.

Laparoscopic Insemination

Please contact Hendriette Stafford at