Swine Ear Notching Laws in Colorado: What Pig Owners Need to Know
September 4, 2026
If you raise pigs in Colorado — whether on a small hobby farm along the Front Range or a larger purebred operation on the Eastern Plains — understanding swine ear notching rules is not optional. Ear notching is one of the oldest forms of livestock identification, but its legal standing in Colorado depends on very specific conditions that trip up producers who assume a notch is always enough.
This guide walks you through when ear notching qualifies as official identification under Colorado and federal rules, how the universal notching system works in practice, what purebred registry compliance looks like, and how notching stacks up against newer methods like RFID tags and tattoos. Whether you are preparing for your first litter or moving breeding stock across state lines, the information below will help you stay compliant and avoid costly delays.
What Is Swine Ear Notching and When It Is Used in Colorado
Ear notching is a permanent identification method that involves cutting small V-shaped notches into specific positions on a pig’s ears. Ear notching is widely used in the swine industry as a system of animal identification, with all systems identifying a pig by litter number and individual pig number. Because the notches are made directly in the cartilage, they remain readable for the life of the animal — no tag to lose, no ink to fade.
In Colorado, ear notching is used in three main contexts: purebred breeding operations that register animals with a breed association, 4-H and FFA exhibition pigs, and small-scale farms that want a low-cost permanent record system. Ear notching can also be used in other animal species, but it is not utilized as widely as it is in the swine industry. For Colorado pig owners, the key question is not whether you can notch — it is whether that notch satisfies the state’s official identification requirement for the purpose at hand.
Colorado classifies swine as livestock under state law. Livestock means cattle, horses, mules, burros, sheep, poultry, swine, llama, cervids, bison, and goats, regardless of use. That classification means swine are subject to the Colorado Department of Agriculture’s Animal Health Division rules on identification, movement, and import — and ear notching fits into that framework only under defined circumstances.
Pro Tip: Contact the Colorado Department of Agriculture Animal Health Division at 303-869-9130 or animalhealth@state.co.us before moving swine across county or state lines to confirm which identification method is required for your specific situation.
When Ear Notching Qualifies as Official Identification in Colorado
Not every notched pig carries official identification. Colorado’s rules mirror the federal standard set by USDA APHIS, which is clear about this distinction. Ear notching qualifies as official identification if the ear notching has been recorded in the book of record of a purebred registry association. Without that registry record, the notch is a farm management tool — useful, but not legally sufficient for movement or import documentation.
The Colorado Department of Agriculture’s swine page lists the forms of official identification accepted for swine entering the state. Official identification required includes an 840 RFID tag, silver “brite” tag, breed registration tattoo with breed registration papers accompanying the CVI to the state office, microchip, or registered ear notch. The phrase “registered ear notch” is the operative language — the notch must be on file with a recognized breed registry to count.
Commercial swine moved into Colorado under a current Swine Production Health Plan may be exempt from CVI and Official Identification requirements. This exemption applies to large commercial operations with an approved health plan in place — it does not extend to backyard pigs, exhibition animals, or purebred breeding stock moving between farms.
Under federal interstate commerce rules at 9 CFR § 71.19, no swine may be sold, transported, received for transportation, or offered for sale or transportation in interstate commerce unless each swine is identified at whichever of the following comes first: the point of first commingling with swine from any other source, upon unloading at any livestock market, upon transfer of ownership, or upon arrival at their final destination. If your registered ear notch is on file with a breed association and the registration papers travel with the animal, that notch satisfies this federal requirement.
How the 1-3-9 Ear Notching System Works
The standard used by purebred swine associations across the United States — and the system you will need to use if you want a registered ear notch to count as official ID in Colorado — is the Universal Ear Notching System. It is sometimes called the 1-3-9 system because of the numerical values assigned to each position on the ear.
The universal ear notching system is based on the fact that a pig has two ears. The pig’s right ear, as viewed from the rear of the pig, is designated as the “litter” ear. All pigs born to the same sow have the same litter number and thus identical notches in the right ear. The pig’s left ear designates the pig number within the litter, with the first piglet assigned pig number one, the second piglet pig number two, and so on.
Each ear is divided into four quadrants, with each quadrant representing a number. The outside bottom quadrant represents the number 1 — if there are two notches in that quadrant, the number is 1+1 or 2. There will never be more than two notches in any quadrant. The outside top quadrant represents the number 3, and the inside top quadrant represents the number 9. In the litter ear only, the inside bottom represents the number 27.
The notch in the very tip of the right ear signifies litter number 81. By utilizing the “81” notch, you can identify up to 161 distinct litters using this system. For a practical example: to notch litter number 7, you would place two notches in the outside top quadrant plus one notch in the outside bottom quadrant of the right ear (3+3+1 = 7).
Key Insight: The notching must be done at or shortly after birth — typically within the first few days of life — while the cartilage is soft and the piglet is small enough to handle easily. Using a sharp, clean ear notcher and disinfecting between animals reduces infection risk and keeps notches readable.
The right ear is used for the litter mark, and 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, and all littermates must have different notches in the left ear. No more than two notches may be made at any position. These rules come directly from Certified Pedigreed Swine, one of the purebred registry associations whose records can support official identification status.
Penn State Extension’s swine identification course provides detailed diagrams of the universal system and is a reliable reference when you are learning to apply and read notches accurately.
Ear Notching for Purebred Registry Compliance in Colorado
If you raise registered purebred pigs — Duroc, Hampshire, Yorkshire, Berkshire, or any other recognized breed — ear notching is the traditional identification method tied directly to your breed association’s registration process. The notch you apply at birth becomes the permanent record that links the pig to its registration certificate.
Under both USDA APHIS rules and Colorado’s import requirements, ear notching qualifies as official identification if the ear notching has been recorded in the book of record of a purebred registry association. This means you cannot simply notch a pig and call it registered — the notch number must be submitted to the appropriate breed association, and the registration certificate must be issued and kept on file.
When you move a registered pig within Colorado or import one from another state, the registration certificate must accompany the animal. A Certificate of Veterinary Inspection (CVI) is an official document issued by an accredited veterinarian at the point of origin of a shipment of livestock. It must include the date, the premises of origin, name and address of the consignor, the premises of destination, the name and address of the consignee, the age, sex, number, and breed of the livestock, and sufficient identifying marks, tags, or other identification as may be approved by the state veterinarian to positively identify livestock.
For 4-H and FFA exhibitors in Colorado, county fairs, the Colorado State Fair, and other exhibitions — both in-state and out-of-state — require premises registration as part of the enrollment process. If your exhibition pig is a registered purebred with a notch on file with a breed association, that notch serves as its individual identification. If your pig is a commercial or crossbred animal, you will need an alternative form of official ID such as an 840 RFID tag.
| Pig Type | Ear Notch Counts as Official ID? | Additional Requirement |
|---|---|---|
| Registered purebred (Duroc, Hampshire, etc.) | Yes | Notch recorded with breed registry; registration certificate travels with animal |
| Commercial/crossbred feeder pig | No | Requires 840 RFID tag, silver brite tag, or premises tattoo |
| 4-H/FFA exhibition pig (purebred) | Yes, if registered | Registration papers required at fair enrollment |
| 4-H/FFA exhibition pig (commercial) | No | Official eartag or other approved ID required |
| Breeding stock moving interstate | Yes, if registered | CVI + registration certificate required |
Ear Notching vs. Ear Tags, Tattoos, and RFID in Colorado
Colorado accepts several forms of official swine identification, and each has practical trade-offs depending on your operation’s size, purpose, and movement needs. Understanding how ear notching compares to the alternatives helps you choose the right method — or combination of methods — for your herd.
840 RFID Tags are the most broadly accepted form of official swine ID in Colorado and nationally. AIN tags begin with the official country code “840” for the U.S., followed by 12 digits, and are available with radio frequency identification technology that allows them to be readable both visually and electronically. These tags work for all swine categories — breeding, feeding, and exhibition — and do not require breed registry paperwork. The downside is that tags can be lost or torn out, especially in group housing.
Ear Notching is permanent and costs almost nothing beyond the notching tool, but its official ID status is limited to registered purebreds. Ear notches can be used for breeding, feeding, and exhibition swine — but only when backed by registry records. For commercial operations or mixed-breed pigs, notching remains a useful herd management tool without carrying official ID weight.
Tattoos offer a middle ground. Tattoos on the ear or inner flank of any swine qualify as official identification if the tattoos have been recorded in the book of record of a swine registry association. For slaughter swine and feeder swine, an eartag or tattoo bearing the Premises Identification Number assigned by the State Animal Health Official to the premises on which the swine originated also qualifies. Tattoos are permanent like notches but require more equipment and skill to apply legibly.
USDA Backtags are a slaughter-channel-only option. USDA backtags are approved only when used on swine moving in slaughter channels. They are not suitable for breeding stock, exhibition animals, or any pig that will remain in production.
- 840 RFID tag: Broadest acceptance; works for all swine types; risk of tag loss
- Registered ear notch: Permanent and free after initial tool cost; restricted to registered purebreds
- Breed registry tattoo: Permanent; requires registry paperwork; useful when notching is impractical
- Premises tattoo (PIN): Accepted for slaughter and feeder swine; ties pig to originating farm
- Microchip: Accepted by Colorado for swine import; requires scanner; growing in use for pet pigs
- USDA backtag: Slaughter channel only; not valid for breeding or exhibition
Important Note: Colorado accepts microchips as official swine identification for import purposes. If you keep a pet pig or miniature pig and plan to travel with it, a microchip may be a more practical choice than an ear notch or eartag. Confirm chip compatibility with your veterinarian before travel.
For more on how Colorado’s broader livestock identification rules apply to animals moving across state lines, see this overview of transporting livestock laws in Colorado.
State-Specific Swine Identification Rules That Affect Ear Notching in Colorado
Colorado’s swine identification framework sits at the intersection of state agricultural rules and federal USDA APHIS requirements. Knowing which layer of regulation applies to your situation keeps you from being caught off guard at a livestock market, state fair, or border crossing.
Certificate of Veterinary Inspection (CVI) Requirements
Any swine imported into Colorado must be accompanied by a valid CVI issued by an accredited veterinarian at the point of origin. A CVI is void thirty days after the date of its issuance. One copy of such certificate shall accompany the animals. If your registered pig’s ear notch serves as its official ID, the registration certificate must accompany the CVI — the notch number alone on the CVI is not sufficient without the paperwork linking it to the breed registry record.
Animals Entering Without Documentation
Animals entering the state without a valid health certificate or permit number, or both if required, may be held in quarantine at the risk and expense of the owner until released by an authorized representative of the State Veterinarian. This applies to swine regardless of identification method. A notched pig without its registration certificate is in the same position as an untagged commercial pig — it cannot enter Colorado legally without proper paperwork.
Swine Production Health Plan Exemption
Large commercial operations moving swine into Colorado have a pathway that bypasses the standard CVI and official ID requirements. Commercial swine moved into Colorado under a current Swine Production Health Plan may be exempt from CVI and Official Identification requirements. This plan is negotiated between the operation and the Colorado State Veterinarian and is not available to small farms or individual producers moving a handful of animals.
Garbage Feeding Rules
Colorado also regulates what you feed your pigs, which intersects with identification in disease-control contexts. No person may feed garbage to swine without approval from the State Veterinarian. Operations that feed garbage must maintain registration with the state, and their animals are subject to additional oversight — making reliable individual identification, whether by notch or tag, especially important for traceability.
Premises Registration
Beyond premises registration, individual animal identification is required for movement and import purposes. Health certificates must show the date of shipment, the names and addresses of the consignor and consignee, species of livestock, number, sex, breed, and age, and sufficient identifying brands, marks, tags, and other identification to positively identify the livestock. Before your ear notch can do any official work for you, your farm must be registered as a premises with the Colorado Department of Agriculture. County fairs, the Colorado State Fair, and other exhibitions — both in-state and out-of-state — require premises registration as part of the enrollment process.
Colorado’s Department of Agriculture livestock FAQ page confirms that swine are among the species subject to dealer licensing and brand inspection requirements when ownership changes hands. Brand inspection is mandatory with any change of ownership of livestock, and swine are included in that definition. If you sell a registered pig whose identification is its ear notch, a brand inspection may still be required at the point of sale.
If you raise other livestock alongside your pigs, Colorado’s animal law framework covers those species too. See related guides on goat ownership laws in Colorado and backyard chicken laws in Colorado for how identification and movement rules differ across species. For a broader look at how Colorado regulates animal ownership and movement, the guides on pet import laws in Colorado and animal cruelty laws in Colorado provide useful context.
The bottom line for Colorado swine producers: ear notching remains a legally recognized and practical identification method, but only when it is backed by breed registry records and accompanied by the right paperwork. A notch without a registry record is a farm management tool, not official ID. Get your premises registered, work with an accredited veterinarian on your CVIs, and keep registration certificates with every animal that moves off your property — and you will have no trouble meeting Colorado’s requirements.