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artificialinsemination

What is artificial insemination?

Rather than allowing a stallion to mount and mate with the mare, semen is collection from the stallion using a manual method – usually using a dummy mare and rubber artificial vagina.

The semen can then be used immediately (fresh), within 24-48 hours (chilled), or can be stored for an indefinite period for use at a later date (frozen).

At a specific period in the mare’s reproductive cycle (at the time of ovulation), the semen is infused directly into the mares uterus. The sperm then swim through the mare’s reproductive tract in search of the egg. One sperm should burrow into the egg, leading to fertilisation – the start of a normal pregnancy, which should then carry on as normal. This mimics the effect of natural covering, but without many of the inherent risks. It also allows a much greater degree of control.

Why use artificial insemination?

1. AI can help control disease. This is accomplished by preventing skin contact such as in natural covering. The most important diseases it protects against are transmission EHV & CEM. In addition antibiotics can be added to the semen at the time of insemination or collection and reduce or totally eliminate breeding the mare with any bacteria at all.
2. Using AI over natural covering decreases chances of injury. Semen is generally only collected no more than every other day in an AI program, so there is much less chance for injury. In addition semen can be collected on a phantom and a mare in heat may not even be needed. Not only does this almost eliminate injury to the mare and stallion but also it dramatically reduces the chances of injury to those staff working in the covering barn.
3. Semen can be collected from stallions with libido problems. Some stallions may not have the sexual drive to cover naturally, but can semen can be harvested using various collection techniques.
4. Semen is evaluated each time it is collected, which gives consistent measures of fertility. Natural covering may occur over and over without success where a fertility problem exists. But problems like this can be picked up as they occur when using AI.
5. AI allows insemination of a greater number of mares per ejaculate: around 10-15 mares may be inseminated from a single ejaculate. This may also help prevent stallion overuse – which can often lead to the stallion responding to breeding situations in a negative way.
6. AI allows covering of mares who may be unwilling during natural covering, or may have a foal at foot which makes natural covering dangerous to the youngster. With AI mares can be covered during foal heat, or if they are aggressive towards stallions.
7. Older stallions who cover naturally may have a very low conception rate – perhaps as low as 5-10% due to age-related decrease in fertility. Semen collection and AI can allow semen to be concentrated and manipulated in other ways which can raise fertility even in a very old stallion.
8. Mares can be inseminated at a time which will increase their chances of achieving and maintaining a pregnancy. They can be monitored and then be inseminated within hours, sometimes minutes, of ovulation, which is the best time for insemination.
9. Because of several of the factors mentioned above, when AI is performed well, the pregnancy rates achieved through it can be greater than through natural covering.

How is artificial insemination achieved?

The mare is first sedated and cleaned in preparation for insemination. She is examined by the vet, including an ultrasound scan to confirm ovulation, and that she is healthy. Semen is prepared in the laboratory, and made ready for insemination via a special “insemination gun” or via a syringe and catheter.

The catheter (or catheter section of the insemination gun) is gently inserted through the cervix of the mare into her uterus. Once fully inserted, the semen is slowly infused into the uterus, and the catheter is withdrawn. This completes the process.

Should I use artificial insemination?

Unless the stallion you wish to use to cover your mare is only available for natural covering, then we would always recommend that you use artificial insemination in your breeding programme, due to the numerous advantages it has over other methods.

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