She said MPI's quarantine measures were very effective in containing the disease and mitigating its spread.
She responded to a call by Kaitaia dairy farmer Ian Walker for the ministry to name the infected farm so other farmers could take appropriate measures. But MPI said the call was causing needless worry to farmers whose farms were not at risk of being infected.
"Cattle grazing nearby who are not in prolonged and repeated physical contact with the infected farm are not at risk of infection."
The infected property in Northland is in quarantine lockdown to reduce the likelihood of the disease spreading. All infected cattle on the farm will ultimately be culled, in agreement with the farmer.
MPI is informing all immediate neighbours so they can take the necessary precautions to stop their cattle coming into contact with animals who may be carrying the infection.
"As naming the property has no implication to the wider public, other than immediate neighbours, MPI will not be identifying any properties who are infected with M. bovis until the property owner has decided to go public.
"This balances the privacy concerns of individuals with the need for farmers to protect their own farms and there is no intention to change this approach," the spokeswoman said.