Ordering cooled equine semen can involve considerable costs. Customers should expect high quality of the insemination dose for optimal fertility. A study conducted by researchers from the University of Veterinary Medicine, Vienna, took a closer look. The team examined insemination doses shipped from various EU semen collection centers:
"We hypothesized that suboptimal pregnancy rates in equine AI may primarily result from breeding with low quality semen not adequately processed for shipment. ... Thus semen quality at the time of insemination rather than at the time of processing directly after collection was taken into account."
The researches found that "Stallion semen processing is far from standardized and differs substantially between AI centers." Less than half of the doses were in the optimal concentration range for insemination (25-50 million sperm per ml). Less than 20% of doses were in the optimal temperature range for cooled-shipped semen (4-6 °C) (Heckenbichler et al., 2011).
Storing semen at suboptimal temperatures can have a detrimental effect on the quality of the semen, especially if it is not used within 30 hours.