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.

• Buying calves

  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.

• Buying milk

  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.

  • 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 pasteuriser.
      • 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 stirred gently.
  • 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.

    Download Add to cart

• 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.

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.

• Bulls

  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.

  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. Minimising the number of herds bulls are sourced from will make this process easier.

  Bulls leaving the farm

  If the bulls are leased, then talk over the options with the owner.

  R2 bulls – once mating is finished these bulls should be 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 2020, or spring/summer 2020/2021) 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.

  All farmers must ensure their NAIT records are correct and up to date.

• 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.

  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?

Calf club days and cattle shows

Calf club days and cattle shows can go ahead if biosecurity precautions are put in place. Event organisers should take extra biosecurity steps to avoid the spread of M. bovis. Bringing animals from different herds together does pose a relatively low risk of disease spread, but with good measures in place and precautions, risks can be minimised and events like these can still go ahead.

Biosecurity precautions:

• ensure that calves have their own food and water containers, and their own halter and leads
• calves should be tied up at least two metres away from other calves
• Any sick calves should stay at home

Find out more

Bulk milk testing recommences

The Ministry for Primary Industries have announced that all dairy farms supplying milk will have a bulk sample tested from July 1. Tests will be carried out once a month and will run indefinitely.

Read more about bulk milk testing.

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.

Grazing

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.

Fencing

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.

Feed

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
• abortions
• 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.

M. bovis compensation

If you are a farmer directly affected by M. bovis, we have a 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 dbcat@dairynz.co.nz or dbcat@beeflambnz.com.

To help you with your compensation claim check out the M. bovis Compensation Guide.

Resources

• 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

Sign up for Mycoplasma bovis email updates here

If you are a farmer affected by the M. bovis response, you can find out more about the response on the MPI website.