The Ministry for Primary Industries has identified eight farms in Northland which may pose a risk of spreading cattle disease Mycoplasma bovis.
The farms have been issued with Notices of Direction (NoD) which means MPI believes taking stock and other risk goods from a property could spread M. bovis.
MPI would not say where the eight farms were located or when the NoDs were issued, citing privacy reasons. The NoD aims to prevent further spread and doesn't restrict movement of stock or goods on to the farm.
Cattle could only be moved off the farm with a permit. Other steps such as disinfecting and cleaning of vehicles may be required to and from the eight farms.
So far, only one farm in the region has tested positive for the bacterial disease and some of the herd of 50 cattle has been sent to the slaughterhouse.
The dry stock beef farm is located just east of Dargaville.
A Northland Regional Council biosecurity incursion management officer is working with MPI to ensure all precautionary measures are taken on the eight farms. A further eight farms have had their NoD revoked after tests for M. bovis.
An MPI spokesman said a NoD was issued to farms when an inspector or authorised person considered that movement of stock or other risk goods from a property posed a risk of spreading M. bovis.
That could be when animals from infected properties have been moved to there but testing had not taken place or when results were pending.
He said NoDs were also issued when specific directions needed to be given, such as culling of stock.
"It is important to note the clear majority of properties under a Notice of Direction do not end up testing positive for Mycoplasma bovis."
Sometimes, MPI may issue a transitional NoD if the ministry wants to lock down an infected farm, or one that is highly likely to be infected, while an assessment is made if it's possible to target or exclude areas or stock for a Restricted Place Notice.
That notice prohibits all unauthorised movements of farm stock and other risk goods on to and off the property in order to minimise the chance of the disease spreading from the property.
"Farms with strong biosecurity practices, able to keep mobs separate, and with excellent record-keeping, are more likely to be able to have only parts of their farm put under a RP and their farms partially depopulated," the spokesman said.