Mycoplasma bovis farms confirmed in South

To date, more than 3500 animals have been culled as a result of Mycoplasma bovis. Photo / Lewis Gardner

Confirmation that four new properties have tested positive for Mycoplasma bovis is "not good news", the Ministry for Primary Industries says.

Three were within a farming enterprise in Winton, in Southland, one was near Hastings, and the ministry strongly suspects a further property near Ashburton.

In a statement yesterday, the ministry's director of response, Geoff Gwyn, said early indications were all the properties had links with Van Leeuwen Dairy Group — where the disease was first detected — through cattle movements.

MPI's director of response, Geoff Gwyn. Photo / File

To date, more than 3500 animals have been culled as a result of the disease and the depopulation programme on the infected VLDG properties was on track to be completed before Christmas.

The ministry was still analysing what the new developments meant for the wider response.

"We're dealing with a lot of uncertainty. Our investigators are building a picture of stock movements on to and off these farms so we will not be making hasty decisions on next steps," he said.

Although it was "really disappointing" to have the new properties, it was not totally unexpected. The disease was spread through contact between animals and through stock movement. It was always possible further infected properties would be found as buying, selling and moving stock was a common practice. Tracing animals and their movements was "complex detective work" which took time.

The Hastings and Ashburton properties were identified through the ministry's tracing programme and the Winton property was identified through the industry milk testing programme.

All the movements were before July 21, when the disease was first detected and notified to MPI.

The Hastings and Winton properties were placed under a Restricted Place Notice, effectively placing them in quarantine, while the suspect property was under voluntary movement controls until its status was confirmed.

Federated Farmers president Katie Milne said the rural lobby organisation and other industry leaders remained committed to eradicating the disease even though yesterday's announcement made that a "bigger but by no means impossible challenge" to overcome.

Agriculture and Biosecurity Minister Damien O'Connor was "deeply disappointed" by the latest news.

Officials were working hard to track the disease. They were still unable to identify its source and that concerned him.