Artificial insemination (AI) is used widely in the horse industry. The success of frozen semen AI in the horse is limited by the variability in fertility of stallion semen after freezing and thawing. Conception rates using fresh chilled semen can be as high as those of natural service. However, the longevity of fresh chilled semen is limited (usually 24 – 48 hrs).
A bovine semen extender has been developed that prolongs sperm life for 3-4 days when maintained at ambient temperature. This report presents the results of a study into the use of this extender with horse semen.