Electronic identification (EID) tags for farm animals have been around for some time. Their primary function in a dairy context has been for cow identification in milking systems. Prior to 2013, EID tags could only be purchased as standalone tags. However, since 2013 it has been possible to buy EID tags as part of the official animal identification tag as per Department of Agriculture regulations.

Incorporating the EID tag into the official tag has reduced the cost of the EID tag and it has also meant that the number of the EID tag (the unique number picked up by electronic devices) is now the same as the official tag number that is registered to the animal. From a practical point of view, this has some advantages. For example, an electronic tag reader can now be used to identify and read the official tags. In theory at least, this could be used to identify animals in the event of an inspection. Of course, it can also be used to electronically identify animals for the farmers’ own benefit.