The agency running the new national animal identification and traceability (NAIT) scheme says it's had no indication that more farmers are being injured while trying to tag their cattle to comply with the scheme.
Introduced earlier this year, NAIT requires cattle to wear new radio frequency eartags so that individual animals can be electronically identified and tracked.
Livestock are normally tagged when they are young.
A critic of the scheme, Northland farmer Hugh Rose, says he's getting reports of farmers being hurt while tagging adult cattle.
The NAIT company's chief executive, Russell Burnard, says it has recognised the increased risk of tagging adult cattle and has made allowances for that.
Mr Rose also says people are already finding ways of undermining the scheme by recycling tags, something that's not meant to happen.
Mr Burnard says NAIT has had no indication of that happening, but would move quickly to stop it because it undermines the animal ID system.