Oviductal insemination of mares.

A technique was developed for oviductal insemination of mares, in which a small number of motile spermatozoa are deposited directly into the oviduct. Pregnancy rates in mares inseminated by traditional intrauterine artificial insemination were compared with rates in mares inseminated by oviductal insemination. Fifteen mares were inseminated with 5 x 10(8) progressively motile spermatozoa by intrauterine artificial insemination, and 14 mares were inseminated with 5 x 10(4) progressively motile spermatozoa by oviductal insemination. Pregnancy rates in mares inseminated by intrauterine artificial insemination (40%) and oviductal insemination (21.4%) were not significantly different (P > 0.05). This study indicates that oviductal insemination can produce pregnancies in mares using 10,000 times fewer spermatozoa than are used for intrauterine artificial insemination.