M. bovis update (30 September 2020)
Managing service bulls
The highest risk for the spread of M. bovis is the movement of infected animals from one herd to another. Bulls who have been in contact with infected cows, and then moved to another herd are a risk for the spread of infection.
Testing for Mycoplasma bovis in bulls
M. bovis is not an easy disease to test for on an individual animal basis, especially in animals not showing clinical signs. The tests available are designed to either work at a herd level, to show animals are having immune responses to circulating infection in the herd, or on animals actively shedding the bacteria. Animals only shed M. bovis intermittently, and immune responses to infection vary. Therefore, negative results on a single bull can’t be interpreted to mean that that animal is not infected, and a positive result on the herd test does not mean that the bull has M. bovis either. The best indicator of whether an animal may be infected is the health status of the herd the animal comes from.
Interpreting the test results
Animals from dairy herds that have been tested and where infection is not detected can be considered low risk for spread of infection. Herds with test results that indicate evidence of M. bovis infection will receive directions from MPI on the management and movement of animals, and owners of bulls that have been there will be contacted. Ensuring your animals' NAIT movements are recorded will assist in this situation.
It is essential that the bulls are properly identified and NAIT records are completed promptly for all movements.
Recommendations for management of bulls:
Bulls arriving on farm – all ages
Bulls should arrive properly identified and accompanied by details of their movement history and health status of the herd they have been in. Make sure you let the vendor or agent know that you will be expecting to be provided with these details. Minimising the number of herds bulls are sourced from will make this process easier.
On arrival the bulls should be held separately from the main herd for at least 7 days to enable an assessment to be made of their health status, and for any procedures such as drenching to be completed. If you have any concerns about the health of the bulls, contact your veterinarian before you mix the bulls with the herd.
Bulls leaving the farm
If the bulls are leased, then talk over the options with the owner.
R2 bulls – once mating is finished it is recommended that these bulls are sent directly to slaughter. It is important that they go from the farm to the slaughter premises directly and not via saleyards or some other intermediate stopping point. If they are being held for further use (mating in autumn 2021, or spring/summer 2021/2022) then the recommendations for R1 bulls should be followed.
R1 bulls – these bulls may be a risk for the spread of infection. The best indicator of the level of risk from these bulls is the health status of the herd the bulls have been running with - pay particular attention to the herd’s levels of mastitis and lameness. The bulls with the lowest risk are those that have been on the fewest number of other properties.
All farmers must ensure their NAIT records are correct and up to date. If you need assistance with your NAIT account contact OSPRI.
Using imported or local semen
The Import Health Standard (IHS) that regulates the importation of semen into New Zealand recognises that semen is a potential pathway for M. bovis. The IHS has controls in place around the husbandry and health status of donor bulls to reduce the risk of introducing disease.
Tests for the disease in semen exist but are not particularly reliable. M. bovis can survive freezing, and antibiotics routinely used in the processing of frozen semen may not be completely effective in killing mycoplasmas. However, the risk of spreading M. bovis via semen is low.
What can farmers do?
Ask your semen supplier:
- What kind of assurance can your semen supplier give that insemination of your herd will not lead to M. bovis on your farm?
- Have the donor bulls been tested for M. bovis?
Many farmers will now be buying, selling, and/or moving weaned calves to grazing. There are steps you can take to help protect your animals from M. bovis.
Sending weaned calves to grazing
Stock movements are the highest risk for spreading M. bovis.
Protect your calves from exposure to M. bovis by preventing nose to nose contact with cattle from other sources. Discuss your expectations with everyone who is involved in the transport and care of your calves once they leave the home farm.
- Transport - Ask your transporter to avoid mixing your calves with other cattle in holding yards or on the truck.
- NAIT - Make sure all your calves have their NAIT tags in their ears and promptly record all movements.
- If your calves are being grazed on a property with cattle from other sources, measures must be taken to completely prevent your calves from coming into contact with them.
- Visit the Biosecurity for Grazing Properties page to learn about the risks and solutions for specific areas on the grazing block.
- Graziers can use this Communication Plan to help them get organised and protect their property.
Buying and selling weaned calves
Stock movements are the highest risk for spreading M. bovis.
- Know the source
- Purchase from as few sources as possible.
- Deal directly with the source farm or via an agent.
- Ask if the farm is subject to any Mbovis tracing by MPI.
- Ask about the stock trading practices for the farm.
- Ask about the source of all milk fed to calves on 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.
- If you are selling, ensure your calves are tagged and registered, and be prepared to provide the information above to people buying your calves.
- Know the source
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.
Contractors and machinery on farm
The risk of spreading M. bovis bacteria between farms on machinery is low. However, it is good biosecurity practice to have a “clean on, clean off” policy for both machinery and people, which will protect your farm business from weeds, pests, and diseases. You should expect machinery to arrive clean to your property, and expect the machinery to be cleaned before it leaves your property for the next job. Disinfection should be used after cleaning on equipment and boots/gear that have been in contact with stock and/or effluent. Check out the cleaning and disinfection poster for more information.
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.
Bulk milk testing
All dairy farms supplying milk will have a bulk sample tested for M. bovis every month. This is part of the ongoing surveillance programme as we work to eradicate M. bovis from New Zealand.
Working to eradicate M. bovis
We believe that we have a chance to get rid of M. bovis 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.
M. bovis compensation
If you are a farmer directly affected by M. bovis, we have a team that can help you with compensation.
The DairyNZ and Beef + Lamb NZ Compensation Assistance Team can help you with:
- understanding whether you are eligible for compensation
- clarify what losses you can claim for
- working through the compensation claim forms with you
- supporting you through the compensation claim process
This is a free service that is supported by MPI, run independently by DairyNZ and Beef + Lamb NZ.
Call us on 0800 322 281 and we will put you in touch with a compensation assistant to help step you through the process and ensure you have the answers you need. Alternatively you can email the team at firstname.lastname@example.org or email@example.com.
To help you with your compensation claim check out the M. bovis Compensation Guide.
- Looking to buy more cattle? Read the M. bovis pre-purchase checklist
- Mycoplasma bovis advice on using imported or local semen
- Minimising the risks from Mycoplasma bovis at cattle shows and events
- Rural Support Trust can help you
If you are a farmer affected by the M. bovis response, you can find out more about the response on the M. bovis affected farmers website.