What does knowing the ovulation day do for us?
It tells us when the eggs will be fertile, which is important with all breedings, but especially so with fresh chilled extended semen and with frozen semen. Once ovulated, a bitch's eggs take approximately 48 hours to become fertile. They will then remain fertile for approximately 48 hours. The idea is to maximize contact time between viable semen and fertile eggs. This requires a brief discussion on semen longevity.
Fresh semen can remain fertile in the bitch's uterus for 3-5 days and in some cases even longer, depending on quality. Fresh chilled semen, because of energy lost in the cooling and subsequent warming process, may live only 24-48 hours in the uterus.
Frozen semen, due to the stress of the freezing process and energy lost, may live only 12-24 hours in the uterus. Clearly, the shorter the sperm's life span, the more paramount it becomes to know when it should be inseminated to allow for maxi mum contact time with fertile eggs. In the case of fresh semen, there is more flexibility for two reasons. First, there is usually not a limited quantity, and second, it lives a long time. We routinely recommend breeding days 1 and 3 or days 2 and 4 post ovulation with fresh semen, though one breeding is usually sufficient. With fresh chilled extended semen, because of a 24-48 hour life span, we recommend breeding 2 days after ovulation.
Improving fertility in males
Semen requirements for a pregnancy and large litter size large numbers of high quality semen are needed. Studies show that repeated matings with large amounts of semen produces more pups than single matings with small amounts of semen.
Frozen semen inseminations need 100 million live motile sperm. Natural matings will supply 200 – 1000 million sperm depending on the size of the dog. Fresh semen can live for 7 – 10 days inside the bitch. Chilled semen can live for 2 - 4 days. Frozen semen can live for 1 – 48 hours Normal sperm Normal sperm consists of a head which carries DNA (the genetic material) and a tail which is used to propel the semen along.
The first recorded artificial insemination in dogs was done by a researcher named Spallanzani in Italy around 1780. So much for Ancient History. More recently the early experiments using thawed frozen semen for artificial insemination met with poor success rates - mainly due to the fact that the technology carried over from other species did not adapt well to dogs.
However in the last thirty years dramatic improvements have been made as researchers have identified and solved the problems associated with storing canine semen and getting ovulation timing right.
Todays experienced practitioners in this field achieve conception rates that are far superior in numbers to anything reached in the past.