Identify Pigs by Ear Notching

Guide B-602

Revised by Craig Painter and Jason L. Turner

College of Agricultural, Consumer and Environmental Sciences, New Mexico State University

Respectively, Extension State 4-H Agent for Agriculture and Natural Resources; and Extension Horse Specialist, Department of Extension Animal Sciences and Natural Resources, New Mexico State University. (Print Friendly PDF)

An accurate set of records on swine performance is one of the best management tools a producer can have. In order to keep such records, producers must be able to identify pigs from birth.

The successful manager clips the needle teeth and navel cords as soon after birth as possible. This also offers an opportune time for identification. The simplest method and the one recommended by most breed associations is ear notching. The most common notching system is the 1-3-9 system. For piglets of this size, a small (3/16- to 1/4-inch-deep) V-notcher is recommended (Figure 1). If this is your first time ear notching pigs, consult your county Extension agent ( or an experienced swine producer in your area for assistance to help you develop this skill.

Figure 1: Photograph showing a V-notcher and a piglet’s ear being notched.

Figure 1: Photograph showing a V-notcher and a piglet’s ear being notched.

Figure 1. A V-notcher (top) used to notch the ears of small piglets for identification (bottom). (Photos courtesy of Craig Painter.)

Litter Mark: The right ear is used for the litter mark, and all pigs in the same litter must have the same notches in this ear. The right ear is on the pig’s own right. The litter mark ear is divided into five sections, and each section has a numerical value, either 1, 3, 9, 27, or 81 (Figure 2). Each section, except for 81, can have 1 or 2 notches only.

Individual Pig Marks: The left ear is used for notches to show an individual pig’s number in the litter. Each pig will have different notches in the left ear. The left ear is divided into three sections, with values of 1, 3, and 9 (Figure 2).

Figure 2: Illustration showing numerical values for different ear notch sections in the 1-3-9 system.

Figure 2. Numerical values for different ear notch sections in the 1-3-9 system. The hatched area represents the area where notches should not be placed to avoid confusing #1 with #3, etc. (Drawing courtesy of Craig Painter, modified by Sue Miller.)

To develop a number, make notches in different parts of the ear in such a way that their numerical values will add up to the desired number. For proper identification to be made, it is essential that the notches be placed in the appropriate area of the ear so that the mark is clearly a 1 versus a 3, or a 9 versus a 27.

Figure 1 shows the proper technique for using a V-notcher. Figure 3 provides examples of ear notches using the 1-3-9 system, and Figure 4 provides examples to help you practice using ear notches.

Figure 3: Illustrations of examples of litter and individual pig ear notch numbers.

Figure 3. Examples of litter (left number; right pig ear when viewed from behind the pig) and individual pig (right number; left pig ear when viewed from behind the pig) ear notch numbers. (Drawing courtesy of Craig Painter, modified by Sue Miller.)

Figure 4: Illustrations of un-notched ears to be used for src=

Figure 4. Practice examples: For the illustrations, draw in the marks that represent the numbers indicated below each pig’s face.

For Further Reading

M-114: Nitrate in Drinking Water

H-149: Marketing Alternatives for Small- to Medium-sized Family Farms and Ranches

CR-477: Small Poultry Flock Management

Original authors: L. Neil Burcham, Extension Swine Specialist; and Jason L. Turner, Extension Horse Specialist.

Photo of Craig Painter.

Craig Painter is an Associate Professor and Extension State 4-H Agent for agriculture and natural resources with NMSU’s Cooperative Extension Service. He earned his master’s degree from New Mexico State University in agriculture and Extension education.

Photo of Jason L. Turner.

Jason L. Turner is Associate Professor and Extension Horse Specialist. Jason was active in 4-H and FFA while growing up in Northeastern Oklahoma. His M.S. and Ph.D. studies concentrated on equine reproduction, health, and management. His Extension programs focus on proper care and management of the horse for youth and adults.

To find more resources for your business, home, or family, visit the College of Agricultural, Consumer and Environmental Sciences on the World Wide Web at

Contents of publications may be freely reproduced, with an appropriate citation, for educational purposes. All other rights reserved. For permission to use publications for other purposes, contact or the authors listed on the publication.

New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating.

July 2019 Las Cruces, NM