Recent Outbreak in Canterbury
A dairy farm in Canterbury has been reported as the latest to be infected with Mycoplasma bovis, marking it as the second property in the region to be affected by this disease. The Ministry for Primary Industries (MPI) has indicated that such further infections towards the end of an outbreak are not unusual, and it had been anticipated that more properties might be discovered.
Depopulation and Disinfection Measures
The MPI has outlined that depopulation, cleaning, disinfection, and a 60-day stand-down period for the Active Confirmed Properties are expected to be completed in early 2024.
This follows the infection of another dairy farm in Selwyn, Canterbury, which was confirmed in September and identified through standard Bulk Tank Milk background screening after several months without infection.
Investigation and Strain Identification
The newly infected farm, which neighbours the previously affected property, was identified following routine testing. Initial indications suggest that the strain of this infection is ST-21, the same strain first detected in 2017 and associated with most recent infections.
The source of the infection for the new property is currently unknown.
Movement Restrictions and Risk Mitigation
The affected property has been under movement restrictions for several weeks, and these conditions have now been further strengthened. The MPI is working closely with the farmer to trace animal movements on and off the farm and other risk events. This tracing is expected to result in an increased number of farms under movement restrictions as efforts to mitigate the risk of disease spread continue.
Importance of Biosecurity and record-keeping
The MPI emphasises the importance of farmers adhering to good biosecurity practices and recording all cattle movements onto and off their farms. Accurate and up-to-date National Animal Identification and Tracing (NAIT) records are crucial for tracing animals and are the best defence against the spread of Mycoplasma bovis.
Ongoing Efforts and Surveillance
Despite the decrease in infection cases each year, the MPI, alongside industry partners Beef + Lamb NZ and DairyNZ, continues to make significant progress in managing the disease.
The number of infected properties has fallen to very low levels, and the MPI expects that in the coming years, the major activity of the programme will be the national surveillance of New Zealand’s cattle herd.
