The Government has admitted eradicating cattle disease mycoplasma bovis is no longer a short-term goal.
Agriculture Minister Damien O'Connor told Newshub Nation a "hell of a lot" of cows are now affected by the Mycoplasma bovis outbreak.
As of Saturday, the disease had been confirmed on 38 farms across Southland, Otago, Canterbury, Hawkes' Bay and Manawatu.
- First north Canterbury farm confirmed to have mycoplasma bovis
- 22,000 mycoplasma bovis-infected cattle to be culled
"The scope of the infection is a lot wider than the original modelling that we had. The situation is worse than we thought it was.
"There are also up to 70-plus farms that are likely to be infected. We've got hundreds under investigation - up to 300 - and then we've got up to 1700 that are of interest. At the moment, we're halfway through the process of culling 22,000 [cows], and there's up to 60,000 potentially in those affected properties already identified. So the numbers are very, very big."
While the Government is "still aiming" for eradication, Mr O'Connor says the situation is changing constantly.
"As we do more research, more tracking, identify more properties… Then, clearly, the balance of probability changes.
"The chance of rapid eradication is almost gone. The chance of long-term eradication is still possible. We're not at the point where we're saying we can't."
Mycoplasma bovis does not infect humans and is not a food safety risk. However it's devastating for livestock, causing mastitis, pneumonia, arthritis and late-term abortions in cattle.
On Wednesday the disease was detected on a mixed sheep and beef farm in north Canterbury - the first confirmed case in the region.
Ministry for Primary Industries (MPI) Mycoplasma bovis response incident controller Catherine Duthie says the discovery of new infected properties is not because the disease is spreading.
"All the infected farms we know about are in quarantine lockdown and no movements of risk goods, including animals, are allowed off them.
"Rather, the new finds are the result of our tracing uncovering historical movements of animals and then confirming the infection through testing. These movements, in many cases, took place before we even knew Mycoplasma bovis was in the country."
Mr O'Connor says 70 percent of farmers were not tracing cattle movements properly through the National Animal Identification and Tracing (NAIT) system. Some farmers have also been trading cows for goods and services on a black market - making it even harder to know where infected cows may have ended up.
"It's hard to identify how widespread that [the black market] is but it's something that has been exposed by this unfortunate incident"
MPI is now deciding whether Moving Day - where thousands of sharemilkers move stock to new farms - can still go ahead on June 1.
"We've always been attempting to be in a position to make a clear call prior to the end of May. But any infected place, any infected farm, will not be able to shift stock. That's a restriction on them now. In terms of other farms, we just hope farmers take a sensible approach to this.
"We're getting all the advice that we possibly can and hopefully we can make the right decision - not just for farmers now, but for farming moving into the future."
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