Reactor cattle and bison shall be identified by branding the letter "T" on the tail head, not less than two (2) inches wide, nor less than three (3) inches high, and by tagging with an approved metal eartag bearing a serial number and inscription US reactor, or a similar state approved reactor tag suitably attached to the left ear of each animal. Reactor goats shall be identified by tagging with an approved metal eartag bearing a serial number and inscription US reactor, or a similar state approved reactor tag suitably attached to the left ear of each animal.
Okla. Admin. Code § 35:15-40-44