Advice about Mycoplasma bovis for all farmers

What you need to know to help stop the spread of Mycoplasma bovis.

Resource library

We have a range of resources to help farmers, industry, and the general public on issues with Mycoplasma bovis. Our resource library has documents, guidance, and fact sheets you can download.

Look out for signs and report the disease

Look out for signs of Mycoplasma bovis. Report any signs to:

  • your vet
  • the Ministry for Primary Industries (MPI) on 0800 80 99 66

Signs in cows include:

  • unusual mastitis in cows that doesn't respond to treatment
  • arthritis 
  • late-term abortion
  • high numbers of calf deaths.

Signs include in calves:

  • severe pneumonia, starting as a hacking cough
  • arthritis 
  • ear infections. The first sign typically being one droopy ear, progressing to ear discharges, and in some cases a head tilt
  • conjunctivitis.

Not all infected animals get sick. Sometimes the disease is dormant and only appears when animals are under stress – for example, when calving, being transported, or in adverse weather. Those animals can spread the disease to other cattle through close contact.

Poster of Mycoplasma bovis – what to look out for [PDF, 636 KB]

Mycoplasma bovis mainly affects cattle and has little effect on other production animals. It does not affect horses and other pets.

Practice good on-farm biosecurity

The disease spreads in 2 ways:

  • by animal-to-animal contact
  • by feeding infected milk to calves.

You can help protect your farm and prevent the spread of the disease by doing on-farm biosecurity checks.

Biosecurity measures extend to any farm service providers such as contractors and trucking companies.

Keep NAIT and animal movement records up to date

NAIT (National Animal Identification and Tracing) is New Zealand's cattle and deer tracing system and complying with it is law. It's critical that you maintain up-to-date and accurate NAIT and other animal movement records. Accurate record keeping helps us track animal movements and locate any that could be affected. It is also a useful tool for managing your own on-farm biosecurity by providing you with a complete history of brought-in animals.

Trucks taking calves from affected farms won't go to unaffected farms 

Farms that are infected, or being tested, are under regulatory controls – they can't move animals off the property without a permit from MPI.

The permit sets out requirements that the farmer and transporter must meet. In particular, a truck carrying live animals (including bobby calves):

  • must go directly to the processing plant
  • may, if permitted, pick up animals from other farms under controls, but not from unaffected farms
  • must be thoroughly cleaned at the plant after unloading the animals
  • can't visit other unaffected farms unless it has been cleaned.

What farmers can do

Create designated areas on your farm that are 'clean' areas – where bobby calf and slink pick-ups and other public movements can take place. For example, use the tanker track or house driveway. Make sure these areas are well separated from areas of the farm where stock is kept.

Find out more

Protect stock when grazing off the home farm

Thousands of New Zealand dairy cattle are wintered or grazed off their home farms. There are many ways graziers can protect the health of the stock they manage.

DairyNZ and Beef + Lamb New Zealand have information sheets you can download.

Advice for managing service bulls and semen

The highest risk for the spread of infection is the movement of infected animals from one herd to another. Bulls who have been in contact with infected cows then moved to another herd, are a risk for the spread of infection. There are precautions you can take this mating season.

Buying stock

When buying stock, check the source of the cattle and their health history.

Use this pre-purchase checklist to help you – DairyNZ

Weaned calves

If you're buying, selling, or moving weaned calves to grazing there are steps you can take to help protect your animals from M. bovis. Stock movements are the highest risk for spreading the disease. 

Sending weaned calves to grazing

Protect your calves from exposure to M. bovis by preventing nose-to-nose contact with cattle from other sources. Discuss this with everyone who'll be involved in the transport and care of your calves once they leave the home farm.

  • Ask your transporter to avoid mixing your calves with other cattle in holding yards or on the truck.
  • Make sure all your calves have NAIT tags in their ears and promptly record all movements.
  • If your calves are being grazed on a property with cattle from other sources, make sure they are completely prevented from coming into contact with them.

Visit the DairyNZ website to learn about ways to protect stock against the risks in specific areas on a grazing block.

Buying and selling weaned calves


Buy calves from as few sources as possible.

Deal directly with the farmer selling the calves or an agent. Make sure you ask them:

  • about any M. bovis test results for the farm
  • if the farm is subject to any M. bovis tracing by MPI
  • about the farm's stock trading practices
  • about the source of all milk fed to calves on the farm
  • if all stock movement records are up-to-date and recorded in NAIT
  • about cow and calf health on the farm for the past 2 seasons – use the DairyNZ pre-purchase checklist

Make sure you:

  • buy only calves with NAIT tags and promptly record all movements
  • ask your transporter to avoid mixing calves with other cattle in holding yards or on the truck
  • keep bought calves isolated from your main group for 7 days and monitor them for signs of disease.


If you are selling, be prepared to provide the information above to people buying your calves.

RFID numbers

Help us find unregistered tag numbers

29 August 2018: Through our extensive tracing work, Biosecurity New Zealand has identified 660 unregistered RFID (radio frequency identification) ear-tag numbers believed to have originated from an infected property.

We are encouraging farmers and stock traders to check the numbers in the 660 unregistered RFIDs file and let us know if you find any – phone 0800 00 83 33.

Check the list

Below is a list of RFID (radio frequency identification) ear-tag numbers from farms under Restricted Place Notices. Any farm that is under a Restricted Place notice is unable to move or trade any stock.

These RFID numbers shouldn't appear on:

  • any animals being purchased
  • a property that is not a Restricted Place.

If you find any of these numbers outside of a Restricted Place, phone us immediately on 0800 00 83 33.

We'll be updating the list regularly but we can't guarantee that it is always up to date because of the fast-changing nature of the Mycoplasma bovis response. Use of this information shouldn't substitute best practice. Make sure you continue to check the animal's original source and health history.

This RFID list does not yet include all properties. We'll be adding to it over time.

Calf days, cattle shows, and events

For spring 2019, we recommend against schools and clubs holding calf days. Bringing animals from different herds together does pose a risk of disease spread. While the risk is relatively low, we are in a critical phase for tracking down and eradicating Mycoplasma bovis and unnecessary mixing of animals at events like calf days should be avoided.

If schools and clubs do go ahead with events, ensure you have consulted with your communities and taken all sensible precautions. Our fact sheet has some simple precautions you can take to minimise the risks.

Adverse weather events

Most farmers are used to dealing with severe weather events and should have their usual contingency plans in place. Flooding is common in many parts of New Zealand. Mycoplasma bovis (M. bovis) is not a waterborne disease so there is no risk of spread from flood waters. All confirmed cases of M. bovis infection in New Zealand were spread through prolonged and repeated contact between animals, or feeding of infected milk to calves.

Farms not under movement controls for M. bovis should follow normal contingency plans during adverse weather events.

Get more advice about animals affected by floods [PDF, 196 KB]

Farms under restrictions for M. bovis

In flood-prone areas, urgent animal evacuations may be needed for farms under a Notice of Direction or a Restricted Place Notice for M. bovis. Farmers on properties with a known flooding risk should work with their case manager to arrange pre-approved movement permits for such events.

MPI relies on farmers to inform their case managers if they are in flood-prone zones, or at risk from other severe weather hazards. Analysis of geo-data for all properties under movement controls is also being planned. These farmers and their case managers can go over contingency plans and identify if urgent movement permits could be needed before or during floods. With this planning in place, MPI’s permitting team can help support animal welfare and farmer safety with quick issuing of permits if there is an adverse event. Farmers under legal controls from MPI should not knowingly allow any animals to come onto their farm, as the risk of spreading the disease is high.

Neighbours of farms under restrictions for M. bovis

MPI works with the farmers placed under a Restricted Place Notice for M. bovis to let their neighbours know about the infection. So far we’ve had no evidence of the disease spread through over-the-fence contact between animals. But the notification lets the neighbours ensure that they have strong and wide fence lines in place. During an adverse weather event, if animals from neighbouring farms accidentally end up on the farm placed under legal controls, MPI will have to assess the risk of M. bovis spread to decide whether the animals have to remain there or not.

All other farms

Occasionally, during adverse weather events like floods, animals from farms not under legal restrictions from MPI may end up on someone else’s property. If your animals accidentally end up on a farm placed under a legal restriction (either a Notice of Direction or a Restricted Place Notice), MPI will assess the risk of infection for M. bovis before deciding if these animals will need to remain there or if they can be released. MPI will review these situations as they arise on a case-by-case basis. If MPI decides that these animals have been exposed to M. bovis and have to be culled, you may be eligible to submit a compensation claim for your losses under the Biosecurity Act 1993.

Support for farmers

We understand this disease will be stressful for farmers who are affected and farming communities.

If you are a farmer and need support, help is available through your industry group representative, individual response case manager, or the Rural Support Trust.

Industry representatives

We're calling on rural communities to support each other, especially affected farmers and those that appear to be finding it hard. If you have any concerns about someone you know, contact the Rural Support Trust or other community support services.

Looking after yourself – fact sheet [PDF, 1.2 MB]

Find out more

If you have questions about Mycoplasma bovis:

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