Retention and readability are two words to bear in mind when placing radio-frequency ID (RFID) tags in the ears of your cattle.

“The most common problem we've experienced is producers placing tags on the top of the ear,” says the University of Kentucky's Jim Akers. “The ear is thicker on top and gets thicker as you move toward the head. The problem occurs when producers jam the tags up against the head of these cattle.”

Akers is working with the Southeastern Livestock Network (SLN) pilot project (see page 24). He says improper placement can affect tag retention and cause infections from compression necropsy in the ear.

“On one occasion, we had to cut out and replace tags on 500 head because the tags were put in too close to the head and caused infection,” he says.

Manny Encinias, a New Mexico State University Extension livestock specialist in Clayton, observed similar problems. He's working with 68 producers in the Tri-National Livestock Health and ID Consortium.

“With the exception of one producer, these volunteers had never applied an electronic tag,” Encinias says. “I sent the tags with the applicators and gave them a picture of where I wanted the tags placed. Of 800 tags sent out, we've only lost two.”

But, he adds, there were a few mishaps during the initial stages of the learning process. These ranged from applying tags backwards to too close to the head, causing abscesses and infections.

One SLN goal is to test tag sites and measure their readability and retention. Akers is working with 100 Kentucky herds, in different topographies, using various fencing and management systems.

“We have other control tests that have been underway for four years,” he adds. “We go in twice each year and monitor the herds. We check if the tags still work and for lost tags. We've varied tag placement — some placed on top of the ear, some in the middle lobe, some closer to the head and some farther out.”

Readability problems due to placement haven't been encountered, though there's been “a little reduction depending on the system when we have tags in the upper placement,” he says. “I think a few panel systems don't work as well with that orientation, but we haven't seen any huge statistical difference.”

Testing readers

Encinias says he's working with New Mexico livestock inspectors in testing both handheld and panel readers. While the studies aren't official, some observations may be important, he adds.

For instance, one red flag popped up in testing a continuous-flow system using panel readers. The average of tags successfully read was 93%.

“When we examined the video shot during the test, our only conclusion was some tags were placed in the top of the ear, closer to the head,” Encinias says. “On more of a horizontal surface like that, the tags didn't read as well with the systems we were evaluating.”

Encinias recommends producers place tags in the middle lobe, two to three finger widths from the outside of the ear. Akers adds that the official RFID tags should be placed in the left ear.

“We're trying to communicate the left ear is the industry-accepted standard,” Akers says. “It improves read rates. And it the minimizes reader investment for markets and feedyards.”

Recognizing all official forms of ID from other countries is as important as establishing consistency in tagging animals in the left ear in the U.S. system, Encinias says. For example, New Mexico and other southern-tier states receive cattle from Mexico tagged with official Mexican ID tags. Most of those tags are cut out upon reaching the U.S.

“Mexico has systems to trace cattle back to herd of origin. But we lose all that info if the tags are removed,” Encinias says. “We have to educate people to recognize other countries' tags.”

He says producers he's worked with are beginning to embrace the technology, but there's still a long way to go.

“The whole system has to be 100%,” he says. “Because if it's not 100%, I don't think there's a reason to do it.”

Akers says that he believes 100% is unrealistic because of the changes that would have to occur in producers' business practices to facilitate that goal.

“The costs of going beyond 96-97% would be damaging to our marketing infrastructure,” he adds.