Testing for Mycoplasma Bovis stepped up with new strain

Summer testing for Mycoplasma bovis will be stepped up after New Zealand’s nationwide surveillance programme identified a new strain of the disease on one of the 4 confirmed positive properties, which are all in Mid Canterbury, says M. bovis programme director Simon Andrew.

Mr Andrew said recently completed genomic testing from a single property, which was previously confirmed with M.bovis, had identified the strain.

"This strain doesn’t behave any differently than the strain we have been dealing with, and our existing testing will pick it up, as it has done in this case. It doesn’t affect our efforts to eradicate M. bovis from New Zealand."

Mr Andrew said a thorough investigation was under way into historic pathways, which included 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.

"The bulk tank milk and beef herd screening (alongside our cattle tracing work) has 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.

"We have a national testing regime to find infection, which we didn’t when M. bovis was first found in 2017. M. bovis is currently on just 4 farms compared to 40 at the height of the programme.

"It is important farmers know we are 4 years into a 10-year programme, and we remain 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 our investigation into pathways reveals that further action is required, including targeted testing and surveillance on-farm, we will let farmers know, but at this stage the increased frequency of summer bulk tank milk testing, beef surveillance and tracing animals will serve us well.

"We thank farmers and our sector partners, Dairy NZ and Beef and Lamb New Zealand, for their continued vigilance as we work toward eradication," Mr Andrew says.

"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.

Update from DairyNZ

What we know so far

The discovery of a new strain was made through regular bulk milk tank testing, which is evidence our highly sensitive system is working well. MPI will continue with fortnightly bulk milk tank testing over the summer months, to ensure any evidence of ongoing infection is picked up.

MPI are investigating historic pathways to identify the source of this new strain, which includes looking at recorded and unrecorded animal movements since 2018, imported feed and farm machinery, and imported frozen semen.

While considered a very low risk, the frozen semen used on the affected property had been imported prior to the new import health standard (introduced April 2022) and is a focus of their investigation.

What to do

Until we know the source, it’s business as usual.

Continue to practice good farm biosecurity and be vigilant with NAIT records. If you have a biosecurity question, call the MPI hotline, 0800 00 83 33.

If you need on-farm support or advice, please do contact our regional team