Livestock Ear Tag Requirements in Colorado: What Every Producer Must Know

If you raise cattle, sheep, goats, or other livestock in Colorado, official ear tag identification is not optional — it is a legal requirement tied to federal disease traceability programs and Colorado Department of Agriculture (CDA) rules. Getting it wrong can mean animals turned away at state lines, fines, or forced tagging at your expense.

The rules changed significantly on November 5, 2024, when a new federal mandate took effect requiring electronic identification (EID) ear tags for certain classes of cattle and bison. Whether you run a commercial cow-calf operation on the Eastern Plains, a small sheep flock in the San Luis Valley, or a hobby farm along the Front Range, this guide walks you through exactly what Colorado requires — species by species — and what you need to do to stay compliant.

Which Animals Require Official Ear Tags in Colorado

Not every animal on your Colorado farm or ranch needs an official government-issued ear tag, but the list is broader than many producers expect. Under Colorado law, “livestock” includes cattle, horses, mules, burros, sheep, poultry, swine, llama, cervids, bison, and goats, regardless of use. Official ear tag requirements apply across several of these species when animals change ownership, move interstate, enter shows or exhibitions, or participate in federal disease control programs.

At the federal level, the animals most directly affected by official ID requirements are cattle and bison moving across state lines. The rule covers all sexually intact cattle and bison 18 months of age or older, all dairy cattle of any age (including dairy-beef cross calves), cattle and bison of any age used for rodeo or recreational events, and cattle and bison of any age used for shows or exhibitions. Sheep and goats face separate scrapie-program identification rules, while swine have their own premises-based tagging system.

Pro Tip: Even if your animals never leave Colorado, official ID may still be required for disease program participation, tuberculosis testing, or exhibition at the Colorado State Fair. Register your premises with the CDA before you need tags — it is a prerequisite for ordering them.

Colorado exhibition rules reinforce federal requirements. All exhibition cattle, regardless of age or sex, are required to have an official USDA-approved unique identification ear tag placed in the ear; breed tattoos and brands are not considered official for Certificates of Veterinary Inspection (CVIs) in Colorado. If you plan to show animals at the National Western Stock Show or the Colorado State Fair, this rule applies to you.

Federal RFID Ear Tag Rule: What Changed in November 2024

The most significant shift in livestock identification in a generation took effect on November 5, 2024. USDA APHIS amended the animal disease traceability regulations to require that ear tags applied on or after that date be both visually and electronically readable in order to be recognized as official ear tags for interstate movement of covered cattle and bison. The rule was published in the Federal Register on May 9, 2024, giving producers roughly six months to prepare.

Before this change, a silver metal National Uniform Eartagging System (NUES) tag — the familiar “brite” tag — was acceptable as official ID for cattle. On November 5, 2024, new federal rules took effect requiring electronic identification (EID) ear tags for certain cattle and bison moving across state lines, replacing the old system of visual-only metal tags with radio frequency identification (RFID) tags that can be read electronically.

The good news for producers who already had animals tagged before the deadline: cattle tagged with visual-only official tags prior to November 5, 2024, do not need to be retagged unless they lose their ID. That grandfathering provision applies for the life of the animal. Animals that have previous official ID tags in place with the USDA shield present do not have to replace those tags, as they are good for the life of the animal.

The rationale behind the rule is rapid disease response. Electronic identification tags and systems provide many advantages over traditional metal tags, including faster information sharing, more accurate and precise identification of animals, and significantly faster record searches during disease outbreaks. The H5N1 outbreak in dairy cattle highlighted exactly why faster traceability matters for Colorado producers and the broader livestock industry.

Important Note: The November 2024 rule did not add new categories of livestock to the official ID requirement. It only changed the type of tag required for animals already covered. Beef feeder cattle under 18 months moving intrastate are still generally exempt, though destination-state rules may vary.

Official 840 RFID Ear Tag Requirements in Colorado

When you need an official ear tag for cattle or bison in Colorado today, that tag must be an 840 RFID tag. The only official tags that meet current requirements are 840 RFID tags, and this requirement applies to official identification placed for any reason, including interstate movement, brucellosis vaccination, and tuberculosis testing.

The “840” designation refers to the United States’ ISO country code. USDA tags have a unique 15-digit number starting with “840,” display the USDA shield emblem, and include an “Unlawful to Remove” print. Approved tags must be tamper-resistant, have a high retention rate of at least 99%, and start with the three numbers 840. Tags in the 900 series are not accepted as official identification, even if they are electronically readable.

Two EID technologies are approved under U.S. standards: both HDX (half-duplex) and FDX (full-duplex) low-frequency ear tags meet U.S. standards for official EID, and either is acceptable for official purposes — choose based on your reader equipment and management software. HDX tags can be read from a greater distance and work well in automated systems, while FDX tags are generally a more cost-effective option for smaller operations.

Before you can order 840 RFID tags, you need a Premises Identification Number (PIN). A Premises ID is required to purchase USDA tags, which have a unique 15-digit number starting with “840,” display the USDA shield emblem, and include an “Unlawful to Remove” print. You can register your premises by contacting the Colorado Department of Agriculture Animal Health Division at 303-869-9130 or animalhealth@state.co.us.

Species-Specific Ear Tag Rules in Colorado

Each livestock species in Colorado operates under a distinct identification framework. Understanding the rules for your specific animals prevents compliance gaps and keeps your operation running smoothly.

Cattle and Bison

Cattle and bison face the strictest and most recently updated requirements. As described above, any official ID applied after November 5, 2024, must be an 840 RFID tag. This covers dairy cattle of all ages, sexually intact beef cattle and bison 18 months or older, and any cattle or bison used for rodeo, recreation, shows, or exhibitions. The definition of dairy cattle now includes any crosses of Ayrshire, Brown Swiss, Holstein, Jersey, Guernsey, Milking Shorthorn, Red and White, and their offspring — a clarification that matters for Colorado’s dairy operations along the Front Range and in Weld County.

For brucellosis vaccination, the new official brucellosis identification is an orange RFID button, placed in the right ear by the herd veterinarian at the time of vaccination. USDA recommends reserving the right ear for official use and placing producer-applied tags in the left ear.

Sheep

Sheep identification in Colorado is governed by the federal National Scrapie Eradication Program, not the November 2024 RFID cattle rule. The mandatory USDA identification program for sheep covers all sheep over 18 months of age; sexually intact sheep under 18 months of age that are sold for breeding or exhibition; sheep sold unrestricted; sheep not in slaughter channels; and sheep that have lambed or are pregnant.

For sheep and goats, USDA-approved scrapie identification ear tags listing the flock of origin and individual number are required. At Colorado livestock auctions, all sexually intact sheep regardless of age and wethers 18 months of age and older are required to have tags upon change of ownership or when sold as cull animals, and all sexually intact sheep regardless of age and wethers 18 months of age and older are required for show or exhibition.

Goats

Goats follow scrapie program rules similar to sheep, with some additional nuances. Sexually intact goats not in slaughter channels of any age that do not meet the requirements to be considered low-risk commercial goats — such as those that are registered or sold for commercial milk production — require official identification. Colorado has had documented scrapie cases in goats, which means state officials apply these rules carefully.

Goats with a legible tattoo may use that tattoo in place of a scrapie ear tag, but only when accompanied by a breed registration certificate from the respective goat breed association. All sexually intact goats including market goats must have a Scrapie Premises ID ear tag for Colorado State Fair exhibition.

Swine

Swine identification in Colorado centers on premises-level identification rather than individual animal ear tags in most situations. Premises Identification Number (PIN) tags for slaughter swine are available directly from authorized manufacturers. For exhibition swine, ear notching is a common identification method used at Colorado county fairs alongside premises ID tags.

USDA APHIS has also launched a no-cost EID tag program for swine. USDA APHIS announced an initiative to provide no-cost EID tags for swine beginning fall 2025, available for sow and exhibition swine producers, who can order tags through the Merck Animal Health website at www.840swinetags.com.

Equine, Camelids, and Cervids

Horses and other equine in Colorado do not require official ear tags for most routine movement, but they do need a CVI for interstate travel and may require a negative Coggins test. 840 AINs are available in microchip implants for equine and other species for producers who want to participate in traceability programs voluntarily. Camelids (llamas and alpacas) and cervids (deer and elk) kept in captivity may require identification for exhibition and interstate movement — contact the CDA Animal Health Division for current requirements specific to those species.

Where to Get Official Ear Tags in Colorado

You have several options for sourcing official 840 RFID ear tags in Colorado, and your PIN must be in hand before you order from any of them.

• Colorado Department of Agriculture Animal Health Division — Contact the CDA at 303-869-9130 or animalhealth@state.co.us. The state office distributes tags and can confirm current stock availability. Many state veterinarian offices distribute free 840 RFID tags to producers, but supply has been uneven.
• USDA APHIS Veterinary Services — For scrapie tags for sheep and goats, call 1-866-USDA-Tag (866-873-2824). The National Scrapie Eradication Program provides up to 100 plastic flock ID tags free of charge to first-time participants until available funds are expended.
• Approved tag manufacturers — Three major manufacturers produce approved 840 tags: Allflex (Dallas, TX), Datamars (Temple, TX), and Y-Tex (Cody, WY). Y-Tex is particularly convenient for Colorado producers given its proximity in Cody, Wyoming. RFID 840 tags cost between $2 and $5 per tag, depending on the manufacturer, tag style, and order quantity.
• Veterinary supply distributors and farm supply stores — Tags are available through veterinary supply distributors, farm supply stores, and directly from manufacturers. Your accredited veterinarian may also keep a supply on hand.
• Your accredited veterinarian — Vets who perform official health certifications often stock 840 RFID tags and can apply them at the time of a CVI examination.

Pro Tip: Colorado producers can also become AIN Device Managers, which allows them to redistribute official 840 EID tags to other producers. Visit aphis.usda.gov/livestock-poultry-disease/traceability and refer to the “How to Become an AIN Device Manager” section for details.

How and When to Apply Ear Tags in Colorado

Proper tag placement protects tag retention and ensures the number remains readable — both visually and electronically. All ear tags should be placed two-thirds of the way from the outside edge of the ear, and one-third of the way from the head between the middle two cartilage ribs. Placing tags too close to the edge of the ear increases the risk of tearing, while tags placed too close to the head can be harder to read.

RFID tags are recommended to be placed in the left ear, leaving the right ear available for official brucellosis vaccination tags and tattoos applied by your herd veterinarian. If a visual tag and an EID button are placed in the same ear, the EID button should go in the standard location with the visual tag a little closer to the outside of the ear. The female (thicker) portion of the tag should always face the inside of the ear.

For sheep and goats, scrapie tags should be placed between the main two ribs on the inner third of the left ear. Use the correct applicator — each tag manufacturer specifies a compatible applicator, and using the wrong tool can damage the tag’s electronic component or reduce retention.

Timing matters as well. Tag cattle and bison before they leave your premises for any covered movement. Animals required to have an EID tag and leaving a premises for interstate movement should have one in place when leaving the premises. Do not wait until you arrive at a livestock market or sale barn — some markets will apply tags at the owner’s expense if animals arrive untagged, and that cost adds up quickly.

Species	Tag Type Required	When Required	Recommended Ear
Cattle / Bison (covered classes)	840 RFID EID tag (if tagged after Nov. 5, 2024)	Before interstate movement, exhibition, brucellosis vaccination, TB testing	Left ear
Sheep	USDA-approved scrapie flock ID tag	Change of ownership, interstate movement, exhibition	Left ear
Goats	USDA-approved scrapie flock ID tag (or registry tattoo with papers)	Change of ownership, interstate movement, exhibition	Left ear
Swine (slaughter / exhibition)	Premises ID tag or ear notch	Exhibition; interstate movement per destination state rules	Either ear

Ear Tag Requirements for Interstate Movement in Colorado

Moving livestock out of Colorado — or receiving animals from another state — triggers a specific set of federal and state requirements that go beyond simply having a tag in the ear. For a full picture of what Colorado requires when hauling animals across state lines, see this overview of transporting livestock laws in Colorado and the related livestock trailer requirements in Colorado.

Every covered animal moving interstate must have its official ID number recorded on a Certificate of Veterinary Inspection (CVI) issued by an accredited veterinarian. The types of cattle that must be identified when moving interstate have not changed under the November 2024 rule — all dairy females and males born after March 11, 2013, exhibition and rodeo cattle, and sexually intact beef cattle 18 months of age and older must be officially identified before moving interstate.

Destination-state rules add another layer. If animals are crossing state lines and an official ID is required, all parties involved are responsible for knowing the requirements of the state of destination — including the breeder, livestock market, shipper, hauler, broker, veterinarian, and buyer. Before moving cattle from Colorado into neighboring states like Wyoming, Kansas, or Nebraska, confirm that destination state’s import requirements. Producers moving into Wyoming should also review livestock trailer requirements in Wyoming, and those heading to Kansas can check livestock trailer requirements in Kansas.

There is one notable exemption: commuter herds operating with a commuter herd agreement between states or tribes are exempt from the standard interstate ID requirement. Colorado producers who regularly move cattle across a state line as part of grazing operations should contact the CDA and their destination state’s animal health office to establish a formal commuter herd agreement.

For sheep and goats moving interstate, the CVI must include each animal’s official scrapie tag number or registry tattoo information. Individual animal identification numbers — including official ear tag numbers, breed association registration tattoo or brand numbers, and any other official individual identification — must be recorded on each animal to be moved. Colorado also requires a brand inspection for cattle and horses leaving the state, which is a separate but parallel requirement to official ear tagging.

Recordkeeping Requirements for Ear-Tagged Animals in Colorado

Owning official ear tags and applying them correctly is only part of your compliance obligation. You also need to maintain records that link each tag number to a specific animal and document every movement, replacement, or change in identification.

At the federal level, tag distribution records are foundational to the traceability system. Official ear tags provide animal health officials with a specific starting point from which to trace diseased or potentially diseased animals, and the required tag distribution records associate the official identification number with the person that received the device. This means the records start before the tag even goes in the animal’s ear — when you receive tags from a distributor or the state office, that transaction is logged.

For your own operation, keep the following records for each tagged animal:

• The 15-digit AIN from the 840 RFID tag
• The date the tag was applied
• The animal’s species, breed, sex, and approximate age or date of birth
• Your Premises Identification Number (PIN)
• The location where the tag was applied

If a tag is lost or damaged, replacement is allowed but must be documented. If a tag is lost, it can be replaced with permission using a new EID tag. The new tag number should be recorded along with the date and location of the replacement. If the old number is known, that should be noted as well. When you apply a replacement EID tag to an animal that already had official ID, record both the old and new tag numbers and the date of the replacement.

Colorado’s tuberculosis testing rules reinforce these recordkeeping obligations. The official USDA test form for all tuberculin tests must include individual identification of each animal by official ear tag number, official animal identification number, individual permanent numerical brand, or registration tattoo, along with age, sex, and breed. All premises where testing for tuberculosis occurs must have a PIN.

Pro Tip: An EID reader is not legally required to manage your herd’s records, but it makes the process significantly faster and reduces transcription errors. It is not necessary to use an EID reader, but scanning tags can make it quicker and easier to accurately record the tag number. Many Colorado producers find that a basic wand reader pays for itself quickly when managing large herds through a working chute.

Keep all tag records, CVIs, and movement documents for a minimum of five years — the standard recommended by USDA APHIS for traceability purposes. Store them in a format you can produce quickly if a disease investigation requires it. Digital records backed up to a cloud service are a practical option for busy Colorado operations.

For questions about Colorado-specific recordkeeping rules, contact the CDA Animal Health Division at 303-869-9130 or animalhealth@state.co.us, Monday through Friday, 8 a.m. to 5 p.m. You can also review the USDA APHIS Animal Disease Traceability page for national standards. Producers with questions about how ear tag compliance intersects with other Colorado livestock rules — including rabies vaccine requirements or brand inspection requirements — will find that most of these programs share the same PIN-based foundation, so getting your premises registered once puts you in good standing across the board.