http://www.maf.govt.nz/quarantine/an...ucts/index.htm
I would suspect that you are fine bringing them, though possibly as a worse case scenario they may have to be treated as they may be classed as animal skin products. Which if you follow the link says they are allowed in after treatment.
However in practice they are likely to get chucked in a box with other stuff and marked as "kitchen stuff" and maf won't be interested in the slightest