 Artificial Insemination in
the MareOur Island situation
makes the breeding of mares both difficult and expensive and an option that we have taken,
with reasonable success is the use of artificial insemination (AI). There is little doubt
that sending your mare ‘to stud’ is probably the most successful way to ensure
pregnancy but there are many problems; considerable expense, her being away from home and
your care for several months, the potential of damage and ill health at the stud when
being covered or when turned out. AI has low disease risks, is relatively inexpensive and
you can continue using your horse for most of a season (pregnancy is not a disease!).
Because of the small number of horses on the Island
and the lack of stud work the facility of ultra sound scanners, at the time of writing,
are not available. However, this is not essential for successful AI, as manual palpation
of the ovaries can determine many of the features required for successful insemination. We
recommend the use of chilled semen, rather than frozen semen due to the difficulties and
potential dangers of shipping liquid nitrogen containers and keeping them in Guernsey
without full back up facilities.
We follow the protocol listed below:
The mare should be of a size suitable for manual
rectal and vaginal examination (138cm / 13.2hh or larger).
She should be in good health and have had no past
history of urogenital disease or failure to conceive.
Ideally, she should be a mare who is easy to
determine when she has come in season. Many mares respond when ‘teased’ with a
gelding.
It is up to the owner to chose a stallion suitable
in temperament, performance and size and standing at a stud prepared to collect and ship
semen to Guernsey.
The mare should be swabbed between the third and
sixth day of a season for bacterial organisms which may prevent a successful pregnancy.
This gives us an opportunity to examine the ovarian structures, the uterus and cervix. The
swabbing is usually performed under light sedation.
The swabs are sent to a registered laboratory in
the UK and results are obtained within a fortnight. A certification of sound health will
be issued.
To determine the optimum time for insemination,
regular rectal examination of the ovaries will be necessary at the next season. We start
this usually on the third day of the season although occasionally this has to be performed
at an earlier date. It may require twice daily visits.
Once a follicle measuring 3.5 to 4cm in diameter is
palpable a hormone injection called chorulon is given. This will induce ovulation
approximately 36 hours later.
As soon as the chorulon is given, the semen
collection should occur and transportation by courier to Guernsey (most airlines will act
as carriers from the airport) arranged. We would recommend that all paperwork and customs
declarations are prepared in advance.
The mare is inseminated at least once, under
sedation, 24 hours after giving the chorulon.
Most studs request that the mare has her uterus
infused with an antibiotic solution (we use excenel) and given a hormone called oxytocin,
24 hours post, insemination.
Pregnancy diagnosis by manual palpation at 28 days
and with a blood sample at 60 days is recommended.
We would like to emphasise a number of points:
AI is probably only 60-70% successful. There is no
substitution for a successful stallion!
If dystocia (difficulty in giving birth) occurs, in
many cases we will be able to help with rectifying the problem manually but if not, there
is no facility for caesarian section in Guernsey.
We cannot guarantee that twins will not occur.
At the time of foaling owners must have arranged a
suitable foaling box or paddock. A normal box is too small.
Foals do not understand about electric fences,
Guernsey banks etc and a suitable foal enclosure should have been arranged.
Guernsey land is naturally calcium deficient and
often requires liming. The pasture for the foal should have been tested for its nutrient
consistency and treated accordingly to ensure adequate calcium and other nutrients for
good bone growth and development in the foal.
We would not recommend breeding from a maiden mare
older than 14 years of age.
Please telephone (01481 723863) or e-mail the
surgery if you require additional advice. |
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