A new strain of Mycoplasma bovis has been identified on a mid-Canterbury farm, the Ministry for Primary Industries says.
M bovis programme director Simon Andrew said the new strain was identified through genomic testing.
The strain was one that already existed overseas but had to date not been found in New Zealand, he said.
The strain had a different genetic footprint than the dominant strain in New Zealand, but behaved the same, he said.
Existing testing methods would pick it up if it spread, Andrew said.
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Because the strain already existed overseas it likely entered New Zealand undetected, he said.
The strain’s historic pathways, which included recorded and unrecorded animal movements dating back to 2018, imported feed and farm machinery, were being investigated, he said.
Frozen bull semen was used on the property, and although it was very low risk it was imported before the strict biosecurity measures that was used today, and would also be investigated, Andrew said.
There was no evidence the new strain spread to any other farms, as bulk tank milk and beef herd screening had not identified the strain anywhere else, he said.
M bovis was identified on a new property late September, with the farm being depopulated.
Depopulation could mean culling or the permitted removal of animals, he said.
An M bovis infection affected animals at herd level, unlike other cattle diseases such as tuberculosis that could be found in one animal only. Therefore, if a herd was confirmed to be infected the whole herd would be culled, Andrew said.
Last month new measures to tackle M bovis were announced. At that stage there were 20 farms under direction. That compared to more than 300 at the programme’s peak in earlier years, Andrew said.
Properties under notice of direction could not move animals off-farm until testing was completed and clear results returned. Most farms under a notice of direction returned a negative result and were able to then farm as normal, Andrew said.
There were four infected properties in total, all in Mid-Canterbury, Andrew said.
To date 178,000 cows had been culled under the M Bovis eradication programme. In June this year the total costs of the programme was $588m.
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