We know that ID is coming — but how, and in what form? Many questions need to be answered, but nothing is likely to derail the march of RFID as the commonly accepted technology.
It’s the most logical way to go, says Dale Blasi, professor and extension beef specialist at Kansas State University. For one thing, an international standard already exists. “Australians and Canadians have moved ahead with this technology,” he says. “Given the lack of maturity in our system, we’ll probably go with the same thing. Canadians explored barcodes, but they were defeated in the packing plant. If you get a speck of dirt or hair on it, it simply won’t work.” Another disadvantage of the barcode was theline-of-sight requirement when it came time to read it.
Those were some of the factorsthat helped persuade the Canadian committee to move to RFID technology. The cost of an RFID tag — from $1.50 to $2.25 for large quantities — is more than a barcode tag. But there is no line-of-sight requirement and it works in dirty environments with the transponder or tag in proximity to the antenna. Of course, there are still a few flies in the ointment. Depending on the size of the antenna and how well the tag is tuned, the read distance can be anywhere from 0 to 40 inches for low-frequency RFID (what is currently the ISO standard under consideration by the NAIS). Another problem is that the readers cannot read a group of animals together. “You’ve got to present animals one at a time, single file, head to tail to the reader field,” Dr. Blasi says. “There are also materials around that can muffle the signal — water, steel, fluorescent lights in a packing plant. These materials can reduce read rates by as much as 70 percent.”
Manufacturers are trying to address what they call the anti-collision issues so that the reader would be able to read each tag in animals that were not necessarily single file. One way to get around the problem is with ultra-high-frequency technology. Wal-Mart, in its retail space, is moving toward that standard, which also offers a longer read distance. The technology would allow information to be written to the tags so that an animal could carry all its data with it. “We’re doing research with prototype tags now,” Dr. Blasi says. Dual-frequency tags, to work in both high- and low-frequency environments, might also be a possibility down the road.
Other ID technologies are receiving attention and may find a place in the developing system. Among them is retinal scanning, a technology that has already been around for a long time. The possibilities have been recognized since the 1930s with people; they’ve been used for entry into secure areas since the early 1970s. “It’s very powerful,” says Bruce Golden, CEO of Optibrand. “It’s the most informative among the human identifiers.” In livestock, research began in the 1990s when he was a professor at Colorado State University, and Dr. Golden and colleagues looked at different biometric identifiers.
A major advantage of retinal scanning is that it is literally unalterable; also, unlike tags, chips or boluses, there is nothing to attach to the animal that can get lost. “Ear tags are good for management decisions — sorting, and so on,” Dr. Golden says. “The kinds of ID we’re now talking about are about regulatory or contract compliance. It has to be admissible evidence. Ear tags have severe limitations. That’s why biometric identification is used in humans — it’s like the difference between a driver’s license and fingerprints. We need something highly reliable and relatively easy to acquire (unlike DNA). It’s unlikely that the Japanese will be completely happy with hanging an ear tag and signing affidavits.”
When it comes to eye biometrics, the retina and the iris are the choices. “We tried to work with the iris,” Dr. Golden says. “Cattle irises are not informative or very stable at young ages. Retinas are absolutely fixed.” The retina in cattle also has the advantage of being easy to acquire; they have large pupils and information-rich retinas with high contrast. Their images are easy for a computer to interpret. “And cattle have no aversion response to something in front of their eyes,” Dr. Golden says. “They don’t squint like humans do.”
A hand-held device acquires the image of the retina; it needs to be positioned in front of the eye for 1⁄ 19 of a second. “You can get an animal through in less than five seconds,” Dr. Golden says. “People talk about the speed of commerce. But we’re just as fast and a whole lot more reliable. I’ve participated in studies with 30-percent tag loss — they’re not average, but they’re not unheard of.”
As with barcodes, there is a line-of-sight issue when it comes to reading the retina, but there is no manufacturing cost for this technology other than the reader and the software. “The cost varies depending on the packages bought for managing data,” Dr. Golden says. It can range from 75 cents per animal for a calf ranch to 10 cents for a large packer.
DNA testing will never supplant RFID or any other type of real-time testing, says Calvin Gunter, director of corporate development for Bovigen. It’s a complementary tool to be used for quality control and to add an additional level of consumer confidence. Like retinal scanning, it is unalterable. “DNA’s use is to identify that an animal at one point in time is the same as an animal at a later point in time,” Mr. Gunter says. “And, unique in ID methods, it definitively crosses from live animal to the meat-production chain.” A DNA sample can be taken from any part of the animal or from a piece of meat.
DNA analysis could be used as a quality-control tool to verify that national ID systems are working appropriately. “What I would hope is that when an animal is tagged for the first time, a DNA sample is taken and sent to an archiving facility,” Mr. Gunter says. “On a regular basis, you could go to an animal or piece of meat and take a new DNA sample which could be compared to a sample sitting in an archive. It would go a long way toward ensuring customer confidence and would put us at the forefront of national identification and traceability systems around the world.”
Although you can obtain DNA from almost any part of an animal, some DNA can be analyzed more cost-effectively than what you often see in criminal cases or on TV crime shows. The cost of testing individual DNA samples is currently around $12 to $25. “As a secondary ID device to be used for quality control and to improve consumer confidence, it wouldn’t be necessary to test every sample,” Mr. Gunter says. “The applications in the beef industry for this technology are long and medium term. In the short term — there are a lot of other issues which need to be resolved first.”
Dr. Blasi agrees that DNA may have applications down the road. “Right now it’s too expensive, and there are turnaround-time issues.”
Microchips and boluses
Microchips and rumen boluses offer technology that has been proven for decades with pets and small livestock, says Elsie McCoy, manager of EZ ID Systems, which sells tags, microchips and boluses. There is a history with the technology, though the use has mostly been on a small basis by producers using it for their own benefit, as an alternative ID. Both methods are essentially tamperproof (short of operating on the animal).
In cattle applications, a couple of sites have been USDA-approved for injection of a microchip (the base of the right ear is most common for cattle). Migration of the chips is not an issue if they are injected properly, Ms. McCoy says, because the chip has a coating to invite tissue growth around it that holds it in place. The packer has to be informed that the chip is present so it can be extracted. Microchips can be easily injected with a syringe, but the read distance is short — just 5 to 6 inches. “The rumen bolus is the best choice for cattle,” Ms. McCoy says. “The read distance is greater.”
But the cost of microchips and boluses is around $6 or more. That’s one reason that their use will be limited, Dr. Blasi says — that and the need to implant the devices correctly. But he adds that what we end up with is likely to be some combination of methods as technology evolves. No technology is foolproof, and contingency plans will always be needed.