History of OJD in Australia

National Ovine Johne’s Disease Control and Evaluation Program (NOJDP) 1998-2004

The six-year NOJDP commenced in 1998 and concluded in June 2004. It was an initiative of the livestock industries and state and Australian governments, and was managed at the national level by Animal Health Australia. The states were responsible for managing and implementing operational aspects of the program.

The NOJDP resulted in the accumulation of a world leading body of knowledge relating to the diagnosis, management and control of Ovine Johne’s disease. At the conclusion of the program the national sheep industry had arrived at a better understanding of the extent of the disease within Australia and also the challenges facing producers and governments who implement control and management programs. The disease was more widespread than had been initially anticipated and a traditional control program based on regulation was considered unnecessarily restrictive on trade.

Research projects over the six years of the NOJDP included:

• testing current on-farm eradication strategies
• evaluating vaccination for on-farm control
• evaluating factors important for on-farm control strategies
• investigating spread and development of ovine Johne’s disease within a flock
• development of techniques to assess the level of contamination in paddocks and how infective they are
• abattoir surveillance techniques
• evaluation of the risks associated with the use of semen from infected flocks
• assessing the level of production losses attributable to ovine Johne’s disease, and
• refining existing tests and evaluating new tests.

During the NOJDP, surveillance was used as a method of establishing the true ovine Johne’s disease status of regions and identifying infected flocks. While determining the extent of the disease through surveillance and carrying out the R&D program, states also attempted to minimise the spread of the disease. The strategies that were undertaken were largely based on traditional regulatory disease control tools including:

• identification of infected flocks and flocks suspected of having ovine Johne’s disease
• restriction of movements from infected and suspect flocks, and
• zoning, which prescribes minimum disease control standards and requirements for moving animals to zones of higher status.

National Approach to the Management of Ovine Johne’s Disease in Australia (NAOJD) 2004-2007

The two-year NAOJD which commenced in July 2004 set the new approach to managing OJD through increased industry leadership and management, and fewer government-imposed restrictions. It provided a nationally agreed framework for the management of Ovine Johne’s disease in Australia. Responsibility for the ongoing operational management rested with the state governments and the national sheep industry. The national approach was coordinated by Animal Health Australia on behalf of stakeholders.

The new NAOJD had three main objectives to ensure that:

• areas currently free of disease remain free
• prevalence would be maintained or reduced for the Very Low Prevalence, Low Prevalence and Medium Prevalence Areas, and
• prevalence would be reduced in High Prevalence Areas such that prevalence area status may be reviewed in the longer term.

The three objectives were based on producers managing the risk of ovine Johne’s disease within their flocks and on assessing the risk of sheep that they buy. Vendors were strongly encouraged to declare the level of assurance of sheep they offered for sale and a Model Sheep Health Statement was agreed by Australia’s Animal Health Committee for this purpose. Data collected from surveillance activities undertaken during the NOJDP was used to estimate the current regional prevalence of the disease. This information was used to establish the Prevalence Areas, which were the basis for the allocation of credit points in the Assurance Based Credit (ABC) Scheme upon which the NAOJD was largely based.

Abattoir surveillance, used to monitor area prevalence, was funded by the Australian Government, the states and the national sheep industry, as were the national management and reporting functions undertaken by AHA. The states had responsibility for managing and controlling the disease within their respective jurisdictions.

The national sheep industry component was funded through existing levies contributed by all sheep producers and managed by the Sheepmeat Council of Australia. This funding contributed to R&D, abattoir surveillance activities, communication and program management.

Within the framework of the NAOJD the state governments provided:

• technical support for affected producers
• financial assistance through subsidised vaccination programs (in some states)
• ovine Johne’s disease management advice to producers, and
• state policies on ovine Johne’s disease management.

 OJD Management Plan 2007-2012

The Ovine Johne’s Disease Management Plan (OJDMP) was a significant component of the industry-funded National Johne’s Disease Control Program (NJDCP). The program was coordinated by Animal Health Australia to ensure the response to Johne’s disease by jurisdictions and industries continued to protect Australia’s favourable Johne’s disease status and reduced the impact of disease and control measures on the affected industries.

The OJDMP was the culmination of extended consultations between WoolProducers Australia (WPA), the Sheepmeat Council of Australia (SCA), state departments of primary industry and other stakeholders, and sought to further encourage producers to undertake risk assessments prior to the purchase of stock, in addition to controlling OJD through vaccination and on-farm management practices.

In seeking to establish a viable long-term approach to the management of OJD, industry determined that the principal aims of the OJDMP are to:

• minimise the risk to properties and geographic regions which currently appear disease free and actively manage incursions when they occur
• reduce the area prevalence in regions where the disease is endemic through the use of vaccine and the implementation of grazing management practices to minimise the exposure of stock to Mycobacterium paratuberculosis subsp. avium (Mptb)
• promote the benefits of active biosecurity planning at the individual property and regional level as a means of managing disease risk
• provide improved trading opportunities for producers who actively manage the disease through the use of the Assurance Based Credit (ABC) Scheme.

This business plan incorporated the following activities:

1. Prevalence Area determination
2. Points allocation
3. Abattoir Monitoring
4. Communication
5. Research and Development
6. Program Coordination and Evaluation

WPA and SCA have developed a program to provide a sustainable basis for the management and control of OJD in Australia. The OJDMP involves a rationalisation of existing prevalence areas from four to three prevalence areas and a subsequent change in ABC points allocated to each prevalence area. Risk-based trading and sufficient abattoir surveillance to underpin the ABC Scheme are seen as important aspects to the successful continuation of the program. WPA and SCA have also agreed to provide further funding for OJD research, and have identified a need for an ongoing communication program.

A management committee comprised representatives from WPA and SCA, other key stakeholders nominated by the national sheep industry, and Animal Health Australia meeting twice a year to oversee the program.