Rossdales is approved by the British Equine Veterinary Association to provide artificial insemination services (AI) with chilled and frozen semen for non-Thoroughbred stud farms and individual mare owners.
Whilst AI is not permitted for breeding Thoroughbreds, it is now a very popular and routine procedure for breeding sports horses. Health and safety benefits are well recognised and conception rates with fresh or chilled semen often equal or exceed expectations from natural service. The process involves monitoring the oestrus cycle of the mare to be bred and inseminating her close to ovulation with either fresh collected semen, fresh chilled semen or frozen semen. Successful AI depends on a detailed understanding of the mare's oestrus cycle, a comprehensive understanding of the mares breeding history and in some cases the use of advanced reproductive techniques. Rossdales have performed many successful inseminations, ranging from straightforward mares to more complex cases, and offer a comprehensive AI service to our clients and referring veterinary practices.
Prior to breeding your mare, a full reproductive examination should be performed and will allow the veterinary surgeon to assess her suitability for breeding and highlight any potential reproductive problems. A full reproductive history is very useful, as this will enable prompt initiation of treatment prior to or after insemination if required. If insemination is to be performed at an AI centre, often clitoral swabs for contagious venereal disease will be required alongside blood samples for infectious disease prior to entering the stud. This is now becoming a very routine requirement for all major insemination centres across the country.
Initial reproductive examination will allow assessment of the stage of you mare's oestrus cycle and will determine timing of repeated examinations prior to insemination. Mares may be subjected to an endometrial swab at this stage, which allows the assessment of the requirement for pre or post breeding treatment such as antibiotics. Follicular activity is followed closely alongside other parameters and when the follicle has reached a suitable size for breeding, hormones will be given to induce ovulation. Timing of induction will be largely determined by which semen is chosen (see below) and which induction agent is used. Induction agents can be in either an intravenous or intramuscular injectable preparation or in the form of an implant injected either under the skin of the neck or vulva.
Semen may be available either fresh, chilled or frozen and management of the mare and timing of insemination will be determined by which semen is chosen. For fresh or chilled semen, conception rates are highest when insemination is performed within 24hours preceding ovulation. Frozen-thawed semen has a relatively short life span and therefore requires that mares be inseminated immediately before (within 6 hours) or after (within 4 hours) ovulation. Subsequent management of mares for insemination with frozen-thawed semen is more intensive and mares require multiple ultrasound examinations to assess the correct time for insemination. Conception rates for mares using frozen-thawed semen are often lower and therefore ideally this should be reserved for mares with the best reproductive histories. Insemination with chilled semen requires good communication with the stallion stud so that semen is delivered on time.
When ready for insemination, the mare's perineum is thoroughly cleaned and the semen is prepared. Using a sterile glove the semen is inseminated through the vagina into the uterus via a uterine catheter. Semen may be deposited into the uterine body or by deep intrauterine insemination into the horn of the uterus. Occasionally advanced techniques such as low dose insemination or endoscopic guided insemination are used in problematic mares.
Following insemination, your mare will be checked for ovulation and for post-breeding inflammation. Treatment may be required following insemination, especially in older or problematic horses. Provided all is well, your mare will be scanned at 16 days following ovulation and if pregnant, it is advised that scans be performed at 28 and 45 days to make sure the pregnancy is developing normally. Older or problematic mares may require treatment, such as supplementary progesterone in this early period.
Maiden mares, older mares or mares with predisposing reproductive problems can be very difficult to either conceive or maintain pregnancy. Advanced techniques may be required in these cases prior to, during and following insemination. These cases often can be hugely time consuming and require additional expenditure; however, if successful, they are usually the most rewarding to get in foal.
Rossdales is fortunate to have a large AI centre positioned close to the practice and one of our veterinary surgeons routinely visits the centre daily. A comprehensively priced AI scheme is offered through the stud for both fresh/chilled and frozen semen.
If you would like to discuss the possibility of using AI in your mare, or have any questions regarding AI or the schemes available, please contact Chris Phillips, Andrew McGladdery or Fred Barrelet for further information.