The 21st Century has seen the advent of a wide variety of reproductive technologies for the human population, and veterinary technology is not lagging too far behind. Artificial insemination and embryonic surrogacy have been widely available to horse breeders for the last decade, and the cloning of several carefully chosen equines, including the legendary jumper Gem Twist, have proved successful. As a society we continue to push the boundaries of what can be accomplished by tweaking or manipulating fertility and reproduction, and as we continue to renegotiate our normal assumptions about how and when horses can be bred, unique ethical queries will undoubtedly arise.
Case in point, the AQHA Journal's recent article detailing the sexual selection efforts underway at Moondrift Farm in Ft. Collins, CO. Here horses are being bred selectively for gender, through a technique that allows X-and-Y-bearing sperm to be separated and utilized on demand. The operation estimates that it can guarantee gender in its program's foals with a %93 percent degree of accuracy, making this technology seem a relatively sure bet in terms of veterinary efficacy.
What are the ramifications of breeding for one gender or another? I can see this question coming into play acutely in industries where show horses are the main focal point, as winning stallions can go on to have more lucrative breeding careers than mares. Should that mentality result in an overselection for male foals, the consequent flooding of the market with stallions of the same bloodline could lead to those same stallions becoming devalued. Along those lines comes the risk, also addressed by the article, of overconcentrating one breed's genetic pool, and perpetuating genetic weaknesses. There is also the potential, as the article points out, of furthering the transmission of genetic diseases that are passed down via an X or Y chromosome. Perhaps this risk could be negated through standardized genetic testing, but that testing assumes that we know which diseases to test for.
What other pros and cons might exist for a breeder who opts to select their numbers of fillies and colts? How might this change breeding strategy, and the dynamics of the breeding industries at large?