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We are an BEVA accredited artificial insemination centre using  fresh, chilled or  frozen semen at the practice or at your stable yard.

Priors Farm is a British Equine Veterinary Association (BEVA) accredited centre for artificial insemination using fresh, chilled and frozen semen. We provide a comprehensive service for breeders from conception through pregnancy and beyond. General advice and recommendations can be sought regarding all aspects of mare and stallion venereal health including pre-breeding season disease screening, disease management and pregnant mare management.

Our reproductive services include Pre-breeding assessment of your mare, Artificial Insemination with fresh/chilled or frozen semen, Long term storage of frozen semen, Gynaecological management of mares, Pregnancy diagnosis, Infertility Investigation and treatment of barren or problem mares

The practice enjoys a range of equipment and facilities which enable the most appropriate examinations and tests to be performed in the safest environment and includes stocks to enable safe perineal examinations/procedures and a range of ultrasound scanning units giving excellent image acquisition and quality.

Traditionally, artificial insemination with frozen semen has suffered from inferior conception rates compared to fresh or chilled semen but recent research and modification of techniques used have resulted in a significant improvement in frozen semen conception rates. Certain criteria need to be considered to determine the most appropriate method of insemination for your mare such as age, parity, temperament and desired stallion availability. Your vet will be happy to discuss your mares’ requirements with you.

How your mare will be managed depends upon the type of semen to be used, please see the following section as a general guide:

Fresh/Chilled Semen

Mares can be managed at home but are often more easily managed at the practice. The semen is requested from the stud once the mare is confirmed in season and has a follicle judged to be within 24 hours of ovulation by serial internal ultrasound examinations. Timing is important as insemination should be performed within 24 hours of ovulation, in most cases a drug will be given to ensure ovulation occurs within the desired period. Semen can be delivered to your home address or the practice and is delivered in an insulated chilled. Your mare will then be inseminated and an ultrasound examination will be performed the following day to ensure ovulation has occurred and there is no sign of fluid build up within the uterus which will adversely affect conception rates.

Weekends and bank holidays (here and abroad) can make semen collection and subsequent delivery difficult so timing the ovulation is very important in an attempt to have the semen arrive on the correct day. Please call the office to discuss relevant timings for your mare.

Frozen Semen

Mares entering into a frozen semen programme require more intensive veterinary involvement. As a result it is highly advisable that these mares stay at the practice for a short period as once defrosted; the semen has a very short lifespan (approximately 6 hours) and therefore requires inseminating into the mare at the time of ovulation to maximise conception rates. The semen must be thawed in a water bath at 37degrees celuis and when ovulation is imminent insemination is performed using a deep intra-uterine technique. This involves placing the semen at the entrance to the oviduct facilitating the coming together of live viable sperm and the egg hopefully resulting in a pregnancy.


We have devised a veterinary package for both fresh/chilled and frozen semen. This allows breeders to budget and prevents un-expected bills. Please contact one of our Veterinary surgeons for details of the packages.


Scanning for pregnancy is recommended to be performed on at least 2 occasions. The first scan is performed around 15-18 days post covering and the second examination around 25-28 days post covering. If you would like to attempt foetal sex determination, an additional scan must be performed around 60-65 days post covering.


Twin reduction is a procedure best performed as early in pregnancy (ideally before 17 days) as possible to minimise the risks of damaging the remaining pregnancy and ensuring there is enough time for the uterus to clear up the remnants of the reduced pregnancy. Your vet will advise you of the precise timings of the examinations required on a case by case basis.


The Horse Race Betting Levy Board (HBLB) advises that all mares should be swabbed for Contagious Equine Metritis (CEM) and blood tested for Equine Viral Arteritis (EVA) after the 1st January of each year before they are taken to stud. These venereal diseases are highly contagious and are notifiable by law. Some studs have different requirements concerning the timing of swabs and blood tests and should always be consulted first; many studs now insist on a Coggins Test (for Equine Infectious Anaemia)

A single clitoral swab can be taken at anytime during the mare’s cycle. In pregnant mares the swab may taken before or after foaling. (A second, endometrial swab, ie from the uterus, will be taken when the mare is in season just before covering.)

A single blood sample should be taken at a minimum of 28 days before the mare is being used for breeding activities. Breeding can only commence if no antibodies are detected. If the blood sample is positive a second blood sample is required.


Semen should arrive with a set of official health documents; these certify the health status of the stallion and stud from which the semen originates. If the semen does not arrive accompanied by health papers then we cannot inseminate your mare and significant time and money may be spent ascertaining the necessary information. If you decide to order semen from continental Europe or further afield, please ensure you do so through recognised and reputable channels to avoid any unwanted situations arising.