Ask the Vet

Dr. Ken McMillan, Contributing Columnist

READER: We sold some pairs recently, and our veterinarian said we had to have electronic ID (EID) tags in every animal for the health certificate. We did not have to do this last year. When did this become required?

DR. McMILLAN: There was a significant rule change by the USDA that took effect Nov. 5, 2024. After this date, official ear tags for almost all cattle and bison must be both visually and electronically readable. The rule's goals, according to the USDA, are "to enhance disease traceback, limit the spread of devastating diseases and provide information needed for foreign countries to recognize disease-free regions."

While some producers have concerns over this rule, I have long worried that we don't have a good animal disease traceability system anymore. At the peak of the brucellosis and tuberculosis eradication program, almost every cow had an official ID that traced back to the farm of origin -- the old reliable silver or orange metal tag.

The new USDA rule applies to:

-- all sexually intact cattle and bison 18 months or older

-- all dairy cattle

-- cattle and bison of any age used for rodeo or recreation events

-- cattle or bison of any age used for shows or exhibitions.

States may set stricter standards, however. Wisconsin, for example, requires official ID for all cattle and bison except beef steers. Michigan has had electronic identification tag rules in place for several years.

The tags must:

-- be approved by the USDA

-- meet quality and performance standards

-- be tamper proof

-- contain a unique ID

-- display the U.S. official ear tag shield.

The only tags that meet federal requirements are AIN (Animal Identification Number) ear tags commonly known as "840" tags. AIN tags begin with the official country code ("840" for the U.S.) followed by 12 digits. With some of these tags, the EID part is the button back for the visual tag, but I prefer a visible tag and a separate EID button, since the button is much less likely to be lost than a visual tag.

Shearwell Data has a new EID tag similar to the old metal ear clips. I have never used these tags, but I am very interested in hearing from anyone who has experience -- either good or bad -- with them.

READER: We are having issues with EID tags. We have lost several and have had some of the buttons get infected and had to be removed. Do you have any suggestions to prevent this? What do we need to do if a tag is lost?

DR. McMILLAN: The first step to prevent both infection and tag loss is proper technique. Always clean the ears with a disinfectant such as chlorhexidine. Proper placement is critical. Both tags and button backs should be placed between the two cartilage ridges in the center of the ear. If using a separate visual tag and EID button as I recommend, the tag should be about halfway between the head and the tip of the ear. The button should be placed closer to the head. Make sure you have the right tagger and the correct pin for the tags you are using. Just because the button back goes on the pin does not mean it's a match. The wrong pin may damage the shaft or may not seat it correctly into the tag.

If tags are properly placed, the most common correctable reasons for tag loss are not removing twine or net wrap from hay bales, heavy brush or small trees on which the tags can get caught. Always remove twine and net wrap.

For more information on proper ear-tagging, I recommend the Canadian Cattle Identification Agency website at https://retentionmatters.ca/…

One thing I wish our industry and the USDA would work to develop is microchips for permanent identification combined with a visual tag. I have personally implanted thousands of microchips in pets with no issues. We have an operation that uses goats, donkeys, sheep, pigs, rabbits and mice to produce antibodies for use in human and veterinary medicine. They are all "chipped," and we have never had an issue with a lost or migrated tag in the 17 years I have worked with them.

If you lose an EID tag, I recommend calling your state veterinarian's office to ask for help.

**

-- Please contact your veterinarian with questions pertaining to the health of your herd. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.

-- These are only my thoughts and general guidelines. Please get with your veterinarian and together develop the best program for your herd.

-- Email Dr. Ken McMillan at vet@dtn.com

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