With an unusually high capacity for transmitting his best qualities though carefully selected crosses, Welsh are often used to improve performance lines.  The Welara (Welsh x Arabian) and the American Walking Pony (Welsh x Tennessee Walking Horse) registries were formed using Welsh bloodlines.  Many historians believe that Justin Morgan, the founding sire of the Morgan breed, was sired by a Welsh Cob left behind by British soldiers after the Revolutionary War. 

Half-Welsh Registration requires one purebred registered parent while Part-Bred Registration requires one registered Half-Welsh parent.