Four new South Island farms have been confirmed as infected with the cattle disease Mycoplasma bovis.
Photo: RNZ
They are near Tapanui, Waimate, Invercargill and Darfield.
That brings the total number of actively infected farms to 42.
Meanwhile, eradicating this disease could cost more than was first thought, according to advice provided to the cabinet.
The government decided on 28 May that it would try to eradicate the disease over a 10 year period.
It said that would cost $886 million.
By contrast, doing nothing would cost $1.15 billion.
However, the cabinet paper that informed their decision has been released.
It suggested that figure might not be the final word.
It said some infections would probably not be tested in the tracing process.
As a result, the number of infected farms might be under-estimated and so the final cost of the disease might have to revised upwards.
The paper also confirmed the decision to try to eradicate the cattle disease Mycoplasma bovis was done in hope rather than certainty.
When ministers made the decision to eradicate, they stressed that it was a difficult choice to make but they had to give it a go.
The cabinet paper said success could not be guaranteed.
Moreover, an independent technical advisory group was only narrowly in favour of some sort of eradication - by six members to four.
In addition, the cost of eradication could be wasted if the scheme failed.
Many of these points were acknowledged when government ministers' decision to eradicate was made.
But they stressed at the time it would be wrong not to at least try to get rid of the disease.
Regarding the spread of the disease, the Ministry for Primary Industries has published these figures:
- Hawke's Bay (Hastings) - 2 (1 active)
- Manawatū (Pahiatua) - 1 (1 active)
- Waikato (Cambridge) - 2 (2 active)
- Wairarapa - 1 (1 active)
- Canterbury - 21 (17 active)
- Otago - 8 (5 active)
- Southland - 17 (15 active)