The rules already require the data. Make it useful.

Traceability used to mean a tag in the ear for the authorities. It now decides which animals can cross a border, which buyers will pay a premium, and how fast a disease event can be contained. The rules already require most of the data. The opportunity is to make it useful to the farm that produces it.

The United States: the EID rule

Since 5 November 2024, official ear tags applied for interstate movement must be both visually and electronically readable under USDA APHIS's animal disease traceability (ADT) rule. The rule covers all dairy cattle, including beef-on-dairy calves of any age, and sexually intact beef cattle 18 months and older. US official tags carry the country code 840 at the start of the 15-digit number.

Adoption outside dairy has been low. In the last national beef study, EID was used by 0.8% of cow-calf operations, while 90% of US milk comes from farms using individual cow records. Dairy is instrumented; beef and calves are mostly not.

Disease made it a market question

Recent events turned traceability from compliance into market access:

• New World screwworm. Southern-border cattle imports were closed in May 2025 for about 15 months. By 4 October 2026 there were 53 US animal cases (51 in Texas, 2 in New Mexico). The port at Douglas, Arizona reopened on 24 August 2026 under a joint protocol, and Texas now requires extra documentation and RFID for Mexican-origin cattle.
• H5N1 in dairy cattle. 917 herds were affected in 2024, 171 in 2025 and 93 so far in 2026, about 1,180 in total across 19 or more states. Wisconsin's first herd was confirmed in December 2025. Movement testing and herd status records are now routine paperwork.

When a border or a market can close overnight, the herds that can show where each animal has been move first.

Belgium and the Netherlands

EU bovines carry two ear tags under Regulation (EU) 2019/2035. Member states may allow an electronic identifier in place of one of them; EID is voluntary unless national rules require it, as in Ireland and Luxembourg.

• Belgium: register a calf in Sanitel within 7 days of birth. Belgium counted 2.13 million bovines in December 2025 (Eurostat), with country code 056.
• The Netherlands: report a calf to RVO I&R within 3 working days. The Netherlands counted 3.55 million bovines in May/June 2026 (Eurostat) and 964,000 veal calves in April 2025 (CBS), many imported from Germany, Ireland and Belgium. Country code 528.
• Movements between member states are certified through TRACES.

Disease pressure shapes movement decisions here too. Bluetongue BTV-3 reached more than 5,000 Dutch farms in 2023 and 8,063 in 2024, with 3,601 Belgian cases in 2024; Belgium made vaccination mandatory in 2025.

From required to useful

A registry entry tells the authority that an animal exists and where it is. It does not tell the farm anything new. The same identity, used as the key for the farm's own records, does:

• Movements recorded once and reported to the registry from the same entry, on time.
• Health status and vaccination attached to the animal, ready when a buyer or a border asks.
• Origin and age carried through every sale, which supports the records that verification programs audit. Age- and source-verified calves have been reported to earn $1 to $4/cwt more (Beef Magazine; UC Davis), though that premium requires an audited USDA program.

The chain of custody

Between birth and the rail, an animal can pass through a dairy, a calf raiser, a grower, a feedyard, several trucks and a packer. Every handoff is a chance to lose the record. A traceable system reads the EID at each one, checks the count against the paperwork, and records who received the animal and when. The result is a chain of custody the farm can show, not just a list of registry numbers.

Who sees what

Traceability data is also commercially sensitive. A farm's movement history reveals its buyers, suppliers and volumes. Good systems share with authorities what the law requires, share with buyers what the farm chooses, and default everything else to private. See ag data rights.

Rules and figures are from the sources named, as of October 2026. Check current APHIS, FAVV/AFSCA and RVO guidance before acting.