Tracking Cows
By Wendy Grossman, Thu Jan 23 08:30:00 GMT 2003

Wireless technologies will help make tracking herds of cows - and their diseases - easier and faster. Mooooooo!


The discovery of Bovine Spongiform Encephalopathy (BSE) in British cows in 1986 (and those of other countries since) inspired the European Union to adopt systems to track cattle and other large animals throughout their lifetimes.

The point is not just preventing the spread of BSE. An important part of containing any disease (such as last year's outbreak of foot and mouth disease) is ensuring that the outbreak can be tracked quickly to its point of origin and any other animals that may have been infected can be traced promptly.

Cows born in the UK have been tagged since June 1996. Before then, although farmers traded information about cattle movements, there was no central system. The information encoded on plastic tag includes such basics as the newborn calf's state of health, its ownership history, and the veterinary treatments it receives. It is made into a paper passport that is administered by the Department for Environment, Food, and Rural Affairs (DEFRA). Under EU regulations, cows may not be sold in Europe without passports.

Behind the passport system lies a centralized database in each country that tracks the cow's life from birth to slaughter. Similar identification and tracking systems have been adopted by many other countries, such as the US and Australia, that want to be able to sell meat into the EU.

Increasingly Important


Wireless is not yet a factor in any of this, but it is likely to begin to play an important role in the next few years. The first step is to move from today's large, plastic ear tags, which are usually read by either barcodes or the human eye, to electronic ID (eID) tags. These became legal for use in the EU as of 2002, but they are some way from being adopted - they are not yet, for example, legal in the UK.

This sounds odd at first, but the reasons become clearer when you talk to Richard Webber, managing director of Shearwell Data, the UK's market leader in this field.

The current system requires cattle to have a plastic tag inserted in each ear within seven days of being born. The primary tag is meant to be large enough to be readable at a distance - with binoculars, say. The secondary tag is a bit smaller, about 25mm in diameter. The idea of having two is, of course, to ensure that the cow will have at least one tag at any given time. The tags are read by the farmer when a cow is moved, sold, treated, or sent for slaughter, and the information is entered into paper forms that are then sent to DEFRA for processing. Clearly that makes for a labor-intensive and costly system both for government and farmer. Yet everyone agrees it's necessary if we are to be able to trace disease outbreaks to the source and choke them off quickly.

Philip Yam, author of the forthcoming book "The Pathological Protein: The Emerging Danger of Prion Diseases," says that tracking the movements of cows is a good component to have in the fight of BSE, for example. "A high-tech system of tracking could quickly identify other cows that may also be infected. It may also help you find the source of infection. Speed would certainly help - in Japan, it took nearly four weeks to confirm the first BSE case there, by which time the infected cow had been turned into feed and presumably fed to other cattle." Yam says, however, that it may be more important to control what happens to the feed derived from cows.

Current Difficulties


But the present system is difficult for all concerned. Steve Rawlings, for example, a small farmer in Telford who raises a particular breed of smaller cows known as Dexters, says, "Personally, I cannot wait to see electronic tags introduced. "I find the existing government-approved tags a nightmare, especially with the Dexters, as the calves are so small when born."

In practice, says Rawlings, the tags just don't work out the way they're supposed to. "The tags break, get cut, and also just rip out of the ear. It's not nice, and it's a real pain to replace." In addition, the requirement to have both tags present when the animal is slaughtered means that quite often the cow has to be re-tagged just before it leaves the farm, adding to the stress for both animal and farmer, he says. Finally, because the Dexters Rawlings breeds are very small (for cows), he has particular trouble tagging them when they're newborn.

Not all of this can be solved by switching to electronic tags, but a good bit of it can. EIDs can be inserted into animals in three ways: in a bolus that the animal can swallow that stays in the animal's stomach throughout its life (in cattle, Webber says only one in 2000 gets lost); an implant that can be inserted under the animal's skin; or as an ear tag. At present, he says, trials of eIDs in the UK are focused on sheep and pigs, because of the need to track these animals after the 2001 outbreak of foot-and-mouth disease (FMD); the intention is also to eradicate scrapie in sheep. Preliminary reports from the trials suggest that the bolus method is the most reliable, both for retention and for reading.

The big advantages to eIDs ought to be obvious. The rate of loss of the tags themselves is much lower. The fact that the tags can be read by radio with the data going straight into the database means they can be read automatically, cutting out the lengthy manual process and making it possible for farmers to garner much more information from the data they collect. This all works simply enough: the tags contain a passive transponder that is woken up when the reader sends it a signal. The chip retains just enough energy from the signal to send back its unique 16-digit number, which is then passed from the reader to the handheld stock recorder and thence into the database. Problems such as dirt obscuring the ear tags are no longer an issue.

The Hurdles


But there are many hurdles to cross before eIDs can replace today's plastic tags. As Webber himself says, "eID is a good idea, but it's not marvelous."

The first problem is that a database has to be prepared to accept the data, which is not expected to happen until 2006 or 2007. This sounds like a long time, but consider: the average age of the UK's 80,000 farmers is 58. Many are not computer-literate and have no interest in becoming so. So whatever system is devised must be extremely simple to use and very robust. It also will have to be forgiving of technical glitches such as, for example, dead batteries or inadequate memory in the handheld being used to accept the data, and be able to reconcile conflicts such as different groups of data arriving at the same time. This can happen when, for example, animals on the way to the abattoir are read with a handheld but the kill sheet is sent straight to the office and entered before the handheld's data is uploaded.

At the moment, the connections between reader and handheld are typically cables; there's a great desire to replace this with a wireless connection, since sheep in particular like to eat cables, and in farm conditions it's easy for animals to dislodge the connection or water to get in and disrupt communications without the operator's realizing it. For situations like these, wireless can't come soon enough.

Reading the eIDs isn't entirely straightforward, either. Animals are frequently read in a race reader - that is, a structure that moves the animals through in single file. The eIDs cannot be read at all if they are at right angles to the reader's antenna. Using multiplexed antennas that send the signal from more than one angle is a solution to this, but it remains an extra problem. A system is therefore needed to fill in the holes if animals are not read at points along their passage. For example, say you're moving 1,000 sheep from one farm to another, and two of them appear on the first farm list, not on the lorry, but then again on the second farm list. Clearly they had their tags along the way.

Considerable Savings


Despite these problems, the savings for farmers of using eIDs could be considerable - perhaps as much as 14 man-days less labor to test a herd of cattle for TB.

Webber himself, who raises 25,000 sheep as a sort of weekend hobby, says he looks forward to being able to collect better data on his animals. Automating data collection, he says, will make it possible to review how much a particular animal has cost him in veterinary treatments and breed the herd selectively for criteria such as worm resistance, general health, or physical quality. In addition, he has his eye on a Nokia 9210 communicator that would let him look up prices elsewhere while he's physically at the market buying livestock. All these things may seem like small savings, but such is the economic state of British farming that a small farm can't afford employees - and anything that can streamline the arduous process of meeting the regulatory requirements or shave a bit off costs is sorely needed.

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Wendy M. Grossman is a freelance writer based in London, and author of net.wars. Her new book, From Anarchy to Power: The Net Comes of Age is out.