RTLS Lets Pigs Roam Free

By Claire Swedberg

Two European farms have tested the active RFID animal tags, enabling farmers to track each pig's health and location, and a number of farmers will soon install them, according to the system's providers.

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Austrian wireless technology company MKW Electronics (MKWE) has completed trialing an active RFID system in two European pig farms in an effort to gain real-time visibility into each animal. The system is intended to benefit farmers as they prepare to comply with European mandates requiring livestock have communal free range in larger areas than in the single-animal holding areas currently in use.

The real-time location system (RTLS) includes 2.4 GHz active RFID tags complying with IEEE 802.15.4a standard, attached to the pigs’ ears, and receivers installed on the walls of the pigs’ covered premises, enabling farms to see where their animals are and receive alerts if their behavior has changed, signaling a possible illness or injury. The readers and tags are being provided by Nanotron with tag casings and system software provided by MKWE.

Nanotron recently developed its 2.4 GHz chip spread spectrum (CSS) NanoLoc series of small battery-powered RFID tags and readers for tracking animals, assets and people using a small tag and “anchors” that receive the ID number or other data encoded on the tag. One of its primary focuses is on the livestock industry, where changing European laws are making tracking of animals such as cows and pigs more challenging.

Nanotron’s Thomas Förste

Traditionally, livestock have been housed in enclosed small spaces, making it easy for farmers to monitor their health and overall condition and ensure the livestock don’t infect each other. However, EU laws pending for 2013 will require that farmers provide some level of free ranging for the animals, keeping them in larger communal pens. At some points, these animals will be harder to monitor visually since they will roam around a much larger space.

The NanoLoc tags transmit a chirp—a brief signal across the entire 2.4 GHz band. The chirps are received by the readers, with Nanotron software using the signal’s time difference of arrival (TDOA) to calculate each tag’s location within about three meters. The technology operates similarly, says Thomas Förste, Nanotron’s marketing and sales VP. The MKWE software then creates a record of the animal’s location and its movement patterns, analyzing how quickly it moves from one location to another. If those movements change significantly—for example if an animal that has been active suddenly becomes very inactive—the software determines that an alert needs to be sent to the farm’s managers, who can then physically visit the premises and identify whether an animal may be sick, need medication or need to be removed from the herd.

The technology, Förste says, can serve to save farmers the cost of antibiotics that might otherwise need to be injected in the animals proactively, to not only ensure that the pig does not develop an undetected infection, but also to ensure the other animals don’t contract it too.

MKWE trialed the system in two locations, one in Germany, the other in Austria, to determine how well it can monitor pigs. They chose to pilot the technology on pigs rather than cows because pigs posed the greatest challenges due to their small size. Both pig farming sites had the system installed in April 2011 and the pilots ran for one year, on a total of about 250 pigs.

The Austrian facility, which measures 26 by 24 meters, had six readers facing into the room and parallel to each other along two walls. In Germany, 12 readers were installed in a 20-by-34-meter space, with two installed on steel pipes in the middle of the space, and 10 readers attached to the walls.

The MKWE software tracked the location of each animal in real time and compared that data with the animals’ previous movements to detect when an anomaly occurred, such as no movement for a long period of time. The software was accessible via an Internet connection on either a PC or smartphone.

One of the challenges for Nanotron and MKWE was to ensure the tag was small and rugged enough to be worn in a pig’s ear. MKWE designed the tag to weigh 30 grams and have the life of the tag’s coin-cell battery to be close to the life span of the pigs (about two years).

“Pigs will tend to play with the tags,” Förste says, so the tag needed to be strong enough to survive biting and scraping from the animals. It also had to survive dirt, high humidity, ammonia, sulfur and hydrocarbon gases (all byproducts of pig excrement), as well as high impacts. Each tag was hermetically sealed with an IP67 plastic housing. After an animal is butchered, its tag could be cleaned and assigned to another animal.

The readers also needed to be rugged enough to survive a dirty and sometimes wet environment. They were also designed to be small—about 21 centimeters square.

After testing the system for one year, the pig farmers concluded that “there is currently no other comparable system,” says Förste. The greatest return on investment, he says, will be in allowing farmers to reduce the use of proactive medication, which he estimates may cost 20 to 25 euros per animal each year. In addition, he says, the use of tags would reduce the likelihood that an animal may become so sick it would have to be destroyed, since the symptoms of illness would be detected early. MKWE estimated that a farm could recoup the RTLS’ costs in about 18 months.

Förste says MKWE and Nanotron are in discussion with farmers in more than 20 locations throughout Europe, where the system will be installed “fairly soon.”