Storing Frozen semen

Guide dog schools may wish to use frozen semen from another guide dog school or breeding colony that has been practicing selective breeding for many generations. See Sections 2 and 3 for more details.

To effectively use frozen semen, the recipient school must be able to properly store frozen semen and be able to successfully handle, thaw, and inseminate with it. The excel document in the CD TCI Equipment0506 provides a listing of the equipment needed and its cost in US dollars at that time.

Maintenance of the semen storage tank is vital. Semen is normally stored in special tanks that are filled with liquid nitrogen. As liquid nitrogen evaporates over time, it is necessary to replenish the tanks with small amounts weekly. The liquid nitrogen has to be replenished about once a week. Normally, companies selling various gases to hospitals or welding companies will deliver liquid nitrogen.

It is imperative to never let the storage tank run low or out of liquid nitrogen or else the semen will be ruined. On a weekly basis, measure the LN2 level in the tank with a yard/meter stick. Be alert to a significant change in the amount of liquid nitrogen. If it drops dramatically, this is an indicator that the tank may be failing. Tanks need to be replaced about every fifteen years, although tank failures due to cracks from defects or mishandling can shorten the tank life. In addition to measuring weekly, almost daily checks should be performed by observing the outer tank for evidence of frost. If a tank is operating correctly, the exterior should be at ambient temperature (NOT cold), with no frost present. Some tanks can be equipped with temperature sensors for additional cost.