Universal ear notching system for pigs
Purebred swine breeders are required to ear notch pigs to be eligible for registration in their respective swine breed associations. There are several different ear notching systems in use which tend to be confusing not only to breeders, but also to testing stations, extension works, vocational agriculture instructions, and others who work with swine exhibitions and improvement and selection programs.
Archive version. For most recent information see extension.missouri.edu.