Artificial Insemination
For years farmers have accepted the usefulness of artificial insemination
in the dairy and pig industry but the horse industry has been reluctant
to introduce this technique. There are many reasons for this but the
political and economic considerations have not really been tested. With
the aid of a suitable mare it not difficult to collect semen from a
stallion by means of an artificial vagina, the semen then can be split
into a dozen or so portions for use at a later date.
The technique of transporting chilled or frozen semen to the mare and
inseminating her artificially has become more popular with advances
in horse breeding. However, it requires great deal of synchronization
between the mare owner, stud and veterinary surgeon. Nevertheless, the
techniques are now being perfected and soon the bloodstock industry
will be challenged by the possibility of A.I.
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Disease control. If the stallion does not
physically touch the mare he cannot contract any form of venereal
disease. The Contagious Equine Metritis epidemic in 1977 had a profound
effect on the finances and reputation of many Newmarket studs; hence
the stringent and expensive precautions now in force on most studs.
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Reduced risk of injury to the stallion,
mare and handlers. The stallion never mounts a strange mare and therefore
avoids being kicked and thus put out of use.
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Semen can be stored so that it is ready
for use when the mare is at optimal mating. Insemination is carried
out at time the closest to ovulation thus improving conception rate.
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Semen is actually placed through the cervix
into the uterus of a mare at the right time.
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Greater effective use of the stallion,
the collected semen may be diluted in a special solution of nutrients
and antibiotics known as extender. The solution may then be divided
into several portions, enabling more mares to be serviced.
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Frozen semen is stored and transported
in liquid nitrogen tanks. This keeps the semen at a temperature of
196o C. If the temperature rises above this level for more than ten
seconds serious damage will occur to the semen. Great care is required
when transferring the semen between tanks.
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Frozen semen can be stored almost indefinitely.
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Mares would not need to visit the stud,
thus avoiding contact between visiting mares.
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The desired stallion may be a great distance
away; the semen can be quickly transported, saving time and money
travelling.
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The semen can be checked more frequently
for quality
Disadvantages of artificial insemination
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Legislation is probably needed to provide the
necessary safeguards if A.I. is to be widely used.
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Semen can be diluted, one stallion could father
thousands of foals in a season, thus making hundreds of stallions
redundant and putting most studs out of business.
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There is also a genetic argument against overuse
of stallions.
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Pregnancy rates are generally much lower with
frozen semen than with fresh or chilled semen.
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There is an inherently lower pregnancy rate with
frozen semen therefore it is not advisable for use on older mares
or those with suspect fertility.
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Mares must be inseminated within six hours of
ovulation. This requires a high level of veterinary input and therefore
expense.
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There is a slight risk that a mare may unwittingly
be inseminated with the wrong semen, therefore to ensure that the
mare was in foal to the right stallion, all resulting foals would
need to be blood- typed.
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Breed societies would need to endorse A. I. with
the A. I. certificates being legitimate and equal to covering certificates.
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Foals by A. I. are prohibited in any studbook,
however the position is not final.
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There are organisational problems to be overcome
if A.I. is to be used on an industry basis.
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Adoption of a national A. I. scheme is only feasible
with a National Horse Breeding Programme.
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There is a need for government intervention and
support, compared with continental breeding policies.
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Very high levels of knowledge and skill are necessary
for a successful A.I. breeding programme and the people who do the
insemination may be limited in their knowledge, understanding and
experience or have not receive proper training. The whole procedure
must be supervised by a veterinary surgeon, which increases cost.
