Reproduction – Artificial Insemination

We have many years of experience and expertise in equine reproduction.


We are lucky enough to have 4 equine vets that have a keen interest in this challenging but rewarding field of equine veterinary medicine. We are a BEVA (British Equine Veterinary Association) approved AI (Artificial Insemination) practice, with vast experience in using chilled and frozen semen. We also offer embryo transfer as a service in partnership with Millfield Stud at Settle.

We have several portable ultrasound scanners and can perform our reproductive services as an ambulatory service; mares can also be examined at our practice or at Millfield Stud.

Artificial Insemination

We recommend a pre-breeding assessment of the mare which should be performed when the mare is in season. This includes an examination of the vagina and cervix, a rectal examination, an ultrasound examination of the reproductive tract and ovaries, the collection and examination of an endometrial smear.

The use of artificial insemination reduces the risk of injury to the mare and stallion and reduces the risk of spreading venereal diseases. The biggest benefit is that the mare owner can choose from the best stallions in the world.

Mares are natural breeders and often start their cycle in April; they can breed until August/September. Mares can be made to start their cycle earlier with the use of hormones or by artificially increasing the length of daylight.

Preparation can be either at stud or home; if facilities are available. A stud is preferable to maximise chances of pregnancy and allow rectal examinations to be performed safely.

If necessary, we will stimulate the mare to come into season. We often give an injection of a hormone on Thursday/Friday and the mare will then come into season early the following week.

Once in season we ultrasonically examine her reproductive tract every 24 hours. Once there is a large enough follicle (structure on the ovary that releases the egg), a relaxed cervix and good oedema pattern in the uterus, we administer a drug to induce the follicle to release the egg (ovulation usually occurs 24-48 hours after injection).

Chilled Semen

Semen ordered for the following day and inseminated on arrival, this must be inseminated within 48 hours of collection from stallion.

Frozen Semen

Mare examined as often as every 6 hours to ensure insemination is performed as close to ovulation as possible. This must be inseminated within 12 hours prior to ovulation or 6 hours post ovulation.

The mare is examined the following day to confirm ovulation and assess if the uterus has reacted to the semen. If required, fluid treatments and/or intra uterine antibiotics may be administered.

Please see our Vet Plan page for further information and prices.

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