Screening of bulk tank milk for M. bovis

Find out about the testing of bulk milk from farms as part of the Mycoplasma bovis eradication programme.

Background to screening

The Ministry for Primary Industries (MPI) first announced it would begin national screening of bulk milk in July 2018. The screening was called the 'Spring Surveillance Programme'.

On 19 June 2019, the Mycoplasma bovis Programme, in consultation with industry, announced that screening of bulk tank milk would continue indefinitely. However, a few modifications would be made to the testing regime to improve the ability to identify infected farms and support the eradication of the infection (M. bovis).

National screening will start on 1 July 2019 and be done monthly.

Why testing will continue

The Spring Surveillance Programme proved extremely valuable as it provided assurance that infection was not widespread outside already identified farms. It also identified a small, additional number of infected farms not found through animal movement tracing. And it highlighted the ability of the ELISA test to produce a very low rate of false positive results.

Ongoing screening of bulk tank milk samples nationally may identify infected herds:

  • otherwise undetected due to incomplete and inaccurate movement records
  • faster than the tracing of animal movements, as those movements can only be traced once the source Confirmed Property is found.

How screening will be done

Testing will begin on 1 July 2019.

  • All samples will be taken as part of the normal milk collection process.
  • Your tanker operator will take the samples. You don't have to do anything extra.
  • A single sample will be tested for each month that you supply milk.
  • If the result is ELISA-detect, you'll be contacted as a high priority by MPI with information about next steps.

What's changing about the testing process

  • From 1 July 2019, we will use the ELISA testing method for initial screening of bulk tank milk. This initial ELISA screening indicates which farms could be infected with M. bovis.
  • If an ELISA test result indicates a higher risk of M. bovis infection in a herd, MPI's National Animal Health Laboratory performs follow-up ELISA and PCR testing on these samples.
  • We aim to notify farmers of all ELISA-detect test results within 2 weeks of testing.
  • Farms with an ELISA-detect test result will be placed under a Notice of Direction (a NOD) restricting cattle movements while sampling and testing of the herd is carried out to determine the disease status of the farm.
  • ELISA-negative test results will be regularly reported to farmers once a long-term solution is up and running. In the meantime, it's not practical to manually report the large volumes of negative results.

We recognise that bulk tank milk ELISA-negative results provide some level of assurance and we want to be able to share these results with farmers. We're exploring a sustainable and integrated solution for reporting bulk tank milk ELISA-negative results. There are a few options available. Each of these will take a few months to get up and running. We can't report negative results until an automated solution is available. This is because current manual processes aren't practical and we want to set systems up properly for the long run.

Find out more about the screening – fact sheet [PDF, 260 KB]

Who to contact

If you have questions about the bulk tank milk screening programme:

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