Farmers are getting a double tagging message from the Animal Health Board, as they move closer to the national animal identification and tracing scheme taking effect.
From July, it will be compulsory for cattle to have radio frequency identification ear tags.
From March next year, that will be extended to deer.
As part of the changeover, farmers will no longer have to place Animal Health Board approved secondary ear tags on cattle and deer, to help keep track of stock movement for Bovine Tb control.
Animal Health Board operational policy manager Nick Hancox says removing the need for secondary tags will rationalise the tagging process and keep costs down.
But he says during the changeover, farmers need to leave existing official ear tags on their stock.
Mr Hancock says in many cases, the old tag will still be the only link back to the herd of origin.
He says the need for double tagging will eventually go away as animals are tagged under the new system from birth.