ARTIFICIAL INSEMINATION

Fresh Semen Insemination

The semen used in artificial insemination may be in one of three states; Fresh semen, Chilled semen or Frozen semen. The reasons for choosing artificial insemination may vary and are discussed below. Please note that it is advised that all bitches be fully vaccinated at the time of insemination and that additional vaccination against kennel cough (specifically Bordetella bronchiseptica) is strongly advised in attempts to prevent kennel cough associated bronchitis which may reduce conception rates as well as cause bronchopneumonia in puppies (often fatal) in the breeding colony which may rapidly spread. Vaccination against Herpes virus is also strongly advised.

Fresh semen insemination per vagina

Fresh semen insemination is typically chosen if

  • Poor results were obtained at previous attempts with either the stud or bitch and fertility assessment including optimal timing of breeding and semen evaluation is indicated
  • Stud has difficulty in mating naturally
  • Bitch does not allow mating
  • Bitch displays unusual heat cycles (aberrant heat cycles)
  • Managing a stud that is known to suffer from suboptimal fertility
  • Semen is intended to be used on numerous bitches simultaneously
  • Manage limited access to studs in high demand (only one or maximum two matings are allowed)
  • Multiple sire matings are planned

How does the procedure work?

The bitch should be presented for monitoring of her oestrous (heat) cycle from about the fifth to sixth day since the bitch was first suspected to be in heat. When in doubt bring her in as soon as the first signs of heat are noticed. The monitoring can be done using simple vaginal speculum examinations or progesterone and LH blood assessments in more complicated cases. One “flat rate” is charged for artificial inseminations irrespective whether one or more inseminations and examinations are performed. In exceptional cases up to four inseminations are performed. The reason for the “flat rate” is to ensure that we maximise compliance from the owner to present the bitch at the required intervals. We need to have access to the bitch every alternate day in early heat and every day in late heat. We prefer to deal with the bitches on an outpatient basis but if that is not possible we can hospitalise the bitch for the duration of her heat cycle. In the latter case a boarding fee for both the stud and bitch applies. Bitch owners can expect their bitches to either stay a week or longer or having to present them for that long. Owners wishing to limit these visits somewhat may opt to have progesterone performed in which case the bitch should be presented from about day 4-5 following first signs of heat.

Fresh semen insemination directly into the uterus

This mode of insemination is becoming increasingly popular. The insemination of fresh semen directly into the uterus is indicated when:

 

  • A bitch has repeatedly failed to conceive without apparent cause
  • Semen of questionable quality is used
  • The veterinarian wishes to visually inspect the internal genital organs for pathology

 

There are a number of reasons why freshly collected semen inseminated directly into the uterus may have advantages over insemination into the vagina.

What is chilled semen?

Chilled semen is semen that is freshly collected, extended with a special media and gradually cooled to, and kept at 4-5°C during transit in a special container. The cooling rates which are required are very important and deviations from these results in poor sperm survival. When kept in this way, the sperm cells are nourished and protected and remain fertile for in excess of 2 days although we prefer to use the semen on the same day as collection.

Why use chilled semen?

The main indication for using chilled semen is to inseminate a bitch that is in another province of the country to the stud. Chilled semen is a cheaper alternative to frozen semen. Chilled semen is not suitable for transport from overseas as the time delay may be too long and delays are expected with regulatory papers and arranging flights in time. Chilled semen insemination requires a veterinary surgeon to monitor the oestrous cycle of the bitch in order to determine, one to two days in advance, when the optimal time is for fertilization. This vet determines when the semen should be collected. A veterinary surgeon needs to be available on the stud’s side to collect the semen and process it correctly.

What are the first steps to take if a breeder plans to make use of chilled semen?

The breeders should contact the veterinarian that will be collecting the semen, processing it and sending it to the veterinarian that monitors the cycle of the bitch. It is strongly advised that both the veterinarians involved are familiar with these specialised procedures and remain in close contact at the time of the insemination. It is of VITAL importance that the breeder presents the dog to the involved vet for a preliminary evaluation. This is necessary to establish whether the stud’s semen is of adequate quality to use for chilled semen purposes and whether it is easy to collect a sample from the stud. It should never be assumed that the stud is a suitable donor for chilled semen based solely on the fact that he has produced a litter some months before. Semen of mediocre quality may in some cases result in conception, but this very same semen may not perform well when chilled because of suboptimal quality. It is not fair to the bitch owner to pay for stud fees, costs for chilled semen, transport and monitoring and insemination of the bitch when poor quality semen was used. Bitch owners should insist on such an evaluation in order to avoid disappointment. Failing to do this may also result in planning the entire event and ultimately abandoning the effort because of poor semen. The bitch owner can then run out of time to look for another stud. The evaluation involves semen collection in the presence of a bitch in heat, performing a semen count, evaluate motility and morphology of the semen under a microscope.

Transport of the chilled semen to and from the airport

If at all possible the airport should be Lanseria as there is little traffic and it is close by. If at Lanseria we will fetch and deliver. If Oliver Tambo is required then we advise the client takes care of collection and delivery to the airport or that a courier service is used.

Monitoring of the bitch

The owner of the bitch needs to contact their reproduction vet and inform him/her of their intention to use chilled semen on the bitch. At this stage he can then refer them to a competent vet closest to the stud owner. The owner will then need to present the bitch for monitoring as soon as she comes in season. The heat cycle will be monitored using either vaginoscopy and/or progesterone assays. It is of vital importance that this monitoring process be done correctly. The veterinarian may require daily access to the bitch for up to 9 days. Some owners find this very frustrating but it is important that this process be done correctly according to requirements. The two vets will stay in contact and give prior notice of the date of collection for shipment. This prior notification is usually within 24-48 hours with the intention to collect on the morning of the planned insemination. The aim will be to get the timing accurate enough to do a single insemination, however, some bitches may require a second insemination 24-48 hours later. All this will be communicated with the owner, stud owner and stud’s veterinarian at the time.

What does the owner of the stud do?

Firstly the owners of the stud should establish whether it is possible to collect semen from him and whether his semen is of adequate quality. This examination should preferably be in the week or days ahead of the time that the bitch will be inseminated as collection of semen usually improves semen quality.

As soon as the date for insemination has been established , the owner of the stud and the vet performing the collection will be informed. The semen will then be collected from the stud, ideally using an “in season” bitch as teaser. The semen is then processed and placed in a special container for transport. It must be decided ahead of time how the semen will be delivered to the nearest airport. The most efficient arrangement is for an individual to deliver it to the cargo section, but couriers can also be used. These details should be arranged by the breeders prior to the day of collection. Usually, the bitch owners are able to arrange for collection of the parcel from their airport. If the semen is being collected anywhere away from the major city metropoles, prior note should be taken of flight times from city to city. In some cases, the time of semen collection becomes important, to ensure that the semen makes it onto a flight on time. The package must be delivered to the airport at least an hour before the flight is scheduled to leave. In the cases of major cities, this is not as critical as there are many flights in a day.

The insemination of the bitch

Once the semen has arrived at its destination (which must be the same day that the semen was collected, or at worst, the following day), the semen is inseminated. The insemination can be performed using intra-vaginal insemination, as with fresh semen inseminations. This procedure takes about fifteen minutes. The veterinarian performing the insemination will have to see the bitch for the next few days following the insemination to establish whether another insemination is required. The veterinarian may also decide to inseminate the bitch via trans cervical insemination (TCI) directly into the uterus using an endoscope or surgically implant the semen via a small incision in the abdominal wall. The latter procedure requires anaesthesia and is sometimes frowned upon and indeed in some countries is deemed illegal. Surgical insemination however has the advantage that it may take shorter than a TCI where the operator struggles and during surgical insemination it can be confirmed that all the semen was deposited into the uterus in all cases. Intra uterine insemination either through an endoscope or via small surgical incision is preferred by some specialists.t

Results using chilled semen

The results obtained with chilled semen are less (65-70%) than those of fresh semen (75-85%) provided the bitch and stud exhibit normal fertility. It is important that in the planning of the insemination the veterinarians involved help the breeders with the selection of suitable candidates for this procedure. Clearly a bitch that has not conceived in previous cycles, is not ideal. It is in everyone’s interest that good results are obtained and poor results are minimized by avoiding unsuitable candidates for semen collection and insemination.

Cost estimate of the procedure

The cost for procedures vary depending on practice and area. Therefore breeders wishing to get an estimate should individually contact the vets on the network. (Contact details below)

There are several costs to consider in this procedure. The respective owners must decide who is responsible for which costs. The norm is that the owner of the bitch is responsible for all the costs or that the male owner carries the cost of the initial evaluation of breeding soundness for the stud as suitable donor of semen.

The costs involved are ; Preliminary semen evaluation to establish semen quality and suitability, Semen collection and processing, Cost of transport (Air Cargo), Any courier costs, Cost of the monitoring of the bitch and insemination

 

Who to contact for chilled semen insemination and planning

 

Cape Town:

Dr Rachel Shuttleworth rachelshuttleworth@telkomsa.net

Gauteng:

 Dr Kurt De Cramer kdcramer@mweb.co.za

KZN

Dr Daniella Steckler daniela-steckler@gmx.de

Port Elizabeth

Dr Stephan Ferreira stephan@walmervet.co.za

Clients wishing to use Onderstepoort for chilled semen should contact them directly.

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.