We offer an excellent AI service to mare owners using chilled semen from most of our stallions. There are several occasions when AI may be preferred to a natural service:

  • if the mare is injured and unable to travel
  • if the mare is a bad traveller
  • if the mare is susceptible to uterine infection
  • if the distance is so far as to make the transport impractical

Our aim at Catherston Stud is to breed top class stock – mares with poor confirmation or known hereditary diseases will not be accepted.  The Stud reserves the right to refuse any mare for Artificial Insemination.


In accordance with the recommendations of the HBLB we require all mares are tested for EVA prior to mating or insemination.  We would also suggest that you discuss with your veterinary surgeon whether a CEM swab is required.   All mares coming to the stud will require a CEM swab, EIA and EVA blood tests after 1st January 2016.


Full co-operation between the mare owner, Catherston Stud and the veterinary surgeon carrying out the insemination is essential.   It is important that Catherston Stud is kept informed of the mare’s progress and informed as soon as the mare comes into season during the months prior to insemination.   The attending veterinary surgeon should contact Catherston Stud to request semen.  Morning notification for the following day’s delivery is extremely important and should this fall over a weekend, Monday or Bank Holiday, early notification is always helpful and can make a large difference to the transport costs.   It should be remembered that the Catherston Stallions also compete and therefore any advance warning that you can give will help

Transport of semen

The chilled semen will be transported in an “equitainer” which will be sent by Royal Mail Special Delivery or by courier.   It should be noted that there is only limited transport by these companies on Saturday, Sunday and Mondays, so a special service may have to be arranged, or the deliveries made one day early.   The normal delivery time is 9.00am but a later delivery time can be arranged.  We will make every attempt to deliver as requested.  Due to the many variables associated with this we cannot, under any circumstances, make promises of delivery date or time, or even promises of availability continually throughout the season.

Once the semen is in the hands of the courier it is the property of the mare owner.


The Stud Fee is payable in full prior to the delivery of the semen, along with the Grooms Fee.  Charges for packing and shipping of semen are payable at the point of ordering.  Semen will not be despatched without prior payment.   We accept Bank Transfers, Cheques and Debit Cards.  Credit Cards will incur a 7.5% charge on the total amount prior to payment.  Our Bank details are as follows:  Catherston Stud   Sort Code 20-02-25  Account Number: 73450236  IBAN GB59 BARC 2002 2573 4502 36    Please use your surname & the mares name as the reference.


Under normal circumstances a polystyrene equitainer will be used.  This is preferable as it is more hygienic and incurs less carriage costs.  However there may be times where it is more appropriate to use the old style “Equitainer Bucket”.  The mare owner is responsible for the safe return of either Equitainer and any parts that are missing or damaged will be charged accordingly.

Polystyrene Equitainer hire including consumables                    £25 per delivery (inc VAT)

Royal Mail Special Delivery (Tuesday – Saturday)                    £30 per delivery (inc VAT)

Other carriage / courier services by arrangement.

Cancellation Fee

25% of the Stud fee will be charged for any nomination not taken up, unless a veterinary certificate is produced stating a valid reason for the mares not being inseminated.

Pregnancy Diagnosis

We recommend that all mares are examined by a veterinary surgeon between 16 – 20 days after insemination to confirm pregnancy and to spot possible twinning.  Mares should then be scanned again at 28 days to confirm a heartbeat and should twins have been missed there is an opportunity to remedy the situation.  (It is advisable to scan again at between 42 – 60 days to confirm pregnancy)  A further pregnancy confirmation should be performed in the last week of September and Catherston Stud notified of the result.

Covering Certificates

All certificates will be forwarded to the mare owner on receipt of a Positive Pregnancy Diagnosis certificate after the 1st October.

No Foal 1st October 20% Fee – Chilled semen only

If an artificially inseminated mare is certified not in foal by 1st October the stud fee will be returned less 20% which will be retained by Catherston Stud.  If a covering certificate has been issued then the stud fee will only be returned to the mare owner on receipt of the covering certificate.

Embryo Transfer

Specific contracts may be drawn up for embryo transfer and details should be discussed directly with Mrs Loriston-Clarke or Mrs Dicker.  Full information of the donor mare and the attending veterinary surgeon and recipient mares must be disclosed in the first instance.

Mares in foreign countries

Frozen semen can be exported from certain stallions.  We have agents in USA, Australia and New Zealand and contact details can be obtained from Catherston Stud.   For other countries, full details need to be forwarded to Catherston Stud who will arrange for West Kington Stallion Centre to deal with further arrangements.



This contract is non-transferable.  In consideration of the mutual covenants contained herein and for valuable consideration, the parties agree as follows:

1.    The Mare Owner understands that an examination of breeding soundness must be performed on the Mare and results reported to Catherston Stud prior to breeding with Frozen Semen, such examination to be carried out by a licensed Veterinary Surgeon and include a uterine culture.

2.    The Mare Owner understands that the “Certificate of Insemination” and “Certificate of Pregnancy Diagnosis” must be returned to Catherston Stud in order to receive a Breeding/Covering Certificate for foal registration purposes.

3.    The Stud Fee (breeding fee) as detailed in Schedule One to this Contract is payable by the Mare Owner in advance for the purpose of no more than three(3) insemination doses to be used in the breeding of one (1) live foal.

4.    The Mare Owner is responsible for payment to the Storage Agent of all local transportation and flask hire fees.

5.    Should the mare not become pregnant with the first insemination, a further two doses may be sent out individually.  Semen is transported one (1) dose at a time as once semen has left the Storage Agent it cannot be returned to them.

6.    There is no live foal guarantee.

7.    In the event that a viable pregnancy and / or live foal is not achieved, there shall be no refund of any fees to the Mare Owner.

8.    In the event that the Mare produces live twins, the Mare Owner shall pay to Catherston Stud an additional Stud Fee as set out in Schedule One to this Contract.


9.    The Frozen Semen shall be shipped in a liquid Nitrogen “Vapour Shipper” at the Mare Owner’s expense.

10.  WKS, on behalf of Catherston Stud, will ship the Frozen Semen in a viable condition from the UK to the Storage Agent.

11.  The Storage Agent shall be liable for storing, packing and shipping the Frozen Semen in a viable condition to the Mare Owner.

12.  Catherston Stud holds no responsibility for shipping errors, misrouting or mistreatment of the Vapour Shipper by the Storage Agent or the local shipping company.

13.  All transportation and insurance costs for the Frozen Semen and Vapour Shipper shall be the responsibility of the Mare Owner.

14.  The Mare Owner is responsible for payment to the Storage Agent of all transportation and Vapour Shipper hire fees prior to shipment of the Frozen Semen.  No semen shall be shipped until all fees have been paid.  The Storage Agent’s standard terms and charges are available upon request.

15.  The Vapour Shipper shall be sealed with a plastic tie wrap.  On arrival of the Vapour Shipper, it is the Mare Owner’s responsibility to ensure that this tie wrap has not been broken and that the container is frosty when first opened to transfer the Frozen Semen out of the Vapour Shipper.  If the shipment did not arrive sealed and cold, the Mare Owner must file a report of damaged shipment with the Storage Agent and courier company within 24 hours of shipment receipt.  It is the responsibility of the Mare Owner to file this report with the Storage Agent and courier company.  Catherston Stud and the Storage Agent are not responsible for damage howsoever caused to the Frozen Semen once it has left the Storage Agent’s premises.

16.  The use and management of the Frozen Semen is the sole responsibility of the Mare Owner and his/her Veterinary Surgeon.  It is the responsibility of the Mare Owner to procure liquid nitrogen storage (short term or long term) of the Frozen Semen.  The Frozen Semen must be transferred immediately from the Vapour Shipper into a viable liquid nitrogen Storage Tank and the Vapour Shipper returned to the Storage Agent.

17.  The Mare Owner understands that failure to transfer the Frozen Semen within 24 hours of receipt may jeopardise the viability and quality of the Frozen Semen and shall void this Contract.  The Mare Owner further understands that the Frozen Semen must be transferred very quickly from the Vapour Shipper to the Storage Tank.

18.  Catherston Stud assumes no responsibility for any loss or damage incurred to the Mare.  The Mare Owner assumes all responsibility for the condition of the Mare and shall bear all risk of loss or damage to the Mare whether by death, disease, injury, infection or other cause.  The Mare Owner further agrees to indemnify and hold harmless the Stallion Owner for any and all damages and /or liability.

19.  This Contract follows the Mare as detailed above and in Schedule One to this Contract and may not be transferred to another Mare or Mare Owner without the prior written agreement of Catherston Stud.

Catherston Stud are able to hold and store frozen semen on behalf of mare owners who wish they mares to come to stud to be put in foal to external stallions.