Each batch of semen that we supply comes with a Post-thaw analysis test result. Basically this means that after freezing, two straws from each batch are thawed and analysed. Any batch that does not reach the required standard is destroyed , leaving only good semen. These post thaw results accompany the semen and when the vet inseminates your mare he analyses the semen to make sure it compares with the test results. That way we know the semen has been handled properly and is in perfect condition when it enters your mare.
Frozen semen is stored and transported in liquid nitrogen tanks.
This keeps the semen at a temperature of 196 degrees centigrade. If the temperature rises above this level for more than ten seconds serious damage will occur to the semen. Great care is required when transferring the semen between tanks. They have not been freezing semen long enough to say that it will not keep. We have put mares in foal with semen that was frozen 18 years ago and in Germany they have a horse that was conceived with semen that was frozen 23 years before.