A brief note about breeds, the breeds listed on this site are not a complete list of oxen breeds.  Any breed of bovine can be trained as oxen, although dairy breeds tend to be more temperamentally suited for close work with humans.  Beginners should consider easygoing dairy breeds, while more advanced trainers may wish for a more high spirited and faster moving, or more muscular breed.  Oxen: A Teamster’s Guide to Raising, Training, Driving & Showing includes an overview of the popular oxen breeds.