Universal Ear Notching System
Each ear is divided into four parts; Each area representing the numbers: 1, 3, 9 or 27; In each of the four areas, you can have up to 2 notches.
The right ear is used for litter mark. All pigs in the same litter must have the same notches in the right ear.
The left ear identifies individual pigs in the same litter. All littermates must have different notches in the left ear.
No more than two notches may be made at any position. When those positions are filled in the right ear, an 81-notch placed in the tip doubles the system. Only one notch may be at the 81 position.
January 1 and July 1 of each year are the starts of each farrowing season. The first litters born in each of these seasons should be notched litter #1.