Good biosecurity practices

DairyNZ has worked with farmers to create this helpful WOF. We recommend that you work though this list with your vet.

Biosecurity Warrant of Fitness (WOF) checklist [PDF, 363 KB]

Also have a look at our guide – Avoiding Mycoplasma bovis infection

Managing Mycoplasma Bovis (7.21) – YouTube

Buying cattle tips

When buying stock, always check the source of cattle and their health history. DairyNZ has put together a handy pre-purchase checklist [PDF, 181 KB]

Whenever animals from different farms and groups mix, there’s a risk of spreading infection. The following tips will help reduce this risk.

• Buy and mix from as few sources as possible.
• Ensure any calves you buy were not fed milk (especially discard milk) from other farms.
• Only buy cattle that are lifetime traceable in the National Animal Identification and Tracing (NAIT) system.
• When cattle are moved, record these movements in NAIT when they happen.
• Ask your transporter if they can transport your cattle without them mixing them with other cattle in holding yards or on the truck.
• Keep any cattle that you buy isolated from your other cattle for at least 7 days and monitor for signs of M. bovis.

Deal with a trusted source farm or agent and ask them about:

• stock management and trading practices on the source farm
• the source farm's biosecurity, including boundary fencing and stock quarantine practices
• all stock movement records being up-to-date and recorded in NAIT
• cow and calf health on the farm.

Selling cattle tips

• If you are selling cattle, be prepared to provide the information above to potential purchasers.

Organisers of calf days and other events where cattle are present 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, any risks can be minimised and events like these can still go ahead.

What can exhibitors do?

• Do not transport animals on properties under any suspicion of exposure to M. bovis to shows and events.
• Do not take animals showing clinical signs of any disease to shows, as per normal biosecurity practice.
• Make sure you tag your cattle with a NAIT-compliant tag registered to your property.
• Keep your NAIT (National Animal Identification and Tracing) movements up-to-date and accurate. Record movements to and from the event.

Calf club and event resources

Getting ready for calf club - A3 poster [PDF, 1.3 MB]

Holding a safe calf club – teacher and organiser guidance [PDF, 294 KB]

Minimising the risks at shows and events [PDF, 402 KB]

Information booklet for organisers [PDF, 3.5 MB]

Calf club fact sheet - DairyNZ [PDF, 58 KB]

If sending cattle to grazing, protect them from M. bovis.

• Prevent nose-to-nose contact with cattle from other sources. Discuss this rule requirement with everyone involved in the care and transport of your cattle.
• Ask your transporter to avoid mixing your cattle with other cattle in holding yards or on the truck.
• Make sure all your cattle have National Animal Identification and Tracing (NAIT) tags in their ears and records are up-to-date.
• Promptly record all movements in NAIT.
• If there are cattle from other locations on the grazing property, make sure there’s no opportunity for the different groups to mix.

Grazing resource

Good practices for grazing [PDF, 69 KB]

Bulls that have been in contact with infected cows then moved to another herd are a risk for the spread of infection.

To reduce the risk, observe the following precautions during the mating season.

Bulls arriving on farm – all ages

• Bulls should arrive with a NAIT-compliant tag and all movement history details.
• Ask your vendor or agent about the cattle management and trading practices on the farm of origin. Make sure you let the vendor know your requirements.
• On arrival, hold bulls separately from the main herd for at least 7 days to assess their health status. Complete procedures such as drenching. If you have any concerns about the health of the bulls, contact your vet, before mixing them with the herd.

Bulls leaving the farm

• Ensure they are showing no symptoms of M. bovis.
• If you lease bulls, talk over the options with the owner.
• R2 bulls to slaughter once mating. They must go directly from your farm to the slaughter premises and not via sale yards or any other intermediate stopping point.
• R1 bulls may spread infection between dairy farms if they’re used to service multiple cow herds across seasons. When mating finishes on your farm they should go for fattening then be sent to slaughter.
• If R1 or R2 bulls are being held for further use (such as another mating season) don’t loan or lease them to other farms. Keep them separate from your cow herd and isolated from cattle on other farms.

Beef breed bulls

• Beef-breed bulls from a beef property are a lower risk class of stock and M. bovis test results are unlikely to be available. Ask the vendor or agent if the supplying farm deals in cattle from the dairy industry.
• Bulls that have been on a low number of cattle farms, present the lowest risk of introducing infections including M. bovis.
• The best indicator of the level of M. bovis infection risk is the health status of herds that the bulls have been running with, especially levels of pneumonia and lameness.

The Bovine Germplasm Import Health Standard (IHS) regulates semen imports into New Zealand. It recognises semen is a potential pathway for M. bovis. There are controls in place around the husbandry and health status of donor bulls to reduce the risk of introducing the bacteria.

M. bovis can survive freezing. So antibiotics used in the processing of frozen semen may not be completely effective in killing M. bovis.

To reduce the risk of spreading M. bovis via semen, always ask your semen supplier:

• if they have tested donor bulls for M. bovis
• what assurance can they provide that their semen is free of M. bovis.

The risk of transmission via semen is considered very low – especially after the introduction of the new IHS in May 2022 – but low risk is not the same as no risk. As a precaution, we encourage farmers to use semen imported under the current IHS and:

• if you are planning to use bovine semen that was imported into New Zealand before May 2022, check with your supplier to discuss whether that semen has been treated with the Certified Semen Services Minimum Requirements for Disease Control of Semen Produced for AI (CSS) protocol or has been tested for M. bovis
• ask your semen supplier for advice on what testing the bull and/or semen has been subjected to for assurance that the semen is free of M. bovis.

Certified Semen Services Minimum Requirements for Disease Control of Semen Produced for AI (CSS)  [PDF, 394KB]

Importers of bovine semen are working with the M. bovis Programme to bring all imported semen in stock an equivalent level of protection to the new IHS.

Find out more about the testing programme

M. bovis imported bovine semen testing project

Sharing milk

Sharing milk between farms and feeding it to calves is a high-risk activity for the spread of M. bovis. This means you should try to avoid trading raw milk or colostrum if possible.

Calf milk replacer may be a viable alternative for your farm. Good quality calf milk replacer has a nutritional value comparable to raw milk.

If you do rely on traded raw milk or colostrum:

• minimise the number of farms you source milk or colostrum from
• keep records of when and where you source milk or colostrum from and which groups the milk is fed to
• avoid feeding milk from cows being treated for mastitis or other illnesses
• reduce the risk of M. bovis transmission from fresh milk by pasteurising or acidifying the milk.

Feeding colostrum to young calves

During the first 24 hours of life, a calf can absorb antibodies and essential proteins from colostrum that helps protect it against infectious disease.

Pasteurisation and acidification can destroy some of these antibodies and proteins. So there are benefits to feeding unpasteurised or non-acidified colostrum to calves under 24 hours old. However, you should take extra care to ensure the colostrum is not infected with M. bovis.

Pasteurised or acidified colostrum and milk is suitable for feeding to calves over one day old.

Milk treatment advice

Pasteurisation

Pasteurisation will destroy M. bovis bacteria if done correctly.

The recommended treatment is 60°C for 60 minutes.

Refer to manufacturer specifications for operating the pasteuriser.

Acidification with citric acid

To kill M. bovis by acidifying milk, it needs to be at a pH of 4.5 for at least 8 hours.

• Citric acid is available online and from farm merchant stores.
• Use cool (10°C to 24°C) or cold (less than 10°C) milk to minimise coagulation or clot formation.
• Always add acid to milk, not milk to acid.
• Acidification works best when adding citric acid to fresh milk.
• It's important to accurately measure the weight of citric acid and volume of milk. Use a rate of:
  • 5g citric acid per litre of whole milk
  • 550g per 100 litres of whole milk, and
  • 5kg per 1,000 litres of whole milk.
• Sprinkle the acid on top of the milk while the milk is being agitated.
• At pH 4.5, milk separates, but with gentle mixing goes back into a homogenous solution.
• Do not acidify below pH 4 as this will result in:
  • thickened milk
  • risk of complete coagulation, and
  • calves not drinking the milk.
• Gentle mixing of the milk twice a week is the recommended method. Continuous or vigorous mixing causes coagulation.
• For systems that pipe milk, the milk may coagulate in pipes or tubes with blockage of lines and nipples. This can result in the feeding of whey to calves if the casein coagulates.

Testing pH

• Test the pH of milk half an hour after adding citric acid to the milk.
• Test again just before feeding the milk to calves.
• Use pH test strips. You can buy these online and from farm merchant stores.
• It can be difficult to keep an electronic pH meter clean and calibrated when working with milk. If using one, make sure you clean and calibrate it regularly.

Tracking off-farm movements

NAIT (National Animal and Identification Tracing System) is New Zealand's cattle and deer tracing system. Complying with it is law.

It's critical that you keep up-to-date and accurate NAIT records. This will help us track cattle movements and locate any that could be of interest to the eradication Programme.

It’s also a useful tool for managing your own on-farm biosecurity. It provides a life history of brought-in animals.

Tracking on-farm movements

As well as recording farm-to-farm cattle movements in NAIT, it’s useful to keep good records of on-farm animal movements.

Make a map of your farm and keep detailed records of livestock movements around it. This helps you document the potential for contact between different groups of cattle on the farm. NAIT — information on tracking cattle movements.

Adverse weather

During adverse weather like floods, animals may end up on someone else’s property.

If your animals end up on a farm that is under movement controls, MPI will assess the risk of M. bovis spread. We will decide whether the animals need to remain where they are or if we can release them.

MPI will review these situations on a case-by-case basis.

Talk to us if you’re affected by adverse weather and have concerns about the welfare of your animals.

Rural contractors

Create designated “clean” areas on your farm, 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 you keep stock.

Farm visitors

Make available for any visitors:

• a foot bath with disinfectant and a scrubbing brush to clean boots, and
• clean, hot water and soap for washing hands and any equipment that is taken on and off the farm.

Note, any common agricultural disinfectant will be effective. Be sure to remove all organic matter before disinfecting.

Protect your farm from disease [PDF, 1.2 MB]