FMD changes could alter livestock markets

FOOT and Mouth Disease (FMD) is near the top of the list of exotic diseases to scare the public and governments. Many people have memories of the 2001 outbreak in Britain in which over 10 million sheep and cattle were slaughtered, or perhaps the 2010-11 outbreaks in South Korea when three million animals suffered the same fate.

The disease is highly contagious, affects a broad range of livestock and can be transferred relatively easily via water, air and animal products.

It is also responsible for massive trade barriers, with the world sharply divided into those with and without FMD. In fact the cost of these barriers is said to be far higher than the loss of production due to the disease itself, although nobody seriously argues for their removal.

FMD is also a tricky disease to control. While its impact is mainly on production and most infected animals recover, a few become long term carriers. The only way to prevent further outbreaks is to eliminate all animals that have come into contact with the virus.

The disease can be prevented by vaccination, although that is complex too. There are seven virus serotypes and over 60 subtypes. Vaccines against one serotype will not protect against another serotype, and may not be fully effective against subtypes within the same serotype.

Moreover, protection only lasts about six months and the inability to differentiate between vaccinated and infected animals (ie. both have antibodies in their blood) has meant that vaccinated animals must be slaughtered as the only way to ensure they were not carriers. In 2001, 250,000 vaccinated cattle in the Netherlands were slaughtered for this reason.

To make matters worse, the virus has a way of escaping confinement and causing outbreaks of disease, including via vaccines. In 2007 it escaped from a British research facility and infected neighbouring stock. Many FMD-free countries will not allow entry of the live virus under any circumstances

Vaccines are currently produced from FMD viruses propagated on cells, then chemically inactivated. In the past they have regularly contributed to outbreaks through contamination.

But times are changing. New vaccine and diagnostic technology is now becoming available that will soon transform control of FMD from vaccinate to die, to vaccinate to live, including in FMD-free countries such as Australia. The implications for world livestock production are enormous.

Probably the biggest change is the development of vaccines that cause a different antibody reaction from the live virus, accompanied by tests that can distinguish between vaccinated animals and those that have been infected.

When an outbreak occurs, vaccination can now be used to reduce virus circulation, for example by vaccinating all livestock within a buffer zone around an outbreak, while authorities continue to monitor its spread. Thus infected herds can be eradicated and non-infected herds protected.

Broad preventive culling of healthy vaccinated animals is no longer necessary, with culling restricted to infected farms. Importantly, if vaccinated animals are slaughtered, they can enter the food chain the same as other animals.

Highly valuable animals such as breeding stock, rare breeds, game parks and zoos can be vaccinated as a safety measure without hampering disease control schemes.

A quite recent development takes this a step further. A vaccine has now been developed that contains only part of the FMD virus and does not need the presence of the virus to be produced. The FMD fragment that stimulates immunity is generated using recombinant (ie genetically engineered) bacteria and then attached to a non-replicating adenovirus, which serves as a vector. This means expensive, high-containment production facilities are not needed.

And just to cap all that, a needle-free system for administering vaccines including FMD has been developed that is fast, safe and economical. That should make mass vaccination easier and safer.

Once the new vaccine is commercially available, Australia could safely manufacture and store its own supply, or maintain a supply produced in another FMD-free country, at relatively low cost and with no risk that it might contain the virus.

The cost of an outbreak in Australia could be limited by rapid mass vaccination of animals at risk of infection, with culling limited to herds confirmed to be infected. Highly valued animals could be subject to individual testing.

The door may be opened to the importation of vaccinated and test-negative animals from FMD infected countries, hugely expanding options for upgrading the gene pool of Australian livestock.

Elsewhere in the world, FMD infected countries will find it cheaper and easier to vaccinate their animals to bring the disease under control before embarking on a limited slaughter program of infected animals to achieve eradication. The eradication of FMD would have a major impact on food availability and diet quality in some countries.

And increasingly there will be countries that achieve FMD-free status and want a slice of the lucrative markets that Australia now supplies. The countries of South America have a target of ridding the entire continent of the disease by 2020. Right now, FMD-free regions in India have their eyes on the market in Indonesia.

Remaining competitive in the face of changing technology is not new for agriculture. And yet, every change in technology presents new challenges.

David Leyonhjelm is an agribusiness consultant with Baron Strategic Services. He may be contacted at reclaimfreedom@gmail.com

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READER COMMENTS

Percy
24/08/2012 12:25:17 PM

This again shows that our Australian quarantine status MUST NOT be compromised at any cost.
Agribuzz with David LeyonhjelmCommentary, news and analysis with agribusiness consultant David Leyonhjelm. Email David at reclaimfreedom@gmail.com

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#blueysmegacarshowandcruise2019 10 years on Daniels Ute will be apart of another massive cause.
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Australia's live animal trade is nothing but a blood stained industry that suits those who