The use of assisted reproductive technologies is prohibited in the Thoroughbred industry. Historically this has meant that stallion sperm quality cannot be thoroughly assessed prior to breeding the mare. The determination of putative stallion fertility at the time of cover would allow managers to make informed decisions about strategic breeding practices, such as cross covering or alterations in booking schedules, in a timely manner. The major objective of this investment is to produce a commercially available device to measure the metabolic rate of spermatozoa in a post breeding 'dismount' semen sample to identify samples which are unlikely to produce a pregnancy. This will allow stallion managers to schedule a mare to be rebred on the same cycle to increase the chance of a positive pregnancy outcome.