Wednesday, April 24, 2024

Back down to zero for M bovis

Avatar photo
Last known farm cleared – for now – as MPI turns focus on imported semen as a source of infection.
In May 2018, the government announced NZ would work to eradicate M bovis in partnership with DairyNZ and Beef + Lamb NZ.
Reading Time: 2 minutes

New Zealand’s only known farm with Mycoplasma bovis-infected cattle has been cleared to resume normal farming activities.

The Selwyn dairy farm takes the number of active confirmed properties back down to zero, and the total number of cleared active confirmed properties since 2017 to 282.

The M bovis programme first reached zero active properties in August 2023.

Given the source of infection for this property has not been established, finding more cases in the coming season is expected, OSPRI general manager disease control planning and integration Simon Andrew said.

Six years into the 10-year eradication plan, the eradication effort is moving into a phase that will centre on ongoing surveillance.

Due to the nature of the disease and its ability to remain clinically undetected, Andrew said, several years of data with no new cases of infection need to be collected to provide confidence that M bovis is no longer present on NZ farms.

Going forward, the national surveillance for beef and drystock and bulk tank milk (BTM) testing remain important tools in detecting suspected infected properties.

“Past programme data tell us we are likely to see more BTM detect results  over autumn and spring.”

Andrew urged farmers “to be a mate and update NAIT”.

“The data captured in NAIT plays an important part in helping the M bovis programme trace infection.

“With calf sales picking up and moving day not far away, it’s important to record all movements.”

Meanwhile imported semen has been identified as a way that M bovis may have entered NZ and the M bovis programme partners have implemented a testing project for bovine semen imported into the country before May 2022.

This comes after a farm, in late 2022, confirmed infection with a new strain of M bovis not previously found in NZ.

The Ministry for Primary Industries (MPI) believes semen was the most likely infection pathway as other pathways were ruled out early in the investigation.  

Under a Notice of Direction issued by the MPI under the Biosecurity Act, anyone who has bovine semen that was imported into NZ before May 2022 must supply two straws of semen for testing from all eligible batches they hold, including semen on behalf of clients.

There is one exception – no straws need to be supplied if the semen has been treated with antibiotics in compliance with the Certified Semen Services (CSS) as research has shown the CSS protocol is more effective at preventing M bovis than other antibiotic treatments for semen.

Farmers with eligible imported semen in storage will be required by June 2024 to either approve the submission of straws for testing or opt to destroy unused straws. 

Imports after that date are not included because in May 2022 a new Bovine Germplasm Import Health Standard (IHS) took effect.

The new IHS provides improved risk management.

The MPI assesses the M bovis introduction risk of imported bovine semen as low due to required antibiotic treatments, and with the strengthened IHS in place, the risk is now even lower.

“However, no risk is not the same as zero risk,” prompting the M   bovis eradication programme to apply the same, or similar level of assurance provided by the new IHS to all imported semen in NZ. 

More than $600 million has been spent and 282 infected properties across the country now cleared.

While active confirmed properties are currently at zero, there are 35 properties under active surveillance and two under notice of direction. A total of 2960 claims have been processed totalling $283.1m, with 13 claims in progress.

People are also reading