Semen is collected by manual stimulation of the dog. We get a much better sample to freeze when a “teaser” bitch in season is present. We encourage you to talk to your friends with intact bitches and borrow one when she is “prime”, at about 7-10 days into her estrous cycle, to be used as an incentive for your male!
The semen is then examined for motility as well as morphology, which is the quality of the semen as far as percentages of normal and abnormal sperm. We like to have semen that is as least 80% normal sperm to freeze as we will lose some of it during the freezing process. Good quality semen, going into the process, is a MUST if we are going to get good quality frozen semen to inseminate years later.
Extension and chilling
The semen is then spun in a centrifuge to separate out the semen from any prostatic fluid as we want to only freeze the semen portion of the collection. The semen is then mixed with an extender, which is a solution that contains nutrients, antibiotics, buffers and protectants to help stabilize the sperm cell membranes during cryopreservation. The mixture is then refrigerated to slowly start cooling down the semen.
Straws/Pellets made and frozen in liquid nitrogen
The chilled semen is then either loaded into straws, which are thin plastic tubes, or made into pellets, which are single drop-sized “dots” made in dry ice and stored in a cryo-vial. Each straw/cryo-vail is labeled for identification with the dog’s name, AKC number, DNA number, date, owner’s name and breed. These are immersed in liquid nitrogen, which is about -320°F and stored until needed.
Thaw evaluation test
After freezing, either 1 straw or 1 pellet is then thawed in a water bath at body temperature and the semen is then evaluated under a microscope to see what percentage of good quality semen survived the freezing process. This then allows us to calculate how many pellets or straws will be needed to give us a “breeding unit”, or calculated amount of semen needed to breed 1 bitch.