Farmers play the most important part in the success of eradicating disease.
To reduce the risk of disease spread (for many diseases, not just M. bovis), there are some practices that farmers must be doing to protect their own and other farmers’ herds.
Take a look at the following topics to see how you can help reduce the risk of spread.
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.
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
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.
When buying stock, always check the source of cattle and their health history.
DairyNZ has put together a handy pre-purchase checklist.
Whenever animals from different farms and groups mix there’s a risk of spreading infection. The following tips will help reduce this risk.
If sending cattle to grazing, protect them from M. bovis by:
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.
The 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:
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:
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.
Pasteurisation
Pasteurisation will destroy M. bovis bacteria if done correctly.
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.
- 5g citric acid per litre of whole milk
- 550g per 100 litres of whole milk, and
- 5kg per 1000 litres of whole milk.
- thickened milk
- risk of complete coagulation, and
- calves not drinking the milk.
Testing pH
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.
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.
Make available for any visitors:
Note: any common agricultural disinfectant will be effective. Be sure to remove all organic matter before disinfecting.
DairyNZ has worked with farmers to create this helpful Biosecurity Warrant of Fitness (WOF) checklist.
We recommend that you work though the list with your vet.
Also have a look at our guide - Avoiding Mycoplasma bovis infection.
Watch: Managing the risk of M. bovis