For what? A heifer should be at least 2 years old before breeding. Any kind of performance horse should not be started til it is 4, and should not be entered into competition before 5 yrs old. There is absolutely zero difference in the modern 21st century TB racing horses, ad those 50, 100, even 20 years ago. Times are virtually the same. Records have remained unbroken for as long, for some, and when they are broken, they are in fractions of a second. TB's were developed in England in the 16th and 17th centuries, and perfected i9n the 18th century. Where as, say human athletes, which have NOT been selectively bred for performance, are continually setting and breaking and re-setting performance records. There is no
epidemic" or "escalation" of racing-related TB deaths... you just hear about them more and sooner because of the social media age we live in. There is no escalation of using performance enchancing drugs in TB racing either...there is just better and more frequent testing for them. It is ludicrous to suggest that breeders are breeding for fragile, light weight bone structure. A colt or filly either one, no matter what they cost, is put down . Even if you could tray to keep one alive and healthy to breed, no one would breed to that colt or buy a foal out of that filly, because it broke down.