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| Equine AI & the Use of Frozen Stallion Semen in the British Isles Taken from - "Stallions - The Leading Competition Sires of Great Britain and Ireland" by Hugh McMahon. Published by Otterswick Publishing. It is little more than a decade since breeders in the British Isles began to realise that artificial insemination (AI) might have a useful role to play in horse breeding. Before, that, most breed societies would not register foals conceived by AI and there were a number of widely held misapprehensions about the technique. Many people were convinced that, if permitted, the use of AI would inevitably lead to a variety of abuses ranging from rampant fraud to a narrowing of the genetic base in breeds because a few favoured stallions would cover big books of mares to the detriment of less popular sires. In the past few years, however, the situation has changed dramatically and the use of AI has become well established for breeding non-Thoroughbred horses in both Great Britain and Ireland. Greater familiarity with the technique has shown that many of the perceived objections to it were groundless. Careful certification, backed up by wider use of blood testing, has eliminated the worst consequences of fraud or error. In addition, the practicalities of AI in horses, which differ markedly from those in cattle, mean that the risks from over-using individual stallions are less originally feared. As a result, approximately 80% of the studs in "Stallions" 1996/97, The Leading Competition Sires of GB & Ireland, published by Otterswick Marketing Ltd offered mare owners the option of AI and most major breed societies, with the exception of the Thoroughbred, now accept registration of foals bred by artificial methods. At present, most of the AI practiced here involves the use of semen stored in liquid form (usually chilled to 4ēC) where maximum survival time of the sperm is unlikely to be more than 72 hours and is usually considerably less. Nevertheless, where correctly used, semen kept in this way can give conception rates at least as good as those possible with natural mating and moreover, greatly increases the opportunity open to breeders. AI with frozen semen has been slower to catch on in Britain although it is increasingly popular with breeders in the rest of Europe and in the USA where a considerable trade in imported and exported semen has developed. For many years, the development of frozen semen was held back because of disappointing conception rates was held back because of disappointing conception rates. An early survey reported that 20% of stallions produced semen that retained good fertility following freezing. Poor initial results created a conviction amongst many breeders and veterinary surgeons that AI with frozen stallion semen was too unreliable to be worth considering. This is an impression that is only slowly beginning to dissipate. In fact, research and increasing experience have led to great improvements both in freezing techniques and in mare management and insemination. It is now probably true to say that semen from a majority of normal stallions could successfully be used in an AI programme with frozen semen. As a result, the past three years have seen growing use of AI with frozen semen by breeders on both sides of the Irish Sea. The Ministry of Agriculture, Fisheries and Food (MAFF) revealed that the number of consignments of frozen semen imported to the UK grew by over 200% between 1993 and 1995. Furthermore, as is reported elsewhere, the number of mares inseminated with frozen semen supplied by International Competition Stallions from top class showjumping and dressage stallions from the continent and the USA increased by 500% between 1994 and 1995 with a result that over 100 mares were inseminated with this semen in the past breeding season. It is, perhaps, more significant that owners of stallions based in the British Isles are also beginning to take advantage of the opportunities offered by frozen semen. Competition stallions have been able to combine both stud and competition roles. Semen can be collected during rest periods and then stored for insemination in the breeding season whilst the stallions continue their jumping or dressage careers uninterrupted. Another exciting development is that more and more semen from stallions standing in the British Isles is being exported. In the past three years, a large consignment of Irish Draught semen was sent from Ireland to the USA and semen from English ponies and competition stallions has gone as far afield as Australia and Southern Africa. Because conception rates have generally been good and the progeny born so far has been highly successful, theses markets are set to expand. As an illustration of the sort of conception rates that have been achieved, the first year frozen semen from British pony stallions was sent to Australia, all eight mares inseminated produced foals. Furthermore, International Competition Stallions reported that, during the past breeding season, the conception rate of mares inseminated with frozen semen provided by the firm was 50% after the first cycle. After two cycles, over 80% of the mares were in foal. Although figures such as these are impressive, it must be emphasised that they were only achieved as a result of the skill and the close supervision of the mares by those involved with inseminating the semen. Frozen semen is fragile and needs careful in handling during thawing and insemination if it is to retain its fertility. After thawing, the sperm have only a short survival time of in the mare's genital tract and must be be inseminated close to the point of ovulation en if a conception is to occur. To judge the correct time to inseminate requires considerable skill and experience on the part of c the inseminator and frequent examination 1 of the mare, preferably with an ultra- at sound scanner, at the relevant period in her en cycle. These are procedures that should be carried out only by suitably experienced 5. veterinary surgeons. This attention is costly and time consuming but, without it, the ˇ chance of obtaining an acceptable conception rate with frozen semen is highly unlikely. For this reason, many stallion owners and ˇ suppliers of frozen semen insist on retaining some control over who inseminates ˇ semen provided from their horses. This is because each insemination dose is relatively expensive to produce and, if the ˇ semen is badly handled and mares do not become pregnant, the poor fertility figures ˇ reflect . unfairly on the stallion. To help semen importers and horse breeders get ˇ suitable advice on AI and to ensure that preserved semen is handled and inseminated with the necessary degree of competence, the British Equine Veterinary Association (BEVA) maintains a list of ˇ practices with a particular interest in equine AI. The list is obtainable on request from BEVA (01249-715723) and all practices on it are inspected regularly to ensure that the necessary facilities are available. With the aim of encouraging sensible procedures and of providing a practical framework, BEVA has also produced a code of practice for those using AI. Apart from this, there is little effective control over equine breeding here and there is no way of ensuring that those practising AI in horses are adequately trained or supervised. This is in contrast to most of our neighbours in the EU where there is statutory control over all equine breeding. Most of these countries permit lay inseminators to operate but ensure that they are fully trained, that they are adequately supervised and that their results are monitored. In this way, standards can be maintained and abuses, especially those affecting the welfare of the mares involved and the dissemination of disease, can be avoided. This control, and the availability of training and supervision, are some of the main reasons why equine AI grew more rapidly and successfully in countries such as France and The Netherlands than it has done here. Talks are taking place between MAFF and the Royal College of Veterinary Surgeons to try to establish a similar system in the UK.This is a long term venture; it won . Id be some considerable time before a suitable framework of supervision and official training courses could be established. In the meantime, it is important that there should be close collaboration between all sides of the horse breeding industry and the veterinary profession to ensure that AI is used responsibility. It is essential that those using AI have the necessary experience and receive appropriate advice and help. Otherwise, conception rates will be disappointing, the incidence of venereal disease will rise and, as a consequence, the technique will fall into disrepute. One encouraging development is that, after several years of negotiation in Brussels, agreement has finally been reached on regulations governing trade in equine semen within the European Union (EU). Since 1st October 1995, it has been possible to trade both chilled and frozen semen between all member states of the EU. There is no requirement for stallions to undergo a period of quarantine before semen is collected. However, in order to be eligible for trade, the semen must have been collected in an approved semen collection centre under the supervision of a veterinary surgeon and the stallion must have undergone a number of health checks before the semen is traded. This is an improvement on the situation that has existed until now when trade in semen depended on bilateral agreements between the relevant ministries of the individual countries concerned. The UK had agreements with only a limited number of states; these agreements seldom covered both import and export and requirements varied from state to state. Where bilateral agreements did not exist, they often took many months to set up before semen could be traded. Breeders frequently found these requirements complicated, long-winded and restrictive. The frustration this caused led many to abandon attempts to trade in semen. The new regulations should lead to an increase in both the import and export of semen from the British Isles. It is emphasised that there can be considerable disadvantages to AI and it is certainly not a cheap and easy alternative to natural mating. However, if correctly used, it can contribute significantly to overcoming a number of problems commonly met with by breeders. It opens up new markets for stallion owners and provides mare owners with a choice of stallions that would not otherwise be available. Many of the objections that caused the technique to be distrusted by horse breeders in the past are now no longer valid and AI, especially with frozen semen, is sure to become increasingly common in the future. However, AI is certainly not appropriate for all breeding situations and horses will continue to be bred successfully both with and without the use of artificial methods. |