Mycoplasma bovis (M. bovis) is a bacterial disease, that can lead to serious conditions in cattle and create an animal welfare and productivity issue. In July 2017, the disease was found in cattle in the South Island. Together with the Government and other sector partners we have decided to attempt to eradicate the disease from New Zealand.
Precautions to take during calving
Calves can contract M. bovis through direct contact with infected cattle, or by consuming milk from infected cows. If you’re buying or selling calves or milk, there are some simple steps you can take to reduce the risk of spreading M. bovis and other diseases.
Stock movements are the highest risk for spreading M. bovis.
- Purchase from as few sources as possible.
- Deal directly with the source farm or via an agent.
- Ask about any M. bovis test results available for the farm.
- Ask if the farm has been subject to any M. bovis tracing by MPI.
- Ask about the stock trading practices for the farm.
- Ask if all stock movement records are up to date and recorded in NAIT.
- Ask about cow and calf health on the farm for the past two seasons, and use the pre-purchase checklist.
- Purchase 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 purchased calves isolated from your main group for seven days and monitor them for signs of disease.
- Find a buyer now for your future weaned calves, if possible, and tell buyers about your efforts to reduce risk of M. bovis exposure.
Feeding infected milk is the second highest risk of spreading M. bovis. Feeding milk from your own herd to your own calves carries no extra risk.
- Milk that has the lowest risk of containing M. bovis bacteria comes in these forms: calf milk replacer powder, acidified milk, or pasteurised milk.
- If you’re using milk replacer powder, order now to avoid problems with supply.
- If you’re feeding whole milk from another farm, without purchasing calves from that farm, consider the following:
- Do not feed milk from cows under treatment for mastitis or other illnesses, this milk should be discarded. These cows are more likely to shed M. bovis into their milk than healthy cows.
- Acidification with citric acid to a pH below 5 for at least 8 hours will kill M. bovis but below a pH of 4 the milk will be unpalatable and the calves will refuse to drink it. Our recommended target is 4.5.
- Pasteurisation will kill M. bovis if the machine is working correctly and the proper procedures are followed. There is considerable financial outlay required for a pasteurisation machine.
- Addition of yoghurt to milk is a less reliable way to reduce the pH, as this process takes more time and is temperature dependent to get the culture growing. If the pH doesn’t drop below 5 for at least 8 hours, M. bovis will not be killed.
- M. bovis is not killed by the addition of potassium sorbate preservative.
Advice for acidifying milk with citric acid
- Only acidify milk that you purchased from a source, if you haven't also purchased calves from that source.
- Use cool milk (10-24 degrees) or cold (<10 degrees) to minimise coagulation or clot formation.
- Always add acid to milk, not milk to acid.
- Acidification works best when citric acid is added to fresh milk.
- When using citric acid, the rate is 5.5 grams citric acid per litre of whole milk, or 550 grams per 100 litres of whole milk, or 5.5kg per 1,000 litres of whole milk.
- The acid needs to be sprinkled on top of the milk while it is being agitated.
- Do not acidify below pH 4 as this will result in thickened milk and risks complete coagulation. In addition, calves will not drink milk with a pH of 4 or below.
- Milk at pH 5 and below separates, but with gentle mixing goes back into a homogenous solution.
- Gentle mixing of the milk twice a week is the recommended method. Continuous mixing causes coagulation, as does vigorous mixing.
- Note: for systems that pipe milk, there may be coagulation in the pipes/tubes with blockage of lines and nipples. This may result in the feeding of “whey” to calves if casein coagulates.
- The target pH is 4.5 for a minimum of eight hours. Using the method described here this should be achieved and the M. bovis bacteria will be killed.
- Test the pH of milk half an hour after the addition of citric acid to the milk and again just prior to it being fed to calves. Use pH test strips which can be purchased online and are available in a number of other stores including at farm merchant stores. It can be difficult to keep electronic pH meters clean and calibrated when working with milk.
- Citric Acid is available online and will be available at various other suppliers including at farm merchant stores this spring.
Acidifying milk with citric acid
Correctly acidifying milk kills M. bovis. Use this poster to learn how.
Bobby calves and slinks
Transporting bobby calves to processing poses negligible risk of spreading M. bovis, so bobby calf and slink collection can continue as normal. Ensure that your bobby calf loading facility and slink collection pick up is in a 'green zone' to reduce the risk of exposure to pests, weeds and disease. Read more about green zones and where to have your loading facility. All farms affected by M. bovis - those under regulatory requirements (includes infected properties, those under a Restricted Place Notice and those under a Notice of Direction) - cannot move animals off the property without a permit from MPI.
Requirements specified in the permit
- A truck carrying live animals (including bobbies) must go directly to the processing plant. It may, if permitted, pick up animals from other farms under controls. It cannot, however, pick up calves at unaffected farms on the way. The truck must also be thoroughly cleaned at the plant after discharging the animals – i.e. cannot visit other unaffected farms without having been cleaned.
- As bobby calves are going direct to processing and not onto other farms, there is no residual risk presented by this movement.
- Farmers are encouraged to continue to send bobbies to processing plants.
Spring bulk milk surveillance programme
This spring, all dairy companies are supporting the M. bovis response by testing every dairy farm supplying milk. With the ultimate aim of eradicating M. bovis from New Zealand, this surveillance programme is essential to providing further assurance of previous non-detects. It will help to identify any clusters of disease that have gone undetected so far.
M. bovis can hide in an infected cow, not showing up until weeks or months after the animal has contracted the disease. The spring months are the best time to test for M. bovis because infected animals are more likely to shed the bacteria after a stressful period, such as calving and the start of lactation.
All test samples will be taken as part of the normal milk collection process. The tanker operator will take the samples and farmers will not be required to do anything additional. Testing will begin approximately 4 weeks following the beginning of supply and samples will be collected every two weeks, up to a total of six samples over 12 weeks.
Once the programme is completed, farmers with “not-detected” results will receive an email from their dairy company confirming the disease has not been found in their samples. Those in the North Island will receive their results on or before 1 November and those in the South Island will hear on or before 15 November.
If the result is a positive detect, farmers will be contacted immediately by MPI with information about next steps.
For more information read the spring bulk milk testing FAQs or get in touch with your local dairy company representative.
Protect your farm and animals
You can protect your farm and animals by undertaking some simple biosecurity practices on farm.
Complete the Biosecurity WOF, developed with farmers and vets, work through this guide and develop on on-farm biosecurity plan.
The biggest risk for spread of M. bovis is through direct animal contact, focus on preventing contact with cattle from other herds. If purchasing new stock, read the pre-purchase checklist.
Complete NAIT records
Always complete your NAIT records and make sure if you have had movement over the last month they are correctly recorded. Knowing where your cows have been is crucial to understanding and preventing the spread of disease.
If moving animals for grazing - check the grazing property’s biosecurity health status. All M. bovis infected properties are under Restricted Place Notices under the Biosecurity Act. Ensure that the grazing property has good biosecurity measures in place, such as preventing your stock from having nose to nose contact with stock on the farm or neighbouring properties.
Check your boundary fences are secure
Put in double fencing at least two metres apart to stop nose to nose contact between you and your neighbour’s stock. Permanent is best but in the short term it can be simply putting a reel up if your neighbour’s stock are going to be in the adjacent paddock.
If bringing in supplementary feed - there is no risk of M. bovis infection from bringing in hay or baleage from uninfected farms. If the feed is coming from a farm under a Notice of Direction or a Restricted Place Notice, confirm that it meets any conditions on the Notice.
What is Mycoplasma bovis?
- is a bacterial disease
- is commonly found in cattle all over the world, including in Australia
- it does not infect humans and presents no food safety risk. There is no concern about eating meat, milk and milk products
- it does lead to serious conditions in cattle and therefore constitutes an animal welfare and productivity issue
- it spreads from animal to animal through close contact. Between farms it spreads through the movement of animals that are infected but may not be showing symptoms. It is also potentially spread on contaminated equipment and the feeding of untreated milk to calves. It is not windborne.
- while some of the conditions can be treated, affected cattle will always be carriers of the disease
- the disease does not affect sheep or cause illness in goats although it is thought goats could carry and transmit it.
How does it affect cows?
- untreatable mastitis in dairy and beef cows
- severe pneumonia in up to 30% of infected calves, starting as a hacking cough
- ear infections in calves, the first sign typically being one droopy ear, progressing to ear discharges and in some cases a head tilt
- swollen joints and lameness (severe arthritis/synovitis) in all ages of cattle
- know the signs to look out for, download the 'Signs to look out for' poster. If stock show unusual levels of mastitis, abortions or present with arthritis or pneumonia, contact your vet.
Working to eradicate M. bovis
The decision has been made to continue to focus on eradicating M. bovis from New Zealand. We believe that we have a chance to get rid of it for good by undertaking phased eradication.
Phased eradication will mean continuing to trace all potentially affected cattle, and testing and culling those herds with infected animals in them. This will continue until regular surveillance finds no further evidence of the disease. By phased, we mean that it will take place over a number of years. We expect to do most of the eradication work in 1-2 years. It will be done in cooperation with affected farmers to allow flexibility around timing of culling to offset production losses.
Read more about the decision to eradicate and what it means for you.
Movement control notices
Moving animals for feeding
Surveillance testing = free to move
Cattle that have undergone "surveillance testing" are very low risk for spreading the disease. They can be managed on a grazing block just like any other cattle group – separately, with secure fencing, and prevention of mixing with cattle from other sources. Avoid grazing on adjacent paddocks or use double fencing.
Notice of Direction = restricted movement with permits
NODs are under movement restrictions, but can go to a grazing block under permit. Each ICP manager will help their farmers to do this.
Grazing block NODs
A grazing block that takes cattle from a NOD will become a NOD, but there are options to limit the NOD to parts of a grazing block; and to get back to normal quickly.
Any farm under a NOD will not be financially disadvantaged by it.
For all movements, NAIT must be used correctly.
Please ensure all your stock have NAIT ear tags. This is your responsibility. If you are a grazier with feed available and would like to assist, please contact MPI on 0800 00 83 33 or email MBovis2017_Liaison@mpi.govt.nz.
Farmers under NOD who need to graze
Farmers under NODs should contact their ICP manager to arrange the permit. The process is:
- Farmer locates grazing that will accept NOD cattle and contacts ICP manager.
- MPI visits the location and assesses fence security and the suitability of the property/paddock(s) to contain possible disease.
- The permit may be granted within a couple of days if all information is provided quickly and correctly and there are no problems.
- The cattle will be moved to the grazing block by permitted transporters. The NOD goes with the animals, and will apply to all or part of the grazing block depending on the size and the location of the cattle.
- The cattle will be unloaded using portable yards if there are multiple herds at the property; MPI will also compensate for double fencing and any equipment needed to manage the NOD animals as a separate group.
Farmers should contact their ICP manager or Rural Support Trust lead to assist them with getting their cows to feed.
What is a Restricted Place Notice?
- Restricted Place Notices (RPNs) are issued to properties that are believed to have, or are suspected of having Mycoplasma bovis
- The RPN prohibits all unauthorised movements of stock and other risk goods ontoand off the farm to minimise the likelihood of the disease spreading from the property.
- Any movement of cattle requires a permit from MPI.
- Transport vehicles are required to follow a cleaning and disinfection process when they leave a Restricted Place.
- AsureQuality staff are ensuring cleaning and disinfecting and permit protocols are being met.
- All incidents of non-compliance are followed up by MPI.
What is a Notice of Direction?
- Notice of directions (NoDs) are issued to farms when an inspector or authorised person considers that movement of stock and other risk goods from a property poses a risk of spreading Mycoplasma bovis. For example, this can be when animals from infected properties have been moved to that property but testing has not yet taken place or results of testing are pending.
- The NoD is aimed at preventing further spread and does not restrict movement of stock or goods on to the farm.
- Cattle can only move off the farm with a permit.
- Other steps such as cleaning and disinfection of vehicles may be required.
- All incidents of non-compliance are followed up by MPI.
- Looking to buy more cattle? Read the M. bovis pre-purchase checklist
- Mycoplasma bovis advice on using imported or local semen
- Managing service bulls
- Minimising the risks from Mycoplasma bovis at cattle shows and events
- M. bovis - calf club day advice