Frozen Semen
We recommend, that before reading this discussion, readers should first
understand the principles and reasons for using Artificial
Insemination (AI).
Frozen semen has become extremely popular in Australia in the last few years.
We have been freezing horse semen and breeding to mares with frozen semen
since 1984 (probably longer than anyone in Australia).
Follow the hyperlinks around these few pages and see if we can help you.
Why breed with frozen semen?
Breeding your mare with frozen semen
Freezing semen from your stallion at the
Goulburn Valley Equine Hospital.
Detailed information on freezing semen.
Why breed with frozen semen??????
It would be a huge mistake to dismiss the benefits of breeding with frozen
semen, however, there are some difficulties that everyone should be aware of. We
probably breed as many or more mares than anyone else in Australia to frozen
semen but still do not get all mares pregnant. The real 'cold hard' truth is that there are
some stallions who do not survive the freezing and thawing process very well.
Unlike the cattle industry who have culled bulls that didn't freeze well, we do
not have any (or much) selection pressure for freezability. In the future that
may come. Already we have frozen semen from stallions who were themselves
products of frozen semen. We think that this will result in a population of stallions that can
have good results from frozen semen.
What can we expect from frozen semen?
In well managed breeding programs with natural service or Artificial
Insemination (AI) we routinely expect around 70%+ of mares in foal per
cycle. Pregnancy rate per cycle is the only accurate indicator of fertility.
If you don't count the cycles and just add up the number of mares pregnant at
the end of the breeding season you can end up with impressive figures such as 95%+ of mares in foal for the season. Clearly this is not accurate and may
only really reflect how many cycles mares have been bred over rather than the real
fertility. With frozen semen very few stallions can achieve 70%+pregnant per
cycle. Only about 30% of stallions freeze well at our clinic, a further 40%
freeze marginally and the other 30% are discarded after looking at their post
freeze/thaw motility. To further complicate the issue, the only accurate
estimate of frozen semen fertility is the number of pregnancies compared to the
number of breedings. Fertility is not guaranteed even if motility looks great.
This all adds up to increased expense to determine if the semen from an
individual stallion is still good after being frozen and thawed.
As a potential client that is thinking of using frozen semen, stand back
first and
have a look at the probabilities of obtaining a foal.
In most natural or AI breeding programs the service fee is paid after a 45 day pregnancy test. 70%+ of mares are pregnant per cycle and at the end of the
breeding season 95%+ are in foal (we have previously published these figures).
When using frozen semen it is common to purchase 3 breeding doses of semen for a
set price. If more than one pregnancy results then that is your good luck (it
does happen) and if none of the breedings result in a pregnancy then there are
almost always no refunds. In some instances you are required to return the left
over semen once the first pregnancy has been achieved. We expect on average the fertility from frozen semen
to be approximately half of that achieved with fresh. In other words around 35%-40%
of mares are expected to get pregnant each cycle. Some stallions will do better
than this and we have bred with one stallion who routinely achieved a pregnancy
rate per cycle of 75% with frozen semen. However there are other stallions that
do not even reach 20% per cycle.
Only by knowing previous breeding results can you be comfortable with your decision
to breed with frozen semen.
So, what are the advantages (in
addition to those advantages of using AI):
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The primary disadvantage is that many stallions techniques
used for processing, packaging, freezing, thawing and insemination of their
frozen semen do not result in satisfactory pregnancy rates. Currently pregnancy
rates from frozen semen average approximately 50% of the same stallions
pregnancy rates with
fresh semen. However some stallions freeze quite well and some do not. In the
future selection for those stallions that freeze well may be expected to improve
the number of stallions with semen suitable for freezing and thus the per cycle
pregnancy rate. |
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Costs. Veterinary charges for freezing of spermatozoa are
quite high. At the GVEH our current charges are somewhere between $20-100 per
insemination dose This depends on a number of factors such as sperm numbers and
quality or if the semen is being frozen for export. |
|
Pregnancy rates from lay freezers (non trained
people) are poor and have helped create industry mis-conceptions about the difficulty of
working with frozen equine semen. Based on the results of frozen semen in
cattle, many
countries were quick to learn that semen frozen by most mobile units was
inferior to those samples frozen in major bull studs. A disadvantage of freezing
at centres is loss of control of the stallion to the handling of other people.
We have even had people send a handler in to manage the stallion (exercise etc)
while the semen is being frozen. |
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Common breeder misconceptions.
 |
Success rates are high. This tends to increase the number
of dissatisfied clients (usually those that have not been adequately informed
prior to beginning the freezing of semen). |
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That anybody can freeze semen. Lots of shipments of frozen
semen are arriving in Australia and occasionally the semen has been frozen by
inexperienced personnel. These people often have had only a small amount of
experience in sterile technique, laboratory procedures etc. Some of the samples
are good, however most are inferior. Once again this leads to client
dissatisfaction. We even have one person in Australia who categorically states
that when dealing with their group, the semen is always frozen well and the
problem must be with the lack of suitable veterinarians at the other end.
Unfortunately most people in this category are very good communicators and very
poor technicians. |
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Errors in identity. Many breeders are concerned that their
mare may be bred with the wrong semen. Obviously well marked straws and DNA
fingerprinting will eliminate these misconceptions. |
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What to do?
Use frozen semen if you can find a reputable dealer. Preferably
get them to agree to a fee when the mare is declared pregnant at 45 days.
Contact the Australian
Equine Veterinary Association (AEVA) to find a list of veterinarians
that are certified to use frozen semen. Do not use anyone else to perform this
exacting and difficult task.
Consider that the pregnancy rates for frozen semen are ~ 50%
of the pregnancy rates of fresh semen.
Ask your veterinarian if he or she has any information on the
fertility (using frozen semen) of the stallion that you are using.
Currently we are compiling a list of the fertility achieved
(per cycle) from all the stallions whose semen has been used by veterinarians that are AEVA certified. These
veterinarians will have access to a continually updated web-site and can use
this to help you formulate your breeding plan if that particular stallion has
been used in this country before.
Would you like details on our
semen
freezing services????
Would you like more detailed information on how
to freeze semen?????
Would you like to breed
your mare to frozen semen????
