Farm animal identification

Although most farmers don’t name every animal they have, knowing which animal is which is still very important. Farmers use ear tags like these to identify individual animals in a herd where one animal looks very much like another.

calf with ear tags

Ear tags and other forms of identification are also very important when it comes to the sale and transport of farm animals. Farmers and veterinarians need to be able to keep track of which animals are sold or transported to other farms or to processing facilities. This becomes especially important if there is an outbreak of disease in farm animals. The Animal and Plant Health Inspection Service (APHIS, a division of the United States Department of Agriculture) has recently released revisions to its rule on animal disease traceability.

Why is farm animal traceability important?

It is essential that farmers, veterinarians, and public health officials can identify which animals have recently been transported from one farm to another or from a farm to a processing facility. If that animal is found to be sick, they can trace the animal’s path back and find any other animals it may have come into contact with and potentially exposed to a disease. The veterinarians can then determine if those animals need to be tested, treated, or even quarantined to prevent further spread of disease. While this is one more step the farmer must take, and one more round of paperwork that must be maintained, this is a very important step in securing the safety of our food supply.

What kind of identification do animals need?

All animals must have a health certificate, or certificate of veterinary inspection, before they travel across state lines. This is a form that verifies that a veterinarian examined the animal (or group of animals) and did not find any outward sign of disease before they left their “home” farm. Some states require additional blood tests before letting animals into the state. These tests must be done before the animal leaves and the results recorded on the health certificate.

In addition to a health certificate, each animal also needs identification. The type of identification that is required is different for different species. Cattle need to have an official USDA-issued ear tag, or a brand or tattoo that is registered with their breed organization. The registration paperwork for the brand or tattoo must travel with the animals.

Pigs can have an official ear tag, an official back tag (sticker), a tattoo, or ear notches as their identification. Many farmers raise pigs in groups – they are born and raised on the same farm, and are never mixed with pigs from outside their group. Pigs in these types of closed groups do not need individual identification, but do need group identification.

Sheep and goats are typically identified as a flock or group. There is a program in the United States that certifies sheep and goats as “scrapie-free” (the National Scrapie Eradication Program). (Scrapie is a brain disease similar to bovine spongiform encephalopathy that can affect sheep and goats.) For farms participating in the scrapie program, these tags are sufficient identification. Otherwise, sheep and goats need an official ear tag, a back tag, an official breed registry tattoo (with registration paperwork), or a premises identification tag with a unique animal identification number.

Finally, poultry need to have leg bands with their individual identification number, or a group identification number if the birds have been raised and kept together their entire lives.

What does this mean to me at the grocery store?

The main purpose of this nationwide animal identification program is to help us monitor animal health. Without individual animal identification, it can be very difficult to find all the cattle that one sick cow may have exposed to a disease (cattle are often sold to more than one owner and come into contact with many other cattle during their lives). With this tracing program, officials will be able to quickly identify any animals that might have been exposed to a disease and determine the best way to prevent more from getting sick (testing, treatment, or quarantine).

Although animal health is the primary reason for this program, this does also affect food safety and supply. In the case of a serious disease outbreak, this program will allow veterinarians and food safety officials to rapidly identify and segregate sick or exposed animals. This helps us to control the spread of animal disease, and ensures that only healthy animals are entering our food supply.


Large animal veterinarian, cattle farmer, pet owner, grocery buyer.

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