The standard way to permanently identify swine is using the Universal Ear Notching System. Pigs are identified within a week of birth by making tiny triangle shaped notches in their ears. These notches will continue to grow with the pig. The right ear is used to identify the litter, meaning all pigs in the same litter will have the same notches in the right ear. The left ear identifies the individual pig. For example, in a litter of six pigs, the piglets will have 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6. You’ll notice that the placement of the notch indicates what number that notch adds to the total.
Reading ear notches takes a lot of time and a ton of practice, but you can be an expert in no time if you try! Check out this University of Minnesota Extension video to see examples!