Uh oh! There’s blood in the sperm collection. Is the semen still usable?

A stallion can have blood in his sperm (called hemospermia) from any number of causes, from a simple laceration to more serious scenarios, such as carcinoma (a type of cancer). Practitioners know that blood in the ejaculate is associated with subfertility, but does that mean you have to discard every collection tinged with blood?

At the 2016 American Association of Equine Practitioners Conference, held Dec. 3-7 in Orlando, Florida, Carly E. Turner, DVM, Dipl. ACT, presented the results of research performed at Texas A&M University that addresses this question. The researchers hypothesized that fertility would decrease as the amount of blood in the ejaculate increased. But how much blood is too much?

The researchers collected sperm from a 26-year-old Quarter Horse stallion in an artificial vagina. They evaluated each ejaculate for total sperm number, viability, and motility and divided it so that, eventually, each mare would be inseminated with the same number of sperm