Swine Ear Notching Laws in Oklahoma: What Every Producer Needs to Know

If you raise pigs in Oklahoma — whether for show, breeding, or commercial production — understanding swine ear notching rules can save you from compliance headaches and registration rejections. Ear notching has been a staple of swine identification for decades, but its legal standing, practical requirements, and relationship to newer technologies like RFID tags are often misunderstood.

Oklahoma producers operate under a layered system of state and federal rules. The Oklahoma Department of Agriculture, Food, and Forestry (ODAFF) sets state-level requirements, while USDA’s Animal and Plant Health Inspection Service (APHIS) governs interstate movement. Knowing which rules apply to your specific operation — and when ear notching counts as official ID — is the foundation of legal compliance.

This guide walks you through everything you need to know about swine ear notching in Oklahoma: when it qualifies as official identification, how the 1-3-9 system works, registry requirements, and how ear notching stacks up against ear tags, tattoos, and RFID.

What Is Swine Ear Notching and When It Is Used in Oklahoma

Ear notching is a permanent form of swine identification that involves removing small V-shaped pieces of tissue from specific positions along a pig’s ear. It is widely used in the swine industry as a system of animal identification, with variations in systems that all identify a pig by litter number and individual pig number. Because the notches are cut into the ear cartilage at birth, the identification is truly permanent and cannot be lost or removed like an ear tag.

In Oklahoma, ear notching is most commonly applied in three contexts: purebred herd management, 4-H and FFA show pig programs, and small-scale farrow-to-finish operations where producers want a low-cost, permanent on-farm ID system. An accurate set of records on swine performance is one of the best management tools a producer can have, and in order to keep such records, producers must be able to identify pigs from birth.

The procedure is typically performed within the first few days of life. The successful manager clips the needle teeth and navel cords as soon after birth as possible, which also offers an opportune time for identification, and the simplest method recommended by most breed associations is ear notching. A small V-notcher tool is used to make clean cuts at designated positions on each ear.

Pro Tip: Perform ear notching within the first 24 to 48 hours after birth. At this age, piglets are easier to handle, tissue heals quickly, and the notch positions are easier to read accurately as the ear grows.

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 Oklahoma swine producers, the method remains practical and cost-effective — especially for small to mid-sized operations that do not require the electronic data integration offered by RFID systems.

When Ear Notching Qualifies as Official Identification in Oklahoma

Not every ear notch automatically qualifies as official identification under Oklahoma or federal law. The legal standing of ear notching as official ID depends entirely on whether the notching has been recorded with a recognized purebred registry association. This is a critical distinction that affects how you can legally move, sell, or show your animals.

Under federal regulations governing interstate swine movement, ear notching qualifies as official identification when used on any swine if the ear notching has been recorded in the book of record of a purebred registry association. The same rule is codified in the Code of Federal Regulations at 9 CFR § 71.19, which governs the identification of swine in interstate commerce.

This means that if you are raising commercial market hogs or crossbred pigs with no registry affiliation, an ear notch alone does not satisfy official ID requirements. 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 is required. Oklahoma producers moving feeder or slaughter pigs across state lines must use a Premises Identification Number (PIN) tag or tattoo — not just an ear notch.

For swine imported into Oklahoma, the state’s requirements are even more specific. Sale, show, and pet swine entering Oklahoma require a permit, a Certificate of Veterinary Inspection issued within 30 days of entry, individual ID by official USDA ear tag, and a negative Brucellosis and Pseudorabies test within 30 days prior to entry, or origination from a Validated/Qualified Herd. You can review the full import requirements on the Oklahoma Department of Agriculture’s animal import requirements page.

Important Note: An ear notch only counts as official ID when it is backed by a registry record. If you plan to show or sell registered purebred pigs in Oklahoma, make sure the notch is recorded with the appropriate breed association before the animal leaves your premises.

How the 1-3-9 Ear Notching System Works

The most widely used ear notching method in the United States — and the one recognized by purebred swine associations — is the 1-3-9 system. The most common notching system is the 1-3-9 system. Understanding this system is essential for any Oklahoma producer who wants their ear notching to be readable by buyers, show judges, and registry officials.

The system works by assigning numerical values to specific positions on each ear. The litter number is notched in the pig’s right ear, and the individual pig number is notched in the pig’s left ear, and the notches from the right and left ear should combine to give each pig a unique identification number. Every pig in the same litter shares the same right-ear notch pattern, while the left ear distinguishes individual animals within that litter.

The numerical values assigned to ear positions follow a consistent pattern. Working from the bottom of the right ear upward, the positions represent values of 1, 3, and 9. The top notch (ear tip) carries a value of 27. On the left ear, the same positional values apply for individual pig numbering. 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, and 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.

Ear Position	Right Ear Value (Litter)	Left Ear Value (Individual Pig)
Bottom of ear	1	1
Middle of ear	3	3
Upper portion	9	9
Ear tip (top)	27	27

For example, a pig from litter number 4 would have notches at the 1 and 3 positions on the right ear (1 + 3 = 4). If it is the 5th pig in that litter, the left ear would carry notches at the 1 and 4… at the 1 and the 3 positions as well (1 + 3 = 4 would be a different pig; for pig 5, you use the 1 and the 3+1 combination). The system allows for litter numbers up to 40 using standard positions, and the capacity can be extended. No more than two notches may be made at any position, and when these positions are filled in the right ear, an 81 notch placed in the tip doubles the system.

For piglets of this size, a small 3/16- to 1/4-inch-deep V-notcher is recommended. Clean, sharp cuts placed precisely in the correct zone are what make the system readable for years to come. Sloppy or misplaced notches can create confusion at weigh-ins, sale barns, and breed registry offices.

Pro Tip: Keep a written litter log alongside your ear notching records. Write down the right-ear notch value (litter number), the date of birth, dam ID, and sire ID for every litter. This documentation is what registry associations and ODAFF officials will ask to see.

Ear Notching for Purebred Registry Compliance in Oklahoma

If you raise registered purebred swine in Oklahoma — including breeds like Duroc, Hampshire, Yorkshire, Berkshire, or Chester White — ear notching is closely tied to your breed association’s registration requirements. The notch is not just a farm management tool; it becomes part of the official record that travels with the animal throughout its life.

When using the system of ear notching required by the purebred swine associations of the United States, the litter number is notched in the pig’s right ear, and the individual pig number is notched in the pig’s left ear. This standardized approach ensures that any accredited buyer, show official, or veterinarian can read and verify the ID without needing farm-specific codebooks.

The National Swine Registry (NSR) — which covers Duroc, Hampshire, Yorkshire, and Landrace — requires that ear notch data be recorded on litter registration applications. Notches in the left ear identify individual pigs in the same litter, and all littermates will have different notches in the left ear. You submit this information when registering a litter, and the registry assigns permanent pedigree records tied to those notch values.

For Oklahoma 4-H and FFA exhibitors, ear notching is particularly important. Show pigs entered in county fairs, the Oklahoma Youth Expo, or state-level competitions typically must be individually identified, and a registry-backed ear notch satisfies that requirement for purebred classes. Commercial show pig divisions may require an official ear tag instead — always verify the specific show’s rulebook before entry day.

According to USDA APHIS, 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 the paperwork must be completed and on file before the animal moves — not after the fact.

Ear Notching vs. Ear Tags, Tattoos, and RFID in Oklahoma

Oklahoma swine producers have several identification options available, and choosing the right method — or the right combination — depends on your operation type, whether you move animals across state lines, and whether you participate in shows or commercial slaughter channels. Each method has distinct legal standing, practical strengths, and limitations.

ID Method	Permanent?	Official ID for Interstate Movement?	Best Use Case
Ear Notching	Yes	Only if registry-recorded	Purebred/show pigs, on-farm ID
Official Ear Tag (PIN)	No (can be lost)	Yes (feeder/slaughter swine)	Commercial, feeder, and slaughter pigs
Tattoo	Yes	Yes (if registry-recorded or PIN)	Registered breeding stock, slaughter ID
RFID Tag (840)	No (can be lost)	Yes	Sows, exhibition swine, traceability programs

There are two types of identification: permanent and nonpermanent. Permanent IDs stick with an animal through its entire life and include tattooing and ear notching. Non-permanent IDs can be lost or removed from the animal and include things like ear tags. This distinction matters in Oklahoma because if a commercial ear tag falls out during transport, the animal may arrive at a sale barn or slaughter facility without traceable ID.

Tattoos offer a strong middle ground. Tattoos win on permanence — ink placed inside the ear lasts the life of the animal and cannot be lost or altered easily, which is why breed registries often require them. The limitation is readability: you need to restrain the animal and flip the ear to read a tattoo, making it impractical for quick sorting at a distance.

RFID technology is rapidly becoming the standard for swine traceability at the federal level. APHIS is offering no-cost radio frequency identification (RFID) eartags to eligible swine producers, and this program will enhance the speed and accuracy of disease response efforts across the swine industry. In July 2025, APHIS awarded a contract to Merck Animal Health to supply up to $20 million in tags to sow and exhibition swine industry segments over the next five years. Oklahoma producers with valid Premises Identification Numbers can access this program through USDA APHIS’s swine identification page.

For most small Oklahoma operations raising registered purebreds, ear notching combined with a tattoo provides the most complete permanent ID package. For commercial hog operations moving feeder pigs or slaughter hogs, a PIN ear tag or PIN tattoo is the practical choice. If you raise sows or show pigs and want to participate in federal disease traceability programs, RFID is worth adding to your system. You can learn more about how Oklahoma regulates the transportation of livestock — including swine — in our guide to transporting livestock laws in Oklahoma.

State-Specific Swine Identification Rules That Affect Ear Notching in Oklahoma

Oklahoma’s swine identification framework is administered by the Oklahoma Department of Agriculture, Food, and Forestry (ODAFF), and it interacts with federal APHIS rules at several key points. Understanding where state law adds requirements — beyond the federal baseline — is essential for full compliance.

Oklahoma requires a Premises Identification Number (PIN) for any swine operation that moves animals commercially or participates in regulated health programs. This PIN is assigned by ODAFF’s state animal health official and becomes the foundation for all official ID methods, including PIN ear tags and PIN tattoos used on feeder and slaughter pigs. Serial numbers of official eartags will be assigned to each accredited veterinarian or State or Federal representative who requests official eartags from the State animal health official or the area veterinarian in charge, whoever is responsible for issuing official eartags in that State.

For swine moving into Oklahoma from other states, ODAFF enforces strict import health requirements. A permit, CVI within 30 days of entry, individual ID, and a negative Brucellosis and Pseudorabies test within 30 days prior to entry are required. An ear notch alone will not satisfy the individual ID requirement for imported swine — you will need an official USDA ear tag unless the animal is a registered purebred accompanied by valid registry documentation that includes the notch record.

Oklahoma also has separate and significant rules governing feral swine, which are treated as a distinct legal category from domestic hogs. Feral swine are a nonnative invasive species in Oklahoma that are detrimental to the natural resources of Oklahoma and agriculture production and a disease risk, and as the feral swine population increases, citizens continue to see increased damage to crops, livestock, and wildlife habitat. Ear notching does not apply to feral swine management — those animals fall under the Oklahoma Feral Swine Control Act, not agricultural identification rules.

All persons that transport live feral swine in Oklahoma are required to obtain a transporter license from the Oklahoma Department of Agriculture, Food, and Forestry. This is a completely separate requirement from the domestic swine identification rules that govern ear notching and registry compliance. If you are dealing with feral hogs on your property, refer to the Oklahoma Feral Swine Control Act regulations rather than standard livestock ID rules.

For producers whose operations involve multiple animal species or broader agricultural compliance questions, it helps to understand Oklahoma’s wider regulatory environment. Our guides on goat ownership laws in Oklahoma and backyard chicken laws in Oklahoma cover identification and ownership rules for other common livestock species. If you import any animals into the state, the pet import laws in Oklahoma guide provides additional context on health certificate and permit requirements.

Important Note: Oklahoma’s swine identification rules are subject to change through ODAFF rulemaking and federal APHIS guidance. Always verify current requirements directly with the Oklahoma Department of Agriculture, Food, and Forestry before moving swine across state lines or entering animals in regulated shows.

Staying compliant with swine ear notching rules in Oklahoma comes down to three practical habits: notch accurately using the 1-3-9 system, record every notch with the appropriate breed registry if you want official ID status, and layer your identification methods based on how and where your animals will move. Whether you are managing a purebred Duroc herd, prepping show pigs for the Oklahoma Youth Expo, or running a commercial farrow-to-finish operation, the right ID system protects your animals, your records, and your ability to do business across state and county lines.

For questions specific to your operation, contact the ODAFF Animal Industry Division directly or consult an accredited veterinarian familiar with Oklahoma swine health regulations. You can also explore related Oklahoma animal law topics — including pet vaccination laws in Oklahoma and kennel zoning laws in Oklahoma — for a fuller picture of how the state regulates animal ownership and management.