The invention relates to a cattle marking and identification ear tag of the type that combines a male part and a female part, including a tag (2) and an essentially cylindrical or frusto-conical button (3) which is secured to an eyelet (4) in the tag, such that the base (5) of the button abuts against the edge of the eyelet, the contact surfaces having a complementary shape. The ear tag is characterized in that the base of the button includes at least one reinforcing rib (6). The button is provided with reinforcing elements such that the tag cannot be detached from the button at the eyelet using a cutting instrument without leaving visible traces of attempted forgery of the tag.
