As breeding season is coming to a close, many of you may be wondering what you should do about unused doses of frozen semen that remain in the possession of your mare owners and what you should do with returned semen. Stallion owners often express concern that if frozen semen is sold as part of a breeding contract, unused doses of semen remaining after the original mare becomes pregnant may be sold to a 3rd party or used to inseminate another mare without payment of any additional stud fees. But, if frozen semen is returned, how can you know if the semen quality has been compromised and what should you do with it? Here we offer some advice on how to minimize the amount of unused frozen semen that is outstanding at the end of the breeding season and how to handle the fate of this frozen semen in your breeding contracts and if it gets returned.