Sexing mammalian sperm--intertwining of commerce, technology, and biology.

Sperm from many mammalian species can be sexed by flow cytometry/cell sorting at about 90% accuracy without damaging them unduly. However, because sperm are evaluated one at a time, in series, the number of sexed sperm produced per unit time is limited. Furthermore, the equipment required currently is expensive, in the order of 300,000 US dollars per machine. Despite these limitations, commercialization of this technology has begun with bovine semen, in part by inseminating cattle with relatively low number of sperms. No other approach to sexing sperm in any practical way is likely to be available within the next few years. The constraints for commercial application of sexed sperm in cattle can be somewhat lowered fertility, the high costs of equipment and skilled personnel, and costs of intellectual property such as licensing fees and royalty payments. Most economic analyses indicate that farmers can afford to pay 10-20 US dollars more per dose of sexed sperm than unsexed sperm if costs must be recouped by selling milk or meat. When the product is breeding stock or for certain niche applications, a higher price for sexed semen may be justified. Sexed sperm will be used more broadly in cattle only when improved production and/or efficiency can compensate for the extra costs of purchasing sexed sperm.