Many advances have been made in the assisted reproduction for horses in recent years. Artificial insemination is a widely practised breeding method in most sport horse breeds and most countries. This has resulted in such terms as “mail order” semen and “sexed” semen. More advanced technologies such as Intra Cytoplasmic Sperm Injection (ICSI), Deep Uterine Insemination (DUI) with low dose inseminations are more recent techniques.

We have observed that the quality of the sperm is very varying from stallion to stallion and this presents a problem to breeders and veterinarians around the world. And we know that some specific stallions are valuable even though they have bad sperm quality. By separating the sperm through a density gradient prior to freezing, inseminating, or sexing the semen, we can not only eliminate all the bad quality spermatozoa and therefore decrease the size of the insemination doses but also remove reactive oxygen species, most bacteria and many viruses. This significantly increases the survival and therefore the fertilising potential of the sperm.