The Primary Industries Ministry has not said how it thinks the organism entered the country.
While speculation is rife that European-sourced semen is the most likely suspect, Biosecurity NZ head Roger Smith said investigations do not support that.
The M bovis strain has been confirmed as of European descent but is also occasionally found in America.
Smith is aware of infected property farmers who believe their only common link to M bovis is their semen supplier.
He confirmed M bovis bacteria has been found in semen.
“We have looked at that. We tried to grow it out but it was dead.”
He understood concern over the decision to continue eradication given the source had not been found.
“Under a normal response we would not eradicate if we did not know the import pathway but my level of confidence is that this is a one-off event, that just one activity happened that caused this incursion and that leads confidence it is not systemic.
“Our tracing is as close as we can get with all spread being animal movements.”
Based on science and risk assessment, Import Health Standards regulating the importation of semen and embryos are fit for purpose.
“We are continually revising this and will make adjustments if we find it’s necessary.”
Imported animal compounds and veterinary products have also been blamed as likely sources.
“Yep, initially that sounded pretty good but we looked at that in depth and right now with our level of knowledge we have seen no evidence of commercial importation of vet products through authorised channels.
“It has appeal but inquiry to date, no evidence, but that’s not to say some Joe Bloggs has not done something illegal.
“We are not God but I have a high level of confidence it’s not that.”
Smith said while all paths are deemed by scientists as low risk, one of them is the perpetrator.
“Because it had to come in some way. It was not an act of God.
“We will follow any evidence to the end of the earth as we all want to know but I expect we will end up with two smoking guns.”
Smith said charges were likely for acts relating to undeclared goods, miscleared goods and naming of products differently.
“As a result of the investigations there were some commercial imports found to be ‘not squeaky clean’ not necessarily related directly to the source but uncovered as a result of investigations.
He would not comment on the results of the searches of three premises in March.
“Investigations are still ongoing. This is still live in the sense that we haven’t closed the file,” Smith said.
He urged farmers under restrictions to make an acute recovery plan.
“Don’t get bogged with the long-term changes of farming when you are in the eye of the storm.
“MPI is saying you have got two weeks to get your farm management plans in and while MPI will outline the outcomes we want, we are encouraging you to design your own plan and get it approved by MPI. That way we can all move forward.”
Smith expects industry bodies such as DairyNZ, Beef + Lamb and Federated Farmers to rally around people not under MPI controls.
“I am mindful of those on the outer edge of the wave and this is where I expect industry to step up.
“How the farming community stands up now is how farmers will be perceived by urban people,” Smith said.
MPI will send out information, including details of the phased eradication plan, to farmers this week.
“It is our joy that some will open it – even read it.”
Last week three more infected properties were announced – a Wairarapa sheep and beef farm, a Ranfurly beef farm and a dairy farm near Ashburton.
