Dr. Michelle Arnold, Ruminant Extension Veterinarian, University of Kentucky

The new Animal Disease Traceability (ADT) rule, entitled “Use of Electronic Identification (EID) Eartags as Official Identification in Cattle and Bison”, was published in the Federal Register on 5/9/2024 and will be effective on 11/5/2024. This final rule, available at https://www.regulations.gov/document/APHIS-2021-0020-2011 is an amendment to the animal disease traceability regulations already in place as of January 2013. One stipulation in the new rule requires eartags to be both visually and electronically readable to be recognized as official eartags for interstate travel for cattle and bison covered under the regulations. This final rule does not require exclusive use of eartags; the regulations continue to list eartags as one of several forms of authorized official identification, which also include tattoos and brands when accepted by State officials in the sending and receiving States. This article will address questions about eartag differences with regards to the new rule. For more in-depth information, there is a new guidance document entitled “OFFICIAL ANIMAL IDENTIFICATION NUMBER (AIN) DEVICES WITH THE “840” PREFIX”, published 5/14/2024, available at https://www.aphis.usda.gov/media/document/64512/file .

What does it mean that an official tag must be “visually and electronically readable” for interstate travel? Are the RFID “button tags” considered visually readable or will flop tags/panel tags be required?

All tags must be readable in cattle, but USDA now has device readability standards, both electronic and visual standards, that must be met by tag manufacturers to obtain approval for official identification purposes that meet interstate travel requirements. In Version 3.0 of the ADT Device Standards, released 9/21/2023, the specifications are described in detail regarding readability:

• Electronic ID eartags are required to be visually readable for a person with 20/20 vision (arm’s length) viewing from two-and-a-half feet (30 inches). RFID button tags meet this standard, so a panel tag is not required in order to be “visual”.
• All official identification numbers must be imprinted at a minimum height of 5 mm (0.2 inches) on a bright, contrasting background. An exception may be made for small EID ear tags that do not allow the imprinting of the official identification number at 5 mm but are clearly read at the required distance.
• For 840 tags, a space must be inserted after each third digit of the animal identification number (AIN) imprinted on the tag (for example, 840 003 123 456 789).
• The font for all characters for required information imprinted on the tag must be Arial. APHIS must approve any different font.

Electronic ID eartags can also be read using an RFID reader. This reader sends a radio signal of a specific frequency to the eartag and records the number that comes back from the eartag. Once a signal is received from the reader, the eartag transmits the identity of an animal in the form of a unique 15-digit sequence of numbers. The 15-digit sequence begins with the country code (e.g., 840 for US born animals), followed by 003, then 9 unique digits. Official USDA-APHIS electronic eartags have no batteries or active transmission of information but are often categorized by the radio frequency range they use to communicate, either low (LF) or ultrahigh frequency (UHF). Low frequency tags have a shorter read range and only one tag can be read at a time. The transponders must be reliably machine read at a rate of 95 percent as cattle move by in a single file passage at 4 mph. UHF has an extended read range of up to 30 feet, faster data transfer, and is better suited to capturing load lots of cattle. UHF transponders must be reliably machine read at a rate of 95 percent at the read distance designated by the device manufacturer.

Why the push for both visually and electronically readable official tags?
Reading eartags electronically does not require restraint of animals because animal identification information is captured almost instantaneously by scanning the eartag with a reader. Once the tag is scanned, the tag number may be rapidly and accurately transmitted to a connected database. Electronic databases store only data associated with an eartag number that is necessary to perform traceability of animals; no business practices or other financial or competitive information is obtained or stored. Electronic eartags help animal health officials more quickly locate the records associated with an animal during a disease trace to identify the origin of the animal. If the animal was tagged with an electronic eartag, the tag distribution records are stored in APHIS’ Animal Identification Number Management System database (AIMS), which is easily accessible to animal health officials and provides the starting point for the trace. However, if visual only tags have been used, the animal usually must be restrained to allow the eartag number to be read and recorded. Often, the eartag must be cleaned before the number can be read. The eartag number is then recorded on paper or manually entered in a database and errors can occur while reading, transcribing, or entering the ear tag numbers. If the animal was tagged with a visual (non-electronic) eartag, there is no centralized tag distribution database and obtaining records often requires a lengthier search and further verification.

This final rule does not require producers or livestock markets to have electronic reading equipment or additional data management systems, because the official electronic ID tags must be readable visually as well as electronically. It is important to remember that producers should not sell, loan, or give tags they have purchased to other producers, because all 840 ID tags they have purchased are recorded as being distributed to them using the location identification system (Premise ID) used by their State. APHIS maintains an Animal Disease Traceability webpage with direct access to the Final Rule, FAQs, how to obtain free electronic ID tags, and other resources at https://www.aphis.usda.gov/livestock-poultry-disease/traceability .

RFID tags were previously categorized as either “Low Frequency” (LF) or “Ultra-High Frequency” (UHF). This final rule now uses the acronym “EID” instead of “RFID” and refers to EID tags as “HDX” or “FDX”. What happened?

The new rule refers to electronic identification (EID) tags rather than radio frequency identification (RFID) tags to recognize the possibility of other electronically readable technology that may become available in the future. Electronic eartag technology can be categorized by the way information is transferred between the tag and reader, either “Half Duplex” (HDX) or “Full Duplex” (FDX). HDX tags are heavier, they transmit information one way at a time, they are better able to transmit through interference such as metal objects, they have the strongest read range, and are slightly more expensive than FDX. FDX eartags are lighter in weight, they transmit information continuously but are more susceptible to interference from metal objects and fluorescent lights, and they have a shorter read range. Both technologies work well and have similar qualities but have different strengths and capabilities so the choice depends on where and how it will be used (see Figure 1). Regardless of type, all electronic ID tags must be approved by USDA and meet standards for quality and performance, be tamper proof, contain a unique ID, the words “Unlawful to Remove” and display the U.S. official eartag shield. Both HDX and FDX tags follow the ISO standard and can be read by the same readers.

Figure 1

HDX tags talk to the reader like a 2-way radio; the reader sends out a signal then the tag replies. A half-duplex RFID reader generates short magnetic pulses that wirelessly charge a capacitor inside an HDX tag. When the charge field turns off, the tag uses the stored power to send the tag number back to the reader without interference from the reader. HDX uses Frequency Shift Keying (FM) which has better noise immunity and allows larger, simpler antennas. Since the charge field is pulsed, HDX readers require less power. Half Duplex (HDX) tags are (generally) white in color. They are better suited to transmit through metal interference such as metal and steel objects. Typical read range on HDX tags ranges from 15″ – 18″.

FDX is like a phone conversation: as soon as the tag receives the reader signal both tag and reader talk simultaneously. A full duplex RFID reader generates a continuous magnetic field which powers the tag to respond immediately. Tags repeat their message while powered by the field, up to 30 times per second. FDX tags can be made very small and thin due to their simple construction of a coil, ferrite rod and a chip. Very small tags have a short read range and so are primarily used for hand scanning. FDX uses Amplitude Shift Keying (AM) and is susceptible to atmospheric noise which limits antenna sizes. Full Duplex (FDX) are (generally) yellow in color and are good when the read range is short (13″ – 16″). FDX tags are more susceptible to interference from metal and steel objects such as head gates, panels, and squeeze chutes as well as fluorescent lights.

What is the difference in cost between HDX and FDX tags?
The cost of EID official identification tags varies by tag type and quantity purchased. USDA performed a market analysis in 2022 and found the cost per FDX tag ranged from $2.00 for large quantities (5,000 more) to $3.45 for smaller quantities (20 tags). The advertised retail price per HDX tag in August 2022 ranged from $2.32 for large quantities (5,000 or more) to $3.65 for small quantities (20 tags).

Depending on the tag type, many vendors that handle official ID tags offer volume discounts and free shipping for large orders.

When shopping for USDA-approved tags, manufacturers offer “visual tags”, “RFID tags” (FDX and HDX), and “RFID with visual matched (paired) sets”. Are “visual” tags with no electronic or RFID component still official?

The minimum identification standard in cattle is the visual 840 tag. For visual-only tags, the entire official identification number must be imprinted on the portion of the tag inside the animal’s ear. This will suffice if the cattle never leave the state of origin within their lifetime, however, interstate travel requires a tag with electronic capabilities. For electronic ID tags, the entire 15-digit official identification number beginning with 840 must be imprinted on the portion of the tag containing the transponder (see Figure 2). Be aware that manufacturers still sell tags beginning with 900 numbers used for in-herd data use only and cannot be used as Official ID.

Figure 2

Many of the new tags display a data matrix; what comes up when scanned with a cell phone?
The 2D Data Matrix that conforms with the ECC200 Data Matrix protocol must be imprinted on the portion of the tag that contains the transponder in a square approximately 5mm x 5mm and should be a two-dimensional representation of the official animal number imprinted on the tag. Readability (percent of data matrix read) on new tags being shipped from the manufacturing plant must be at 100 percent when read with a camera-based image reader (bar code reader).

Where should official electronic ID tags be placed?
The EID tag may be placed in either ear although the left ear is preferred. The tag should be placed in the middle of the ear, approximately ¼ to 1/3 the distance from the head to the outside tip of the ear and between the two cartilage ribs (see Figure 3). Make sure and record the date the tag was applied and a description of the animal. Accurate records of tags received and applied are required to be kept for a minimum of 5 years after the animal has been sold or dies.

Figure 3

Has anything changed with this new rule regarding which cattle are required to have “official identification” when moving interstate?
No changes have been made with this new rule. For cattle, the following animal classes must be identified with official ID eartags, both visually and electronically readable, beginning November 5, 2024, when moving interstate:

• All sexually intact cattle and bison 18 months of age or over.
• Cattle and bison of any age used for rodeo, shows, exhibition, and recreational events.
• All dairy cattle, regardless of age or sex or current use.
• All offspring of dairy cattle, including Beef on Dairy cross bred cattle.

The requirement for individual identification does not include beef feeder cattle, nor any cattle or bison moving directly to slaughter.