Stallion – Epididymal Sperm

Epididymal sperm, or sperm located in the epididymis is able to be salvaged at the time of castration and frozen for future use, however studies have shown that it is not as fertile as ejaculated sperm.
Stallion epididymal sperm has been shown to display motility lower than ejaculated sperm, with the lack of exposure to seminal plasma and other factors at the time of ejaculation being thought to be responsible for this lower motility and subsequent poor fertility.

This technique is invaluable if your stallion unexpectedly passes, as it enables you to preserve genetics that would other wise be lost. It is important however to understand that this technique does not yield results seen with ejaculated fresh and frozen semen, and therefore we would recommend collecting and storing frozen ejaculated semen if you are serious about breeding with the semen in the future and as insurance against loss of your stallion.

On going research will hopefully increase our understanding of the factors epididymal sperm are exposed to upon ejaculation and how this can be applied/imitated to increase its successful use in breeding programs.