The use of frozen semen requires expertise above and beyond that of fresh
or chilled semen artificial insemination. Camelot Farms and Symbiotic
affiliated veterinarians throughout the world are trained to handle frozen
semen inseminations. A current list of these veterinarians is available
from Monash Veterinary Clinic. It is important that:
- The bitch being bred is reproductively normal; frozen semen
use is not a solution to infertility problems
- Accurate ovulation timing is performed; since frozen semen lives
24 hours or less after it is thawed, it must be inseminated during the
short 2-3 day fertile period for conception to occur
- Frozen semen is handled and thawed properly
- Proper insemination techniques are used
Insemination Techniques
Each time semen is frozen from a stud dog, a small amount is examined
to assess the quality of the semen, and recommendations for use are made
accordingly. Three different methods of frozen semen insemination are presently
available for use in the bitch. In most cases, however, imported semen
is inseminated surgically, since this technique is the most reliable,
yields the highest rate of conception, and uses the lowest quantity of
semen.
Vaginal Insemination
In this simple technique semen is deposited into the
cranial vagina using a rigid pipette. No sedation or special equipment is
required; this is the same method used in most fresh semen and chilled
semen inseminations. Once deposited, sperm must travel through the cervix
into the uterus, and then into the oviducts where conception takes place.
Therefore, the motility quality of the sperm cells must be adequate for
them to travel this distance through the natural barriers present. In
addition, since most of the sperm cells do not survive to reach the site
of conception, total sperm numbers needed per insemination are high.
Historically, procedures necessary to enable canine
sperm cells to survive freezing and thawing also interfered with their
ability to reach the site of conception when inseminated into the vagina.
Considerable research and efforts by Camelot Farms using their frozen
pellet system, have been devoted to overcome this limitation. Higher
conception rates can now be achieved using vaginal insemination of semen
frozen in pellets. In general, vaginal inseminations may be used when:
- Post-thaw motility is 40% or greater.
- Post-thaw sperm motility quality is good.
- Sperm numbers are adequate.
- At least 200 million live sperm cells should be used with a
vaginal insemination.
Transcervical Insemination (TCI)
In this procedure, semen is
deposited directly into the uterus by passing a catheter through the cervix.
The bitch has an endoscope passed into her vagina to enable us to visualise
the cervix and then the catheter is inserted through the cervix. This
procedure is quick and does not involve a general anaesthetic. The bitches
tolerate this procedure very well, and it is suitable for most medium to
large breeds.
Passing a catheter can be
difficult in smaller breeds. If we are not able to pass the catheter then
the bitch will need to have an anaesthetic and a surgical insemination. TCI
allows us to do repeated inseminations 24 hours apart and so enhance the
chance of a pregnancy and a larger litter. The expected conception rate for
TCI is the same as for surgical inseminations.
Surgical Insemination
In this procedure, semen is deposited directly into the uterus via a
fast, simple surgical technique. Because sperm is placed close to the
site of conception, semen of low motility and/or poor quality may be used
and still achieve a high rate of conception. In addition, a reduced number
of sperm cells may be used per insemination, since more of the deposited
sperm will reach the conception site.
The bitch is placed under general
anesthesia. An incision is made into the abdominal cavity and semen is
injected into the uterus. Sterile technique is maintained. The expected
conception rate is usually 80-90%.Surgical insemination may be used when:
- Post-thaw motility is less than 30%
- Post-thaw motility quality is poor
- Total sperm numbers are low
- A breeding is particularly important to increase the chance
of conception
Quantity of semen to import
Frozen semen is stored in either small plastic straws or pellets. Pellets
usually provide a higher quality of semen. A breeding unit is that quantity
of semen required to produce a pregnancy at one surgical insemination.
The breeding unit is 100 million live sperm cells. To achieve 100 million
it may require 4 –10 straws, or several pellets. Vaginal inseminations
usually require twice this amount to produce a pregnancy.
The quantity
of semen obtained per collection is dependent on the dog's sperm count
and size. Most medium to large breeds produce 4-5 breeding units of 100
million sperm cells. Small dogs may only produce 1 –2 breeding units.
In general, a young mature dog (2-4 years of age) will have a higher sperm
count and better quality semen than older dogs or young immature dogs.
Breeders may need to import more than one ejaculation in order to obtain
sufficient semen for their breeding plans.
Breeders should contact the
clinic in advance of importing semen so as to ensure their needs are fulfilled. A
plan for the number of bitches to be bred, and the number of straws to
be imported, should take the above factors into account, to prepare everyone
involved for the expected time and costs.
Shipping
Monash Veterinary Clinic utilizes containers specifically designed to
ship frozen semen safely. The liquid nitrogen necessary to keep semen
frozen is absorbed into a matrix inside these containers, so that the
liquid cannot spill out and accidental thawing will NOT occur even if
the shipper is tipped or turned over. These containers hold the desired
temperature for two to three weeks. Your Vet maintains these shippers according
to a strict schedule. Shipments should be insured against accidental loss
or damage.
Specific steps involved
-
Investigate importation and registration regulations for the country
of importation. Obtain a permit.
-
Identify the stud dog you wish to use.
-
Make all necessary arrangements with the stud owner. The costs for
frozen semen and/or stud fees are between the stud and bitch owners directly.
-
Contact Monash Veterinary Clinic to advise us of your plans. Often
we are able to synchronize shipments and so reduce importation costs.
-
Arrange for semen shipping.
Costs
The stud owner will usually charge a stud fee, actual
fees for semen collection and freezing, as well as compensation for time
spent. Individual importation regulations frequently require specific
health tests be performed on the stud before semen freezing and/or
shipment, at additional cost. The inseminating veterinarian will charge
for ovulation timing, semen handling and insemination procedures. If the
semen is imported in advance of the breeding, there is likely to be a fee
for frozen semen storage.
More information, including a schedule of Fees, is available on the website listed below.
