Dr. Mennick first learned the techniques involved with these species in Australia, spending time at both Maquarie Artificial Breeders in Dubbo, and Riverina Artificial Breeders outside Albury. Dr. Greg McCann at Maquarie, in fact, was one of the five originators of the laparoscopic AI procedure, and at the time inseminated roughly 100,000 ewes per year using this technique. He later learned a few additional details at Ambreed's South Island breeding center in New Zealand. In both countries, sheep far outnumber humans, and the use of frozen semen from top sires is far more widespread in breeding programs than it is here in North America.

At the time, semen was commonly frozen in "pellets" on dry ice blocks before submersion in liquid nitrogen and packaging of the pellets in plastic goblets. Many technicians overseas still feel this method of processing makes a superior product compared to freezing in straws. However, the straw method of packaging is now required for International shipments, and the potential of "spilled goblets" during handling (individual pellets, of course, cannot be labelled) was always a concern. Depending upon the owner's plans for the semen we preserve, we can process either in straws or pellets.

Bucks take a little extra work in processing, mainly to determine whether or not their semen contains an enzyme that has the annoying side-effect of coagulating the egg yolk normally required in all semen freezing media to protect the sperm cells. This situation appears to be somewhat breed-specific, but each sire must be checked for its presence. If this enzyme is present, we must first "wash" the sperm multiple times to eliminate this enzyme before completing the cryopreservation process.

Because the sheep cervix is so convoluted and narrow, vaginal insemination typically gives poor pregnancy rates with frozen semen. A natural question is, "why then, is the ram so much better at it?" The answer primarily has to do with sheer numbers in the insemination dose. The ram, generous as he is, typically delivers 2 or 3 billion sperm outside the cervix, with only a small percentage of those making it all the way through. Frozen semen, to make efficient and economical use of each collection, divides this dose perhaps hundreds of times, and thus one resulting dose has too few sperm to complete the task. A technique using a special catheter has been developed for intracervical insemination using frozen semen doses, which does improve pregnancy rates somewhat, but it is very difficult to perform properly and requires significant practice. The best results, typically 100 to 130% lambing rates in white-face ewes (black-face ewes half that), is by surgical insemination; a quick injection of the small dose directly into the uterine lumen. This makes most efficient use of valuable semen, because the insemination procedure is quick and relatively inexpensive. With this method, typical insemination doses of 20 to 60 million sperm are quite successful.

The doe's cervix is not so tortuous as the ewe's, and so vaginal insemination with frozen semen is more successful, utilizing a special, stiff-tipped pipette.