Swine Identification

by Lori Meads, Educator

As humans, we are all identified by a number, the most common being our Social Security Number. Swine, too, are identified by a number; the system of identifying them is based on either ear notching or ear tagging. Each method provides a way of tracing an animal back to the farm where it is housed.

HOG YARD, undated. Chowan County

Courtesy of the Chowan County Arts Council

Ear notching is the oldest form of identification for swine. Notching provides a permanent way of identifying individual animals - and it’s inexpensive. Notching the ears of swine needs to occur within a week of birth.

The notching process is completed by placing notches in the left and right (as viewed from the rear) ears. The right ear has five locations for notches, but is divided into four quadrants; each of the four quadrants has a value (1, 3, 9, 27) and may have one or two notches, with a central notch always identified as 81. These notches are added together to determine the litter number. The left ear is divided into four quadrants with three locations for notches. The assigned number values on this ear are 1, 3, and 9. All notches, based on their locations, are added together to identify the hog’s birth order.

Ear tags are also a common method of identifying swine, especially in large operations. One of two “840 ear tag” systems (visual or electronic) are utilized by many farms. The number on each tag is fifteen digits long, with 840 (the numerical code for the US) being the first three and the other 12 being unique to an animal. The tag is placed in a hog’s ear, much like an ear piercing.

The next time you see a sounder of swine, check out their ears and see that they are providing you with their identification.