The initial contact when planning a frozen semen litter has to be with a very co-operative stud dog owner. Then comes the collecting veterinarian, all the requisite paperwork for Government Permits, Canine Controlling Body, and veterinary certification in both countries, co-ordinating all the blood tests (some are before collection on the stud dog and others are before insemination on the bitch), organising the shipping in one country and the collection in the other, and finally total confidence in the ve terinarian doing the insemination. When ours says "ready" we GO, no matter what our own instincts are about the timing.
One of my friends in another breed who has produced many litters from frozen semen sums it up best .... "First you need the budget for a large phone bill, second an understanding and very talented veterinarian, and third - nerves of steel.!"
The old rule for using frozen semen used to be only to select a proven dam with a "normal" well documented ovulation pattern and to expect half an average litter size. Nowadays many maiden bitches in many breeds are being successfully inseminated and prod ucing breed-typical sized litters, as was the case with our 1993 insemination which produced nine puppies.
In addition to the three litters since 1992 we now have one from American semen stored for only a few months. We have also had three FAILURES. One of the sires subsequently produced the 1995 puppy from a different dam. The other has been used twice, on tw o different bitches, without success, yet his semen on post thaw examination is of higher quality than that of the others with whom we have succeeded. Both the bitches this semen was used on were already proven dams so there is no obvious reason why to da te his semen has failed to produce puppies.
Although there are many failures, the success rate is increasing all the time. Nowadays our vet is averaging an 80% success rate, mostly by surgical insemination. In 1979, the average was 40%.
Newer techniques are being introduced and perfected. Numerous progesterone levels via blood tests, or daily vaginal smears are taken so that the most accurate assessment can be made as to when to inseminate. Modern day "packaging" of frozen semen is vast ly advanced, in the way of diluents and the provision of buffering solutions to alleviate shock and travel damage.Used only in extreme circumstances in surgical inseminations because the increased volume of fluid may be detrimental, a "waker upper" post t haw buffer is now sometimes used to activate sperm prior to insemination by other methods, for example with fibre optic trans cervical insemintion.
All this progress makes the fact that we obtained puppies in 1976 even more important, because we were all - breeders and veterinarians alike - "flying by the seat of our pants".
It would be interesting - but extremely difficult for the many obvious reasons - for someone to do the statistics on how many natural matings fail as well, but as thawed semen lives for less than one day - some research indicates in fact only a twelve hou r lifespan - and fresh semen lives for three to five days or sometimes more, it is obvious that the timing with frozen semen is extremely crucial.
The most crucial factor is the timing of the individual bitch's ovulation pattern and this in an area in which great advances have been made in recent years.This varies from bitch to bitch and can also vary from season to season in the individual, althoug h another Australian breeder who has been enormously successful with using frozen semen told me that on one occasion he made a last minute decision and simply went by the timing for the bitch's previous A.I. litter, getting a satisfactory number of puppie s without doing any further progesterone levels.
Our vet commences blood tests around the third day and continues every forty eight hours with two, three, four or even more tests depending on how the progesterone levels are developing. Other vets do daily tests using different procedues.
The canine is the only species in which the eggs divide and multiply after ovulation, and therefore surgical inseminations are usually performed several days LATER than when a bitch first indicates she is prepared to stand for a dog, in order to maximise the number of eggs available for fertilisation. Thawed sperm used for surgical implant do not have to undergo the final development stage known as capacitation, which is required of fresh sperm which have to swim to the ova over a period of time. Not all bitches multiply their ova all at the one time, and it is those bitches who do this sequentially for whom it is the most difficult to accurately predict the optimum time for insemination.
Because with surgical insemination the semen in implanted directly, puppies are usually born earlier than 63 days, ours have all been around the 57/58th day, and fully viable.
Many bitches whelp completely naturally but for some reason, it seems that many who have been inseminated with frozen semen do not, so be prepared that a caesarean may be necessary. This is important and breeders need to watch their bitches very closely, especially if only one or two pups have been conceived, as signs of labour are then always very slight, and often a caesar is necessary in this situation even from a natural mating, because labour is triggered by the first pup lining up to be born, with t he others queuing up behind, and with a single pup the bitch very often just does not get the message to go into labour.
Do NOT expect a text book 63 day gestation period if you have used frozen semen, especially by surgical insemination. We exported semen to England a few years ago and the skilled inseminating veterinarian achieved a succesful pregnancy. Tragically however nine puppies were born dead, because the owner had moved from the area and had to consult a local veterinarian who was not experienced with frozen semen. He would not accept this information of a shorter but fully viable gestation period when it was conv eyed to him, and insisted on waiting out not only the average 63 days, but actually let the poor bitch go to her 67th day before deciding to do a caesar as she showed no sign of going into labour. Decomposition of the puppies was of course well advanced, the bitch was by then highly toxic, and has never conceived since despite several natural matings.
We ultrasound to confirm the pregnancy and our veterinarian checks our bitches about the 55th day and x-rays if he deems it necessary, so as to be certain how many puppies to expect. He then decides when they should whelp, based on the technical information gained from the progesterone level tests formerly conducted and of course the date of the insemination. So far he has 100% success rate with his projected whelping date.
Wendye Slatyer July 97
Copyright(c) 1997
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