The Zeestraten family, which owns Southern Centre Dairies, had been supportive of the response activity on its farms, Mr Gwyn said.
"This is a really tough time for them and I thank them for their ongoing co-operation. This is a situation that any farmer in New Zealand could find themselves in, so I encourage their community to continue to rally around them and give them support," he said.
Twenty-five properties had now been confirmed as infected, the most recent a dry stock grazing property in Southland, and 42 were under restricted-place notices.
North Otago Federated Farmers president Simon Williamson said there was a good turnout at an information evening in Twizel on Thursday, following confirmation of the disease in the area.
The purpose was to make people aware of measures they could take given calf sales were coming up and ensure they were keeping themselves safe and were aware of the issues. Rather than scare-mongering, knowledge was "everything", he said.
It was positive there appeared to be a commitment to get rid of the disease and there was a unanimous show of hands from those attending the meeting that they would be willing to contribute to a levy to help get rid of M. bovis.
A "real worry" for people, which would be followed up, was the likes of the Temuka saleyards and the need for them to be disinfected to prevent the disease being spread into beef herds, Mr Williamson said.
Farmers can call the MPI's confidential freephone 0800 809-966.