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Brown and white horse and its foal out in the yard together

Artificial Insemination

Artificial insemination (AI) is a popular procedure for breeding sports horses and leisure mares. It reduces the risks involved with natural covering and enables the use of semen from stallions worldwide. Twemlows is one of the UK’s leading AI centres and is approved by BEVA to provide AI services. Our skilled vets regularly perform successful inseminations with raw, fresh, chilled and frozen semen, depending on your mare’s individual needs. We boast consistently high conception rates at Twemlows with all forms of semen.

A logo to show that Twemlows is on the BEVA approved AI list

Pre-Breeding Examination

Breeding your mare begins with a fertility health check where we use ultrasound to examine her ovaries and uterus. This will highlight any potential problems, and allow us to determine which stage of her oestrus cycle she is in. You will have already had pre entry Strangles and EVA blood health tests done for your mare before she arrives with us. We may then take clitoral or uterine swabs and or additional blood tests if necessary, to ensure she is free from infection.

In order to provide the best service possible, we have a detailed discussion with you about her history, health, current activity levels, any previous reproductive history and your breeding wishes, so we can offer the best advice on how to proceed. Each mare is different and every mare we see gets their own tailored plan.

Fresh, chilled and frozen semen – what should I use?

Whichever stallion or semen type you choose for your mare, AI allows us to breed your dream foal. Fresh semen (from stallions who are nearby) and chilled semen (from the UK and Europe), typically give the highest conception rates. We are fortunate to be located next door to Stallion AI Services who are the home to several world class stallions.

Chilled semen is commonly used across the UK and Europe and arrives ready for use the following day. When using fresh and chilled semen we scan the mare regularly, to identify the best time to inseminate her, which is within the 12-24 hours before she ovulates. We perform a repeat scan 24 hours after insemination to check that she has ovulated.

Frozen semen, allows access to stallions worldwide and can be stored for future use, making it a fantastic option for rare or in-demand stallions. Thawed frozen semen has a shorter life span than fresh or chilled, which means it must be inseminated soon after ovulation. This requires more intensive management, and mares typically require more ultrasound examinations, to ensure the correct timing of insemination.

If semen is to be imported from Europe or the rest of the world, it will need an import health certificate, which the stallion stud or agent will be able to arrange for you. We can guide you or act on your behalf, when communicating with the stallion owner, to gather key information such as his semen availability and his first cycle conception rates.

Following Insemination

Following insemination your mare will be scanned to confirm ovulation and to check for any post-breeding inflammation. If needed, additional treatment will be carried out at this stage. Your mare will then be scanned again at 14-16 days post ovulation to determine pregnancy. We advise additional scans at 28 and 42 days to monitor the pregnancy.

AI BOOKING FORM

Artificial Insemination
Charges 2025

Veterinary Package Fees

  • AI Fresh & Chilled Semen
    £285 (+ VAT) per AI cycle

  • AI Frozen Semen:
    £415 (+ VAT) per AI cycle
  •  
  • Fetal Sexing Scan
    £80 (+ VAT) at 60 to 65 days pregnant

AI in Foal Fee

  • AI Mares : £175 (+ VAT)

Foaling Fee

  • £435 (+ VAT)
    (Mares must be booked in in advance)

Boarding Fee

  • £10.00 per day at grass (+ VAT)

  • £26.85 per day stabled (+ VAT)

  • £38.85 per day stabled (+ VAT) when requiring an individual paddock and/or the horse walker

  • + £2.70 per day for mares with foal at foot (+ VAT)

Long term boarders & over winter rates available on application

All fees must be paid before the mares leave the stud

Please read our full terms and conditions

T&Cs

Veterinary Contract:

Mares will be accepted with a veterinary package to cover routine veterinary reproduction work at Twemlows Stud Farm. Routine includes reproduction scans, standard reproduction drugs, a pregnancy determination (PD) scan at 14-16 days, a PD scan at 28-30 days and a PD scan at about 42 days.

It does not include swabs, twinning, caslicks, uterine lavage and the treatment of mares with endometritis and other non-routine matters, which if relevant are invoiced separately.

All mares that have been inseminated need to have pregnancy scans at 14 days and 28/30 days to confirm a single viable and healthy pregnancy. If mares leave the stud before the pregnancy scan it is the owner’s responsibility to arrange for this to be carried out.

Charges for a range of miscellaneous items, such as passporting/microchipping, farriery work, worming and any veterinary call-outs are available on request.