Beefing up against cattle disease
UQ researchers have developed a vaccine that could slash the devastating impact of Bovine Respiratory Disease on cattle and the beef industry.
Although many Australians consume beef regularly, we don’t necessarily make the direct link between what we buy at the supermarket and the Australian cattle industry – a multi-billion dollar industry that bolsters the economy and supports thousands of jobs for Australian farmers and rural communities.
Approximately one million cattle in the Australian beef industry are contained in feedlots, where they are fed a controlled diet so they satisfy meat industry requirements.
The Australian cattle feedlot industry is relatively new, and growing at a rapid rate.
But one cattle disease is curbing that growth and causing national losses of up to $100 million a year.
Bovine Respiratory Disease (BRD) is a topic well-known by Professor Tim Mahony, from UQ’s Queensland Alliance for Agriculture and Food Innovation (QAAFI) Centre for Animal Science.
“BRD is caused by a combination of three factors – stress, a viral infection, and a bacterial agent – and is most commonly found in domestic feedlot cattle,” Professor Mahony explains.
“Cattle may experience stress in a range of situations, including when they’re handled, transported, introduced to new cattle, or exposed to new environments.
“This stress can depress their immune system, making them more susceptible to BRD.”
The symptoms of BRD resemble those of the flu in humans – dull eyes, decreased appetite, breathing difficulty, droopy ears and depression – and can be fatal.
It is a major concern for feedlot operators and cattle producers in the North American industry and, despite years of research, there has been little success in reducing its impact.
The Australian feedlot industry has an advantage though – because it’s younger and smaller, researchers and producers have been working together to manage BRD as the sector is growing, rather than retrospectively trying to control the problem after it has become unmanageable.
Historically, testing the effectiveness of new vaccines has been relatively simplistic – administer the vaccine or treatment to a population, expose them to the virus of interest, and monitor their health.
As these vaccines generally do not prevent infection, the differences between vaccinated and unvaccinated animals can be small.
Consequently, these experiments require large numbers of animals to determine if the vaccine is effective.
Professor Mahony and his team therefore developed the dual pathogen challenge model, a technique testing the effectiveness of the vaccine by accentuating clinical signs severity in unvaccinated versus vaccinated individuals.
However, because the model lacks the third component of BRD development – stress – trial animals do not develop severe or fatal disease.
In trials completed with the assistance of staff at the Queensland Animal Sciences Precinct at UQ’s Gatton campus, vaccinated and unvaccinated cattle were sequentially exposed to challenges with viral and bacterial agents associated with BRD.
The team then evaluated how effective the vaccine was by looking at the severity of BRD symptoms in the cattle. Unvaccinated cattle demonstrated mild BRD symptoms, while vaccinated cattle had even milder or no symptoms from the bacterial infection.
“The secondary bacterial challenge component means the unvaccinated animals develop only a mild clinical disease like coughing or lethargy, but we don’t see many, if any, of these signs in the vaccinated individuals,” Professor Mahony says.
“The clinical differentiation between the treatment groups is far more distinct and robust [in comparison to traditional vaccine trials], which ultimately means we can use fewer animals in the trials to generate more meaningful results.
“We believe the dual pathogen challenge model will translate into improved and sustained disease control in the field.”
This is only the beginning of the BRD vaccine journey for Professor Mahony and his team.
They hope to identify other pathogens that are involved in the onset of BRD in Australia, and extend the scope of their current BRD vaccine platform as far as possible for feedlot cattle.
The team is also keen on taking advantage of the platform given to them by a commercial partner to tackle BRD on an international scale, where annual losses are currently estimated at $2.5 billion.
A critically important outcome of preventing BRD will be a reduction in the use of antibiotics to treat affected cattle.
The vaccine will also immensely benefit those who breed cattle for extensive raring or for sale into the feedlot sector.
While the cattle-producing sector is a separate beast to the feedlot sector, both industries face productivity losses due to the pathogens associated with BRD; with the former losing an estimated $115 million in Australia each year in reproductive losses due to bovine pestivirus, also commonly linked to BRD.
While the use of the vaccine in non-feedlot systems will probably occur in a different time frame, the vaccine has the potential to revolutionise the beef industry.
“Better vaccines are crucial to improving the long-term profitability and sustainability of Australia’s livestock industries, which lose over $3 billion annually to pests and diseases,” says Professor Mahony.
Progress to date:
1998: Industry recognises new approaches are required to address Bovine Respiratory Disease
2002: Professor Mahony and team develop a vaccine delivery platform capable of targeting multiple pathogens at once
2002: Professor Mahony and team lead discussions with industry to communicate their research results
2004: Professor Mahony and team successfully construct a prototype vaccine
2004: The team files and is awarded a patent on the vaccine technology – this primary and protected position was crucial for potential partners
2005: Professor Mahony and his team develop a multifaceted dual pathogen challenge model to evaluate vaccine effectiveness
2007: The team consult widely with veterinary pharmaceutical companies to understand their expectations in new technologies
2007–2015: Trials demonstrate the prototype vaccine effectiveness using a dual pathogen challenge model
2007–ongoing: Consultation with relevant regulatory authorities regarding a new type of vaccine
2015: The team is awarded the patent on the vaccine technology in Australia and other jurisdictions, while the patent for the United States is in final stages
2016: Commercial partner is identified to progress the prototype vaccine through to registration
2017: Contractual negotiations undertaken for the licensing of the prototype vaccine to commercial partner
2018–19: Planning to transfer prototype vaccine to commercial partner for further development and evaluation
Acknowledgements: The Queensland Alliance for Agriculture and Food Innovation (QAAFI) is a research institute of The University of Queensland (UQ), supported by the Queensland Department of Agriculture and Fisheries. This research is funded by UQ, the Queensland Department of Agriculture and Fisheries, Meat and Livestock Australia with matching funds from the Australian Government and grant projects B.FLT.0203, B.FLT.0224 and B.FLT.0232.
Queensland Alliance for Agriculture and Food Innovation
- Queensland Alliance for Agriculture and Food Innovation (QAAFI): Carolyn Martin, firstname.lastname@example.org or 0439 399 886.
- Meat and Livestock Australia: Josh McIntosh, Media Manager, email@example.com or 0404 055 490.
- Queensland Department of Agriculture and Fisheries: Mark Hodder, DAF media, DAFMedia@daf.qld.gov.au, (07) 3087 8598 or 0421 618 871.