Andrew said a thorough investigation was underway into historic pathways, which include recorded and unrecorded animal movements dating back to 2018, imported feed and farm machinery, and frozen semen imported prior to the tightening of import health standards for bovine germplasm.
"While considered a very low risk, frozen semen used on the affected property, which had been imported prior to the introduction of the new import health standard, is being looked at.
"Our team is carrying out an investigation on the affected property. At this stage, there is no evidence to suggest that there has been any forward spread on any farms that received cattle from this farm."
Andrew said bulk tank milk and beef herd screening (alongside cattle tracing work) had not identified this strain anywhere else.
"But disease control is all about being cautious, so we will be increasing the summer frequency of our national bulk milk surveillance testing from once a month to every fortnight, as we do over spring."
There was now a national testing regime to find infection, which wasn't available when M. bovis was first found in 2017, Andrew said.
M. bovis is currently on just four farms compared to 40 at the height of the programme.
Andrew said it was important for farmers to know MPI was four years into a 10-year programme and remained on track for eradication.
"We are moving towards a national pest management plan for M. bovis much like that used for TB. The aim of that will be to monitor and deal with any disease that pops up over time."
If the investigation into pathways revealed that further action was required, including targeted testing and surveillance on-farm, MPI would let farmers know, Andrew said.
"But at this stage, the increased frequency of summer bulk tank milk testing, beef surveillance and tracing animals will serve us well."
Andrew thanked farmers and sector partners, Dairy NZ and Beef + Lamb NZ, for their continued vigilance.
"It was estimated that the cost of M.bovis to farmers would be $1.3 billion over 10 years, and much higher if it became endemic."
Farmers with any concerns can call 0800 00 83 33 or email info@mpi.govt.nz.
Eradicating M. bovis:
The Mycoplasma bovis Eradication Programme began in May 2018 and is jointly funded by Government (68 per cent) and DairyNZ and Beef + Lamb New Zealand (32 per cent).
Since M.bovis was discovered in 2017, a total of 276 properties have tested positive for the disease, and nearly 3 million tests have been completed.
In terms of compensation, $231 million has been paid out in 2795 claims.
The cost of the Programme, as of June 30, 2022, stands at $588m, and a total of 178,000 cows have been culled to date.
