Minimising bovine respiratory disease (BRD) in Queensland feedlots
21 March 2023
By Jason Strong, Managing Director, MLA
Meat & Livestock Australia (MLA), within our feedlot program has a large R&D focus on preventative, diagnostic and extension measures for minimising the impact of bovine respiratory disease (BRD).
Bovine respiratory disease (BRD) is the most common cause of illness and death in Australian feedlot cattle. BRD is caused by a combination of stress and disease-causing agents, including viruses and bacteria.
The preventive measures currently being assessed by MLA include:
- development of new vaccines
- improving diagnostic technologies
- updating the Bovine Respiratory Disease Preventative Practices handbook for industry.
Autogenous vaccine evaluation
Autogenous vaccines are custom vaccines produced from bacteria isolated from animals at the source feedlot to stimulate immunity against those strains included in the vaccine.
MLA has joined forces with the University of Adelaide’s Associate Professor Kiro Petrovski and Apiam Animal Health’s Dr Tony Batterham, to evaluate if autogenous vaccines approved by the Australian Pesticides and Veterinary Medicines Authority (APVMA) confer additional protection from BRD.
This project, which will commence this year and conclude in December 2024, will deliver three large scale randomised block-controlled studies investigating one or two shot autogenous vaccine protocol for combined P. multocida and H. somni and a M. bovis autogenous vaccine.
We are currently determining which sites will host the trial, as well as identifying the vaccine strain candidates. This will be followed by regular surveillance and testing of those specimens thereafter for the duration of the project.
The vaccines are tailor-made to each feedlot site who are providing source material. However, they require ongoing surveillance of the bacterial pathogens operating.
This does align with good antimicrobial stewardship practices, delivering a win-win to operators and customers.
Emerging diagnostic technologies
Alongside vaccines, diagnostic technologies are an essential way to minimise and prevent BRD in feedlot cattle.
An ongoing project between MLA and Charles Sturt University (Charles Sturt) through the Gulbali Institute of Agriculture, Water and Environment, in collaboration with NSW Department of Primary Industries (NSW DPI) is looking to quantify the cost of disease in feedlots including losses associated with carcases condemned with BRD.
The project uses quantitative real-time polymerase chain reaction (qPCR)-based diagnostic methods to identify a range of pathogens related to BRD, within the same day, allowing this to be used for whole mob decision making
Through Charles Sturt’s tests so far, we have found that these diagnostic tests show a quantitative concentration of potential pathogens in an animal.
The reason this is important, is because this can show which animals are at risk of BRD before they get it.
The technology development, led by Dr Ian Marsh at the Elizabeth Macarthur Agricultural Institute, is now in the final stages of testing. The project is now undertaking an economic analysis and intervention modelling to understand how the tests can be practically incorporated into a commercial feedlot.
Bovine Respiratory Disease Preventative Practices handbook – 2021
MLA is also committed to providing easily accessible information for Australian beef feedlot organisations and processors around BRD.
In 2016, MLA published the ‘Evaluation of practices used to reduce the incidence of bovine respiratory disease in Australian feedlots.’ In 2021, MLA worked with Dr Paul Cusack at Australian Livestock Production Services (ALPS) to develop an updated handbook for the industry.
The updated handbook will contain new information relating to environmental, animal and management factors that affect the incidence of BRD in lot fed cattle published between 2016–2021.
Since the initial document was written, various new developments in peer reviewed literature and industry best practice have emerged. We want to make sure that these important developments are captured in the updated version.
Although the information is deeply technical, it can really prove to be the world of difference to you, your cattle and your business.
