1 March 1996

AI only way to put UK

on the map

BRITISH breeders have been slow to reap the benefits of artificial insemination. But many top breeders have decided it is a breeding technique that must be exploited if British stallions are to be put on top of world rankings.

The minimal use of AI in horse breeding – less than 1% of coverings – may seem alien to farmers who have bred cattle in this way for many years. The reasons for this are partly technical and partly the reluctance of some breed societies to support the practice.

To rile British stallion owners further, much of the AI in this country uses imported semen, particularly from Germany. However, where there is enough collective will, anything can be achieved, and this year eight stallions were taken to an isolation yard in Avon where semen was collected, then frozen for the export market.

Some of the UKs top performance horses were there, bringing their combined value to £600,000. Their number included Welton Crackerjack, sire of several international three day event horses and Its The Business, international show jumper with winnings of £30,000.

The initiator was Tessa Clarke. Formerly stud manager with Jennie Loriston Clarke, Tessa is now with Jane Holderness-Roddam,another Olympic medallist. "Jane said I would be free to try an out-of-season project, and when some owners were contemplating sending their stallions abroad to cover mares – with all the cost and stress which that would entail – AI seemed a better way forward.

"We have worked closely with vet Martin Boyle for several years, using fresh and chilled semen to inseminate home-based mares. Export opportunities are limited because many countries would not accept imported semen and, with chilled semen surviving for 48 hours or less, it was impossible to reach distant markets such as Australia."

Her idea was spurred on by the EU which in Oct 1995 introduced regulations permitting the trade in frozen semen throughout the community, provided it had been collected at EU-approved centres. "This was a great breakthrough because we can now export to countries such as Germany where we know we have a good market."

Martin Boyle comments: "In this country we have lagged behind many of the overseas breeders in the use of AI. This is partly because we are dominated by Thoroughbreds. Thoroughbred breeders worldwide are opposed to the technique. In the past 10-15 years frozen semen techniques have developed to the extent that the process is now commercially worthwhile for many stallions.

"Originally it was thought that stallion semen did not freeze well. This was because people tried to adapt cattle techniques for use in horses. This was doomed because the two species are completely different in the way semen is deposited in the female. In addition the seminal plasma of stallions can be harmful to sperm during storage."

These points mean that the ejaculate must be extended immediately after collection. It must then be centrifuged to concentrate the sperm and separate them from the seminal fluid. None of these stages are necessary when freezing bull semen. Finally, the concentrated pellet of sperm is resuspended in a freezing medium of egg yolk and glycerol and sucked into straws and frozen.

To match the expertise on the straw production side, the timing of insemination is critical. For a cow it can be any time during the relatively short period of bulling. In a mare ovulation may occur at variable times during the five to seven days of heat.

Once thawed frozen semen has a short survival time in the mares genital tract, which means for the best chance of conception, insemination should take place in the period from 12 hours before to six hours after ovulation.

Therefore, vets experienced in follicular development scan the mare every eight hours so she can be inseminated at just the right time. Using this technique a company importing frozen semen claims 50% conception at first cycle and 80% at second, which is equivalent to natural service.

In Tessas project the stallions settled down well, and despite being out of season all performed every other day.

Individuals showed wide variation, single collections producing anything from eight to 20 straws. There was always the possibility that some of the stallions would have sperm which, although perfectly fertile for natural matings, would be too fragile for freezing.

At least the results made it a profitable exercise for all the stallion owners. Several will command fees of over £1000 for every foal produced. Tessa comments: "This is an exciting project, and we hope that it could be the first of many organised collections.

"If this works, which is certainly looking the case, there are huge growth areas. Most benefit will be out of the normal stud and competition season.

"Competition stallions could carry on competing and export markets will be opened up. We already know that Jumbo has a huge demand in Australia. There is also great interest in our native breeds, particularly the New Forest pony.

"Also it gives the opportunity for really successful stallions reaching the end of their working life, such as Welton Romance, now 23 to put some in the bank."

Inquiries to Tessa Clarke (01249-783064).

A full AI service is also available for Farmkey Equine Breeding Services, a subsidiary of Genus.

The semen collection and freezing service is based at the Farmkey Stallion Centre in Ruthin, North Wales. Vet Stuart Revell, heads the team collecting and processing the semen. "Export of semen can be arranged to Europe and Australia," explained Stuart.

The stallion centre also offers an on-yard semen collection service, and full on-yard AI service.

Farmkey inquiries: John Berry (01270 536584).

FERTILITY, nutrition, foot-care and farriery will be among the subjects of papers presented to the Shire Horse Societys World Congress* over the three days leading up to this years National Shire Show*at Peterborough.

The show will be spread over two days (Mar 16-17) with stallion and gelding classes

on the Saturday and mares and fillies on Sunday. Turnout and farriery classes and a grand parade take place on both days.

There is a reduced price for tickets purchased in advance. *Inquiries (01733-234451).

Vet Martin Boyle assesses the sperm for motility and works out the quantity of diluent to be used.

The semen is centrifuged to concentrate the sperm and separate them from seminal fluid. Concentrated sperm is resuspended in a freezing medium.

Above:Tessa Clarke, initiator of the Avon-based AI collection project, with Welton Crackerjack, sire of many top eventers. Right: Collecting semen from stallion Dutch Dream. A mare is used to encourage him to perform.