Bovine Johne's disease

Johne’s disease is caused by the bacterium Mycobacterium paratuberculosis. Two strains dominate in Australia. One strain is seen as sheep-associated and the other cattle-associated. It is now recognised that both strains can infect multiple species.

Johne’s disease can also affect goats, deer and alpaca.

New management approach

A new framework for the management of Johne’s disease (JD) in cattle commenced nationally from 1 July 2016. Read more about the new JD framework.

Symptoms

  • Fall in milk yield and infertility in milking animals.
  • Diarrhoea. This can be chronic, acute, or intermittent.
  • Weight loss.
  • Emaciation.

There is no treatment for Johne’s disease infected animals.

The disease can have a long period between infection and development of clinical signs. This period tends to be dose related, and may be years in most cases with cattle.

Spread between animals

Johne's bacteria are commonly spread from infected adult cows to the calf through:

  • faeces
  • colostrum
  • milk.

The disease can spread through infected environments. Bacteria can survive for over 12 months in water or sediment however it may survive for less than 3 months in soil and fecal material in dry conditions when exposed to light and heat.

For the purposes of JD management through destocking of all susceptible species a minimum period of 12 months is recommended to decontaminate pasture.

Spread between farms

Disease spread between farms can happen through:

  • Movement of infected animals (this is the most common way of the disease spreading).
  • Movement of infected:
    • vehicles
    • manure
    • water.

Management of Johne's disease

Below is advice for South Australian cattle producers to reduce the risk of Bovine Johne’s disease (BJD) appearing on their farm, and help them keep market access.

  1. Be informed about BJD risk. Speak to your veterinary adviser.
  2. Follow these biosecurity practices to prevent the entry of BJD:
    1. Have a written property biosecurity plan and review it annually. Go to the Farm Biosecurity Action Planner
    2. Make sure all cattle introduced to your property have a national cattle health declaration
    3. Use JDBiosecurity checklist before purchase
    4. Purchase livestock from properties that are involved in an assurance program
  3. Consider joining an assurance scheme like J-BAS or Dairy ManaJD. Those programs can be entry requirements into some interstate markets. For example:
    1. Western Australia requires J-BAS 8 or dairy score 8 plus additional testing
    2. Northern Territory requires a minimum J-BAS 6 or dairy score 7.

J-BAS

The Johne’s Beef Assurance Score (J-BAS) is a risk profiling tool developed for use in the new approach to BJD in beef cattle.

J-BAS is a guide. Producers should always ask further questions about BJD in the herd and on the property, rather than rely on the score alone.

Transitional arrangements for the new J-BAS system finish on 30 June 2017.

SA cattle properties have 3 options until the 30 June 2017

  1. Former MAP properties can transition to J-BAS Level 8. They must maintain their veterinary reviewed biosecurity plan and undertake a check test at least every 3 years. Those planning to access the West Australian market must undertake a higher level of testing and should check with the West Australian government. There must be no infection or suspicion of Johne’s disease in the herd. Producers must investigate and resolve any suspect cases that arise.
  2. Transition into J-BAS Level 7: This requires the producer to have a veterinary reviewed Biosecurity Plan in place the 30 June 2017 and a check test undertaken by the 30 June 2018. There must be no infection or suspicion of Johne’s disease in the herd. Producers must investigate and resolve any suspect cases that arise. Any producers who are not currently in the MAP program but wishing to eventually attain a Level 8 J-BAS score should undertake a sample test not a check test prior to 30 June 2018. This will then count as the first of the 2 sample tests (2 years apart) required to meet the J-BAS Level 8 requirements.
  3. Transition into J-BAS Level 6: This requires the producer to have a biosecurity plan in place the 30 June 2017. This does not need to be endorsed or reviewed by a veterinarian. There must be no infection or suspicion of BJD in the herd. Producers must investigate and resolve any suspect cases that arise.

If none of these above options are undertaken, then the property will be J-BAS Level 0: Unmanaged Risk for bovine Johne’s disease as of the 30 of June 2017.

Dairy ManaJD program

In the SA Dairy Industry, PIRSA manages the Dairy ManaJD program and producers will have a certificate that describes their Dairy Assurance Score.

Over 70% of SA dairy herds are tested and maintain negative herds with a dairy assurance score of 7 or above. These farmers should be aware that introducing cattle of a lower or unknown score will change their current assurance score.

Dairy industry

In South Australia all dairy herds have a Dairy Assurance Score (DAS) based on:

  • number of known infections
  • number of negative tests on the herd
  • other management factors.

Over 90% of SA dairy herds have enrolled in the voluntary program for Dairy farms called 'Dairy ManaJD'.

This program is managed by:

  • local veterinarians
  • farm managers
  • PIRSA.

Each herd gets a Dairy Assurance Score (DAS) based on full herd individual blood test results. More than 70% of SA dairy farms are tested negative properties.

It is compulsory to declare the DAS of dairy cattle offered for sale in South Australia.

Learn more about the Dairy ManaJD program by contacting the BJD program manager.

Beef industry

Historically there is a very low number of JD known infected beef herds in South Australia. However other areas of Australia have historically higher levels. It is also likely that there will be herds in South Australia and interstate that do not know they are infected or have not reported sick animals. SA beef producers can reduce the risk of bringing JD into the herd by good biosecurity practices and being informed about the risks posed by introductions, including sheep.

Important considerations in making choices to purchase are:

  • Determine the level of risk you want to accept – high , medium or low
  • The lowest risk, highest assurance cattle come from herds that have a veterinary approved Biosecurity Plan and have had herd tests completed with negative results.
  • Highest risk cattle are from herds with poor biosecurity practices, with a history of trading in areas of higher JD prevalence, and no herd test done. Individual tests for JD on young cattle are of limited value.
  • Develop your Biosecurity plan (example at Animal Health Australia - Biosecurity Plan) and arrange your purchase choices around this.
  • Do you want to have a tested negative status ( JBAS score 7 or 8) for your herd? Discuss options with your vet or PIRSA officer on the contact details below.
  • Discuss testing options for introduced cattle – this will need to be repeated annually for at least 7 years to gain confidence that cattle are not infected – depending on the sources of purchase.
  • PIRSA continues to provide Certification (an individually numbered Certificate) for JBAS 7 and 8 herds if requested.

Silirum vaccine

Silirum vaccine is a vaccine useful for prevention and management of JD in cattle herds and is  available in SA by Permit from PIRSA. The vaccine is expensive and has advantages and disadvantages in use that producers need to be fully aware of if considering using this vaccine. Contact our Bovine Johne's Program Manager for details.

Contact

Bovine Johne’s Program Manager:

Jeremy Rogers
Phone: (08) 8539 2110
Mobile: 0427 608 133
Email: jeremy.rogers@sa.gov.au

Producer manuals for managing JD

Page Last Reviewed: 20 Mar 2019
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