What started as a tragic story Down Under ended happily when a dressage-caliber female horse “adopted” a newborn colt abandoned by its own mom. In Victoria, Australia, last November, a gorgeous Dutch warmblood named Jazzabelle (or Jazzy) bore a stillborn calf to Melbourne-based breeder Sarah Brayshaw, who was subsequently crestfallen by the ill-fated birth. Brayshaw…