Complex sentence: The breed was also used to create and improve the Holstein and Hanoverian breeds, as well as the short-lived Yorkshire Coach Horse, an official breed that was a cross between the Cleveland Bay and the Thoroughbred, and the Vladimir Heavy Draft.
Split into simpler sentences: The breed was also used to create and improve the Holstein and Hanoverian breeds. They were also used to create the short-lived Yorkshire Coach Horse, an official breed that was a cross between the Cleveland Bay and the Thoroughbred, and the Vladimir Heavy Draft.