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Read about the symptoms and causes of Bovine Johnes disease

Bovine Johne's Disease

Bovine Johne's Disease (BJD) is a chronic, incurable disease of adult cattle caused by the bacteria Mycobacterium paratuberculosis. Symptoms include diarrhoea, reduced milk production, weight loss and eventually death. The disease is mainly spread through ingestion of contaminated feces. Infection is usually acquired in calfhood but generally no clinical signs are seen until animals are at least four years old. It is difficult to reliably detect infection in live animals, particularly in the early stages of the disease.

Preventing exposure of susceptible young calves, introducing only low-risk cattle and targeted testing and culling of animals to reduce shedding of Mycobacterium paratuberculosis into the environment are the keys to controlling spread in a herd.

The Australian dairy industry is committed to controlling the spread and limiting the impact of BJD. Our vision is to increase awareness and understanding of this disease and to have all farmers implement measures to control the risks posed by BJD.

Managing the risk in Australian dairy herds

Understanding more about BJD and how to manage the risk is an first important step in dealing with the disease. Whether you want to be part of a formal control program or to just minimise the risks in your own herd, there are many things that can be done.

More information

These publications contain important information and guidelines for best practice:


Dairy farm guidelines for BJD control: Best practice recommendations for managing bovine Johne'™s disease in Australian dairy herds (PDF, 1.1MB)

A booklet for dairy farmers containing best practice recommendations for managing BJD in Australia.

Dairy BJD Technotes: Best practice recommendations for managing bovine Johne'™s disease in Australian dairy herds (PDF, 4.1MB)

A technical booklet for veterinarians and herd advisers discussing best practice recommendations for managing BJD in Australia.

New approach to Bovine Johnes Disease (PDF, 144KB)

Dairy strategies to manage BJD.

BJD control programs for Australian dairy herds

The control of BJD in Australia is implemented according to a strategic plan. The dairy industry is promoting the use of the National Dairy BJD Assurance Score and adoption of hygienic calf rearing practices through the 3-Step Calf Plan and/or the Johne'™s Disease Calf Accreditation Program (JDCAP).

 

1. The 3-Step Calf Plan

Limiting calf contact with adult cattle and sources of manure minimises the risk of BJD and many other diseases including calf scours. This is the basis of the 3-Step Calf Plan. Implementing the 3-Step Calf Plan is an excellent way to reduce the risk of BJD in a herd and improve the overall health of calves.

More information

3 Steps to minimise BJD risk in your herd (PDF, 1167KB)

All dairy companies have included the 3-Step Calf Plan in their on-farm quality assurance programs to support BJD control and good calf health. This brochure explains in more detail the three steps to minimise BJD risk in your herd and other best practice recommendations. 

2. Johne's Disease Calf Accreditation Program (JDCAP)

JDCAP is an audited calf rearing program designed to minimise the risk of spreading BJD in Victorian dairy herds, should it be present, from adult cattle to calves. Calves raised under an accredited rearing system have a lower risk of contracting BJD than non-accredited calves. More information is available from the Agriculture Victoria website.

National Dairy BJD Assurance Score (Dairy Score)

The Dairy Score allows dairy farmers to compare the risk of BJD in groups of cattle when they are buying or selling stock. A herd's Dairy Score takes into account the location of the herd and the BJD history of a property, including management practices, laboratory test results, enrolment in BJD assurance or control programs. Cattle with a higher Dairy Score are considered to be a lower risk of having BJD.

What's the score with BJD? (PDF, 2364KB)
This brochure provides an introduction to Dairy Score, and includes a reckoner which can be used  for individual animals.

Pathways to progress with Bovine Johne's Disease (PDF, 1274KB)
A technical booklet for veterinarians and herd advisers describing the National Dairy BJD Assurance Score with answers to frequently asked questions.

Dairy BJD Assurance Score Declaration Form (PDF, 289KB)
This form is used to to make an official declaration of your herd BJD Assurance Score.

External links

The following information may prove useful to understanding more about BJD and how it is being managed in Australia and overseas.

Australian BJD information:

International Links on BJD:

Extensive Bovine Johne's Disease information site run by the University of Wisconsin
International Association for Paratuberculosis

In This Section

  • FAQ Calves

    FAQ Calves

    Guidance for veterinary practitioners, government animal health staff and dairy herd advisers on the Dairy Score.

    Q: What are calf credits?

    A: These are bonus points available to cattle when as calves they were reared in accordance with the requirements of the Victorian JDCAP (+3 credits) or the 3 Step Plan (+1 credit). Calf credits are added onto the herd'™s lowest base Score that the herd had in the animals first 12 months of life. This then becomes the Score for those individual cattle reared under these programs. For example, calves reared under the 3 Step Plan (+1 point) in a base Score 3 herd are eligible for Score 4 (3+1).

    Q: How does the 3 Step Calf Plan affect the Dairy Score of Non-Assessed herds?

    A: Non-Assessed herds have no testing history for BJD, however if the 3 Step Calf Plan was implemented and documented prior to July 1 2008 in herds within NSW, VIC, SA or TAS, then herd base Scores in these regions is Dairy Score 3. If calf hygiene controls were not introduced before July 1 2008, the herd base Score is 0.

    Q: What is the maximum Score attainable for individual cattle reared as calves under either JDCAP or the 3-Step Plan?

    A: Score 7 is the maximum individual animal Score for calves reared under either JDCAP (+3 points) or the 3 Step Plan (+1 point) where calf credits are added to the base Score for the herd. For example, calves reared under JDCAP in a herd that is in the Victorian Test and Control Program, which has attained RD2 (Score 6), can only claim a maximum of Score 7 not Score 9.

    Q: Does my Non-Assessed Herd Dairy Score improve to Dairy Score 4 when I have been rearing calves hygienically for many years?

    A: Yes. Hygienic rearing of calves adds to BJD assurance and is reflected in the Dairy Score. If measures have been in place for 4 years, the herd base Score for Non-Assessed herds with no history or occurrence of BJD is Dairy Score 4.

    Q: Do calves reared under JDCAP or the 3-Step Plan keep their Score for life?

    A: Yes. Calves reared under JDCAP can attain a maximum of Score 7 which is maintained for life eg. base Score 4 + 3 JDCAP credit points. The animals must have been reared under the JDCAP program for 12 months ”although this may not necessarily have been continuous on the same property.

    Q: What is the definition of an adult animal in the context of the Dairy Score?

    A: Any animal over 12 months of age.

    Q: Does a previously Non-Assessed herd that undertakes a Check Test, with negative results, have to implement the 3-Step Plan to maintain Score 7?

    A: No, however it is strongly recommended, especially if cattle are being introduced into the herd for any reason. Note that to maintain Score 7, the herd must be retested every 2 years by Check Testing 50 animals.

    Q: What is the base Score for a herd that has been implementing JDCAP for a number of years?

    A: After 4 years of an approved calf rearing program the base herd score is increased by one point. In herds where JDCAP has been implemented for 4 years or more, and this can be substantiated with documentation, the base Score of the herd is Score 4.In herds where JDCAP has been in place for less than 4 years, the base Score of the herd is Score 3, until 4 years of JDCAP is achieved.

    Q: At what age do calves reared under JDCAP or the 3-Step Plan become eligible to claim calf credits?

    A: Calves less than 12 months old are not eligible to claim the relevant credit points.

    Q: Is there a requirement to have the 3 Step Calf Plan audited?

    A: No, formal auditing of the 3 Step Calf Plan is not required, however if points are included for the 3 Step Calf Plan when calculating the Dairy Score for animals, auditable records must be maintained showing evidence of the Plan. Dairy companies have included the 3 Step Calf Plan as a part of their on-farm QA programs.

    What assurance have I got that animals who'€™s Dairy Score includes credit points for calf rearing have, in fact, been reared this way?

    The Dairy Score has been introduced as a self-assessed tool to provide information on the risk of animals having BJD. Declaration of an animals Dairy Score can be entered in Section 9 of the National Vendor Declaration (NVD). If calf rearing credit points are included in the determination of an animal'™s Dairy Score, the vendor must able to provide adequate evidence to accurately support this Dairy Score declaration. A false declaration may lead to prosecution.

  • FAQ Declaring the score

    FAQ Declaring the score

    Guidance for veterinary practitioners, government animal health staff and dairy herd advisers on the Dairy Score.

    Q: Do I need to register the Dairy Score of animals in my herd with a third party?

    A: No, registration with a third party is not required. However, herd records should be available when the Dairy Score of animals is declared in Section 9 of the National Vendor Declaration (NVD) when selling dairy cattle. A BJD Declaration Form may be required in other circumstances where an NVD is not required, such as when displaying animals at Shows, and must be able to be supported with herd record evidence if required.

    Q: How should buyers and sellers of replacement cattle declare the Score?

    A: The Score should be written in Section 9 on the National Vendor Declaration (NVD) as: œDairy Score XX. It is a mandatory requirement of the South Australian Dairy ManaJD program to declare the Score of all cattle offered for sale.

    Q: When required, how should farmers formally declare the Score?

    A: From time to time a farmer may need to declare the Score in more detail than the National Vendor Declaration allows (eg for entry to a show). A standard declaration form is available for download from Animal Health Australia (www.animalhealthaustralia.com.au); the dairy industry BJD web site (www.dairy.com.au/bjd); or, by collection from local State government animal health offices.

    Q: Are farmers issued with a Dairy Score certificate?

    A: No certificates are issued for the Dairy Score; except for:

    Herds that have enrolled in the South Australian Dairy ManaJD program; or
    Herds that are participating in the Australian Johne's Disease Market Assurance Program for Cattle (CattleMAP) will have certificates for their respective MN status

  • FAQ Herd introductions

    FAQ Herd introductions

    Guidance for veterinary practitioners, government animal health staff and dairy herd advisers on the Dairy Score.

    Q: What happens to the base Score of the herd when adult cattle with a lower Score are introduced?

    A: The base Score of the herd is lowered to the lowest Score adult animal. Because individual adult animals keep their Score for life, there is no effect on the Scores of either the introduced adult cattle or the adult cattle already in the herd.

    Q: What happens to the base Score of a herd when adult cattle with a higher Score are introduced?

    A: No change to the base Score of the herd.

    Q: How do leased and introduced bulls affect the base Score of a herd?

    A: The situation with respect to bull introductions is considered different to that of introduced female cattle and there is no change in the base Score of a herd. This is due to the generally lower risk conditions associated with their introduction.

    Farmers need to adopt sound risk management when bulls are to be introduced to ensure there is no increased risk of BJD. Factors which reduce the risk from the introduction of bulls are:

    Bulls are kept separate from calving cows and from animals less than 12 months of age
    Beef bulls have lower risk as BJD prevalence is much lower in beef cattle
    Young bulls (typically 2-4 years), even if infected, are unlikely to excrete organisms
    Bulls, if leased, spend only short time on the farm
    Small numbers of bulls introduced
    Bulls are introduced from CattleMAP herds

  • FAQ Individual and herd base score

    FAQ Individual and herd base score

    Guidance for veterinary practitioners, government animal health staff and dairy herd advisers on the Dairy Score.

    Q: Do individual adult cattle have their own Score?

    A: Yes. An individual adult animals Score is derived from the herd'™s base Score (which is determined by the lowest Score animal on its property of origin) when the individual was less than 12 months of age; plus any applicable calf credits.

    The underpinning principle is that cattle 12 months and older keep their Score for life because the risk of adult cattle becoming infected is low. However, in some situations their Score may change as further information on their assurance becomes available. For example, in a previously Non-Assessed herd, the Score for individual cattle may change if the herd is tested; because testing reveals additional information on the risk of BJD in the herd.

    For example, where a NA herd has a Check Test with negative results, the Score for cattle within the herd is increased from Score 0 to Score 7.

    During the transition period, some herds that test in the Control and Residual zones could theoretically revert to a lower Score (from Score 3 to Score 2) if there is subsequently found to be a high prevalence of infection in the herd.

    Thus, in the literal sense, the Score for individual cattle (from a NA herd) is not strictly for life but until further assurance is demonstrated.

    Q: What is meant by the ˜base Score™ for a herd?

    A: The base Score of the herd is the score of the lowest Score animal (ie. highest risk) in the herd.

    Q: What is the starting base Score of a previously Non-Assessed herd that has blood test positive cattle at its first whole herd test?

    A: In this situation, the presence of blood test positive cattle indicates that the herd may be infected and would be classed as Suspect (Score 1) until further testing is undertaken. A follow up confirmatory test, using either faecal culture or slaughter and histopathological examination, should be performed to clarify the true disease status of the herd. If Mycobacterium paratuberculosis is cultured or identified at post-mortem from one or more animals, the herd may then be classified as Infected. The herd would then have a base Score of 1 until further approved control measures that reduce the risk are implemented.

    How does a herd maintain base Score 7?

    Check Testing needs to be repeated within 24 months to maintain the base Score for a herd at Score 7.

    A Check Test is a test of 50 animals in the herd, biased to increase the probability of detecting infection. Animals should be selected so as to increase the herd level sensitivity of the Check Test by maximising the probability of finding an infected animal. This is achieved by sampling those animals most likely to be infected and most likely to react to the test. This includes: animals in poor condition, older animals, and introduced animals.

  • FAQ Information sources

    FAQ Information sources

    Guidance for veterinary practitioners, government animal health staff and dairy herd advisers on the Dairy Score.

    Q: What if I cant work out the Score?

    A: In situations where determining the Score for a group of cattle is not clear, farmers are advised to contact an approved veterinarian or local State government animal health offices.

    Q: Where do I find information for interstate movement requirements on Johne'™s?

    A: Local State government animal health offices or the State BJD coordinators should be contacted in relation to the BJD requirements for interstate movement, and any other animal health requirements.

    Q: What are the legal requirements with respect to the sale of land and Bovine Johne's disease?

    A: Please contact your local State government animal health office for advice.

    Q: What happens to a dairy farm that goes out of dairying and into beef production?

    A: The Dairy Score does not apply to beef cattle.

    A non assessed herd on a dairy farm that subsequently becomes a beef farm is initially ineligible for the Beef Only scheme; unless the dairy herd was enrolled in the CattleMAP.

    Please contact your local State government animal health office for further advice regarding Johne's disease in beef cattle and the declaration requirements for Beef Only.

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DairyBase is a web-based tool that enables dairy farmers to measure and compare their farm business performance over time.

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