In a first for the Mycoplasma bovis eradication programme, high-quality farm records have enabled an active confirmed property to be cleared without the need to depopulate the entire herd.
OSPRI general manager disease control planning and integration Simon Andrew said the completeness of the farm records combined with the early detection of the infection, two rounds of negative results from on-farm testing of the dairy herd and the regular non-detect results being received from the background Bulk Tank Milk (BTM) screening programme enabled the M bovis programme to avoid the need to depopulate the whole herd.
“The now-cleared confirmed property has very good records on cattle movements, which has helped our work,” Andrew said.
In many cases, especially in the initial years of the eradication effort, the M bovis programme was chasing infection that had been established for some time.
“Now, we are in the tail of the epidemic curve with significant background and network surveillance underway.
“We are finding infection earlier than before and the investigation into this farm indicates M bovishad been introduced recently and was identified before it spread to all groups of cattle on the farm.”
The remaining cattle will continue to be subject to on-farm testing over the next few weeks, as it is a neighbour of the one remaining active confirmed property.
The dairy herd, like others nationwide, will also continue to be screened as part of the BTM background surveillance.
If any risk of infection becomes apparent, the programme will take steps to contain it, as with any other farm.
Andrew said this outcome is not always possible, and the standard of the available records played a key role.
“Not only was the infection confirmed to be isolated to the management group, but the high quality of the animal movement records also reduced the need for manual tracing, which can be time intensive.”
In contrast, cases with poor records require a more cautious approach to be taken, with a higher impact and disruption to farmers.
At best, this means testing more farms than would otherwise be necessary, and at worst, infection spreads unchecked, resulting in increased disruption and stress for farmers, delays in reaching eradication and significant increase in time and cost.
Andrew said it is important that farmers recognise M bovisstill poses a risk and that they play a critical role in supporting the eradication effort.
“The best thing farmers can do to protect the progress made is to ensure good NAIT records are maintained along with other records about movements of cattle within the property.”
New Zealand cattle farming is unique with a high number of animal movements. In a single day, there can be thousands of cattle movements between properties.
“As the highest risk of M bovisspread between farms is from the movement of infected animals, we rely on farm records and the NAIT system to help us to identify where the disease may have spread to, and where it came from.”
To complement the tracing work undertaken, the BTM and beef and drystock national surveillance screening programmes are continuing to run in the background each day.
“These give us crucial information about the presence of M bovisin NZ and will continue for several years.”
NAIT data is continuing to improve, indicating more farmers are fulfilling their obligations.
Andrew reminded farmers they play a critical role in building useful animal traceability.
Keeping accurate NAIT records means fulfilling five key obligations under the NAIT Act.
• Registering as a Person in Charge of Animals (PICA): If you are the main person in day-to-day charge of NAIT animals you must register as a PICA in the NAIT Information System.
• Registering your NAIT location: If you have NAIT animals on a property you manage you must register the location in the NAIT Information System.
• Tagging and registering your animals: You must apply NAIT ear tags to your NAIT animals within 180 days of birth, or before the animals are moved to a different location, whichever comes first.
• Recording animal movements: If you are sending from, or receiving animals to, your NAIT location you must record the movement with 48 hours.
• Keep NAIT up to date: Declare any animals that are missing or dead in the NAIT information system and keep your NAIT information up to date.
Meanwhile the number of Active Confirmed M bovis properties currently sits at one, being a Canterbury dairy property.
A further four properties are under Notice of Direction with 35 active surveillance properties.
To date a total 189,666 cattle have been culled and $271.5 million paid out in compensation across 2943 claims, with 12 claims currently in progress.