The breeder should get as much information as possible about the procedure so that they are fully informed about their decision.

 

Reasons for using frozen semen

Frozen semen is generally used from imported semen and considered a cheaper way of acquiring superior genetic stock from abroad. Frozen semen can also be used from local studs if the donor dog is no longer alive or fertile. In my opinion it makes no sense to use the frozen semen from a local dog that is still alive, well and fertile. Better results can be obtained at lower cost by acquiring that stud’s services via natural mating or fresh semen insemination.

What to do first when planning the use of frozen semen

Contact the veterinarian that will perform the insemination. If you have not yet purchased the semen or imported it get your vet to inspect the post thaw examination report on the semen so that they can evaluate the quality and advise on the number of straws or pellets required that you should ideally import.

How much semen (straws or pellets) should you import?

Usually a breeder wants to import semen from a much-desired stud merely to have a very special bitch impregnated by that stud. The breeder should ideally plan to import enough sperm to be frozen to have a bitch inseminated during two heat periods, each time allowing for 2 inseminations per heat period. The ideal number of sperm required per insemination is 50-100 million progressively motile sperm after thawing. The number of straws means nothing if the number of progressively motile sperm are not known. The ideal of 100 million progressively motile sperm may be contained in as little as 1 or as much as 6 straws depending on concentration and quality. Likewise with pellets one should make sure that you get the required quantity of sperm.

Request the exporter to supply a report that was issued by the veterinarian (not the owner of the stud) on which the quality is stipulated.

How easy is it to import the semen

Remember that there is a considerable amount of administration and health tests (on the stud) that needs to be performed before the semen will be released for use. Time schedules of people that need to freeze the semen abroad may also be a limiting factor. For this reason, the breeder who wishes to import semen for a specific bitch should start with arrangements not less than 3 months prior to the time when the bitch is due on heat. For most breeders it is ideal that they contract an entity  to import the semen on their behalf. They are familiar with all the legal requirements and have access to correct freezing vessels for the purpose.

It is ideal that the semen is already in the country by the time that the breeder plans the insemination.

Selecting the prospective bitch that the breeder wishes to use the frozen semen on

The breeder may select a prospective recipient of the frozen semen based on sentiment or genetic merit. It is however very important that the breeder also consider reproductive health in this selection process. It is ideal that younger bitches of proven fertility that have bred successfully at regular intervals be selected for this purpose. All too often breeders earmark much older bitches which have not been bred for many heat periods as recipients. These bitches are less likely to conceive, have smaller litters and have a higher incidence of pyometra following insemination attempts than their younger counterparts.

 

To summarise

  • Select only genetically superior bitches to justify’ the cost involved and to ensure that genetic progress will be made.
  • Select a bitch whose fertility is expected to be good. The ideal bitch to use is the one whose fertility has already been proven by the fact that she has had at least one litter about one year prior to insemination. Breeders are thus advised to first have bitches bred naturally during one heat before having their bitches inseminated with frozen semen.

 

The following categories of bitches are not ideal candidates to inseminate with frozen semen.

  • Bitches that have been treated with hormones.
  • Bitches that are already 4 years or older without ever having had a litter
  • Bitches that have not been bred in the past two years prior to the intended insemination using frozen semen
  • Bitches with a history of genital disease or infertility.

Even the best quality frozen semen may be totally wasted if inseminated into a bitch that has never been bred, had problems to conceive before, or is suffering from any kind of genital disease or reproductive disorder.

How soon should the bitch be presented for monitoring of her cycle

The breeder should present the bitch within the first 4-5 days of showing the first signs of heat and if in doubt bring her in at the first signs of heat. This is important because the optimal timing of insemination depends on the rise in progesterone hormone which occurs early on in the cycle. Regular access (every second day and later every day) is required for up to 9 days or longer. Some owners find this very frustrating but it is important that this process be done correctly.

Transport of the frozen semen from the semen storage bank to our facility.

Once the optimum days for inseminating the bitch have been established, we will take care of getting the semen from the semen storage bank to our clinic and keeping it there safely until insemination. We have all the required equipment and expertise to do this. The owner of the semen will be required to send an instruction to the semen bank allowing us to collect the required number of straws or vials containing the frozen semen pellets on their behalf. This can be done by email or in writing.

How many times should the bitch be inseminated

The window during which eggs in the bitch are fertilizable in the bitch is around 48-72 hours and the time that the thawed sperm remain fertile is around 11 hours. Therefore optimal timing of the insemination during this narrow window is critical. As mentioned before it is ideal that there be enough semen to inseminate the bitch using more than 50-100 million progressively motile sperm on two consecutive days within this window. This is however not always possible as often there is just not enough semen available. In this case the veterinarian will select the most suitable day on which to inseminate the bitch this one critical time.

Which method can be used to inseminate the bitch

Frozen semen inseminations have to be performed by depositing the semen directly into the uterus. There exist different methods of inseminating a bitch into the uterus. Fresh semen may be inseminated into the vagina because the sperm are vigorous enough to find their way to the eggs and live long enough to wait for eggs to arrive or mature. Frozen semen has limited life span following thawing and is less vigorous so they must be deposited close by their target. The semen may be deposited directly into the uterus via surgical means or via trans cervical insemination (TCI) using endoscopic equipment. The surgical route requires anaesthesia for a couple of minutes and a small cut in the abdomen. The TCI may require nothing in cooperative bitches or a tranquiliser. Depending on the case, the breed and the operator, the TCI may take longer than the surgical method. It is also important to note that in some bitches the TCI may not be possible after several attempts and that surgical insemination may still be required in those cases. It is also important to note that many semen banks recommend using a higher dose of sperm when TCI is used as opposed to when  surgical insemination is performed. Our clinic only uses surgical insemination.

 

What results can one expect when using frozen semen

Given that the semen is of good quality, that there is enough semen to perform two inseminations and that the bitch is of normal fertility and an ideal recipient, the expected probability of conception is around 65% with slightly smaller litters, otherwise it is less.

The concept of using a “top-up” male after the last insemination with the frozen semen and comments on frozen semen quality

The cost of frozen semen insemination is high. The results expected with frozen semen is lower than when using fresh semen. This is even more so when it becomes evident that the frozen semen used is of very poor quality. Unfortunately the veterinarian that has to inseminate the semen is often confronted with the reality that the frozen semen that they thawed does not nearly meet the progressive motility than stated on the paperwork. Unfortunately this fact is only realised on the intended day of insemination. The probability of singleton litters and two pup litters are also somewhat higher than normal. Therefore in all cases we strongly advise the use of a “top-up” male after the last insemination with the frozen semen. Given the fact that frozen thawed semen is unable to fertilize 12 hours following its deposition into the uterus, it makes perfect sense to inseminate the bitch (through the vagina) using fresh semen at least 12 hours after the last frozen semen insemination but before the bitch is totally off heat (dioestrus). This has the advantage that it reduces the chance of not conceiving, and reduces the probability of smaller litters. The puppies resulting from this may be as follows; all from frozen semen, all from fresh semen or more commonly a mixture of the two. There is no problem with the registration of such litter provided confirmation of parentage is confirmed. If the DNA profile of the stud is not known we always collect a microdrop of the semen to have this done on the semen.

Conclusion

The use of frozen semen offers a practical tool to help attain the goal of acquiring top-quality genetic stock. This technology, however, demands a dedicated breeder, a dedicated veterinarian to freeze the semen and a dedicated veterinarian to inseminate the bitch.