N.C. Gen. Stat. § 80-45

Every person who has any horses, cattle, hogs or sheep may have an earmark or brand different from the earmark or brand of all other persons, which he shall record with the clerk of the board of commissioners of the county where his horses, cattle, hogs or sheep are; and he may brand all horses 18 months old and upwards with the said brand, and earmark all his hogs and sheep six months old and upwards with the said earmark; and earmark or brand all his cattle 12 months old and upwards; and if any dispute shall arise about any earmark or brand, the same shall be decided by the record thereof.