Because a ewe's cervix is longer and more complicated, artificial insemination is often performed laparoscopically. With laparoscopic AI, the semen is deposited directly into the uternine horn, by passing the cervix.
Laparoscopic insemination involves a single fixed time insemination, so it is dependant on the effectiveness of oestrus synchronisation.
Oestrus synchronisation is achieved by placing Cidrs or progesterone treated sponges in the vagina of the ewe and leaving them there for 13 – 14 days. On Cidrs/ sponge withdrawal, the ewes are injected with hormone to tighten the time of ovulation
Ewes have to be starved for at least 12 hours before AI to reduce the content of the rumen and the bladder. The abdomen is prepared by shearing, shaving and disinfecting. The trocars and cannulae are inserted 7 – 10 cm ventral to the udder and 5 – 10 cm on each side of the mid-ventral line.
A scalpel blade can be used to make a small incision in the skin to facilitate penetration. The 7 mm trocar and cannula that is connected with the CO2 is first introduced and the abdomen is slightly inflated to create space in the abdomen and to reduce the chance of injury to organs.
Insertions of the first trocar and cannula should be well controlled and the sharp trocar is withdrawn as soon as the abdominal wall has been pierced. The blunt cannula is pushed well into the abdomen and the second trocar and cannula is inserted, for increased safety, after inflation with CO2. Endoscope and AI instrument go through the cannulae and the uterus is located just ventral to the bladder. Semen is deposited in each uterine horn approximately halfway between the uterine bifurcation and the utero-tubal junction. A light stab action of the aspic and the turn of the plunger deposit about 0,1 ml of diluted or frozen thawed semen into the lumen of each uterine horn (total 0,2 ml). Instruments are withdrawn and put into disinfectants between each animal. An antibiotic spray is applied to the 2 wounds.
Laparoscopic insemination with fresh or frozen semen has become an essential and integral part of controlled breeding of sheep and goats and provides valuable practical opportunities to improve reproduction efficiency and to enhance genetic improvement.