Collection and freezing of equine epididymal spermatozoa

The epididymis and vas deferens store an important number of fertile spermatozoa called the extragonadal sperm reserves. These stored spermatozoa can be collected in an ultimate attempt to preserve viable spermatozoa of a critically ill or dying stallion. Epididymides are collected via routine castration. After cooled transport of the testicles and epididymides, spermatozoa are collected either by retrograde flushing or by the float-up method. Retrograde flushing usually results in a much higher sperm yield and is considered the method of choice. Epididymal spermatozoa can be frozen using standard freezing protocols.