Two more properties, one in Southland and one in Waitaki, have been confirmed as infected with Mycoplasma bovis.
The announcement about the two additional infected properties was made last Thursday.
The same day, Minister for Agriculture and Rural Communities Damien O'Connor was in Southland, talking to farmers about the ongoing effort by the Ministry for Primary Industries (MPI) to trace the spread of the disease, contain it and then eradicate it.
Mr O'Connor talked about the efforts with M. bovis, including issues raised by farmers and vets about not being able to get in touch with MPI.
M. bovis is a bacterial disease that can cause serious conditions in cattle, including mastitis that does not respond to treatment, pneumonia, arthritis and late-term abortions.
''It had a devastating impact on cows and calves,'' Mr O'Connor said.
MPI was working to trace the spread of the disease.
''We are trying to work on a way of eradicating it if possible. I'm not even going to contemplate if not, because that should be the sole focus of everyone - to identify how far it has spread, then contain, and then eradicate if possible.''
It had already been identified that the Nait system had not worked as well as it should have, and this was something that was going to be addressed, Mr O'Connor said.
''Yes, it's a pain . . . at times, [but] we can't sell into high-value markets without a high system of traceability.''
Concerns were raised about how fast trace properties were being tested, as contracts were being drawn up at present for winter grazing and big beef deals were being made.
A case was brought up in which someone believed they had bought calves that were linked but could not get hold of MPI after four phone calls.
This was not good enough, he said.
Mr O'Connor encouraged them to make the fifth phone call, as every possible link needed to be known, he said.
''Every farm that we know if there is a possible link will be invaluable.''
Mr O'Connor had already publicly expressed his frustration with the Privacy Act, which meant farmers did not know where infected properties were.
''The privacy and exposure of properties, not to condemn people, but to assist with the traceability, has to be improved and I think identifying a property helps those who might be unfairly accused. It helps with clarity.
''In the end, it is actually about opening up the information so we can properly trace it.''
He assured those present that the point about the struggles with contacting MPI was being taken on board.
One farmer also raised the point that people needed to be reminded it was not just a dairy issue.
There was already a lot of stock movement going on, so everyone needed to work fast.
At present, all the infected properties, which were now 23 in total, were linked to the two source areas.
''We have to identify them pretty quickly,'' Mr O'Connor said.
Information on M. bovis is available on the MPI website.