Pedigree analyst Avalyn Hunter discusses the debate over artificial insemination use in Thoroughbreds.

The debate over whether to permit artificial insemination (AI) in the Thoroughbred has been around just about as long as the practice, which was first studied seriously in the late 1800s as an alternate to natural breeding. To date, all major Thoroughbred registries ban foals conceived by AI, along with those produced by embryo transfer and other assisted reproduction techniques.

The latest challenge, a suit filed in Australia by owner-breeder Bruce McHugh on the grounds that the requirement for natural service constituted an unlawful restraint of trade, was denied in a Dec. 19 court decision rendered by Justice Alan Robertson. Had the ruling gone otherwise, Thoroughbred regulatory bodies around the world now would be faced with the issue of whether to open their own registries and racing to AI-sired animals or to ban Australian horses so begotten–no light consideration, given that Australia is the second largest Thoroughbred breeding market behind the United States.

Many arguments have been advanced for and against AI based on considerations such as safety, boarding expenses, the potential for spread of diseases and genetic disorders, and potential effects on stud fees. But from a pedigree perspective, the main argument boils down to genetic diversity. And even there, opinions are mixed