Another North Canterbury dairy farm has been confirmed to be infected with Mycoplasma bovis. The Ministry for Primary Industries says the farm is connected to known infected farms through animal movements. Tracing work from this farm was under way.

MPI said in its latest stakeholder update last night that four previously infected farms have had their IP (infected property) status lifted. One Canterbury and three Southland farms were depopulated, decontaminated and have completed a 60-day stand-down period. MPI's Recovery Team would help the farms to return to normal operations.

The number of currently active IPs stands at 38. These are made up of 18 beef farms, 17 dairy farms and three lifestyle properties. A total of 173 properties that were previously under movement controls from MPI have tested negative and had the controls lifted.

MPI Incident Controller for M. bovis Catherine Duthie spoke earlier yesterday to The Country's Jamie Mackay about the numbers, saying MPI is "getting to the front of the infection."

"Those properties that have recently become infected properties, and we've had two in the last week, they've been infected only recently, so we have hope that we're getting to the front of the infection and that we're catching up with it."

Duthie says she expects to see a decrease in the number of infected properties as the response continues, although it is possible there could be a slight increase once spring milk testing gets underway.

"We do expect to see a little bit of an increase," says Duthie, "but we're hoping that it's not going to be too much. We're cautiously optimistic the numbers won't increase dramatically."

MPI has had to deal with negativity from the farming community for its handling of the Mycoplasma bovis response, but Duthie says the Ministry has responded to this criticism.

"We're now a year into this and we're switching to little bit more of a farmer-centric approach to this."

Duthie adds that MPI recently held a meeting in Wellington with affected farmers, "where we invited people who have been impacted by us at various stages in this response to come and give us some feedback on what we could do better."

"We're really trying to interact with everybody on a personal level, we welcome feedback on what we could be doing better."

MPI's testing shows that Mycoplasma bovis has been in New Zealand since 2015, yet some people speculate the cattle disease has been here a lot longer. Duthie disagrees with this theory.

"The information from these other people seems to be coming from visible symptoms on-farm and it should be noted you can not diagnose Mycoplasma bovis by visual symptoms alone. It needs to be confirmed with that DNA testing."