For many trainers around the country, their biggest practical worry from day to day isn't the patchwork quilt of medication rules and regulations, or the fear that one trainer has an unfair competitive edge over another, but whether they've enough grooms, hotwalkers and riders populating their barns to properly tend to the horses in their care. With fewer and fewer North Americans siphoning into horse racing, the sport has turned for relief, of course, with growing reliance on Central and South America--what has proven an increasingly tenuous stable of talent...