Developing the best virtual fence ear tag for cows

Student’s research yields optimal virtual fence ear tag for cattle

Emma Macon was a student from the grassy foothills of northern California’s Sierra Nevada when she enrolled at the University of Idaho.   

Chainsaws and crosscut saws were not tools she was accustomed to using, yet one of the first things she did as a Vandal was grab a chainsaw, a lumberjack crosscut saw and join the Vandal logger sports team. 

She eventually became president of the VandalJacks club team and represents the University of Idaho in her respective events as she competes at colleges and universities across the West from Montana to Colorado, and California to Oregon. 

“I was hesitant to join at first because it was definitely male dominated at the time,” Macon said. “I wasn’t a stranger to these chores because I grew up doing them and missed physical labor.” 

Macon, who was raised in the blue oak woodlands northeast of Sacramento wanted to study rangeland science, like her father who is a rangeland extension agent, and take part in research projects that would guide her career out of doors. 

“My sister and I spent a lot of time in the grasslands with my dad who we called a grass geek because he knew the names of all the plants,” she said. “So, I wanted a job working outdoors and the University of Idaho has a reputation for getting students the skills they need to do that.”

Working with Professor Karen Launchbaugh at the university’s Rangeland Center where virtual fence technology – which uses location devices on collars or ear tags of livestock to create a virtual fence that allows ranchers to control cattle without using barbed wire – is an ongoing concern.

Standard barbed wire fencing is costly to maintain, injurious to livestock, people and wild animals including elk and deer. It also fragments landscapes thereby disrupting wildlife migration patterns. Scientists are developing cost effective virtual – or invisible boundary - fences for better land management and wildlife conservation. 

Macon wanted to know what limiting factors must be addressed when outfitting cows with virtual fence ear tags.

“We wanted to learn what size and how heavy ear tags can be before they hinder cattle, and how small we could make them and still incorporate all the radio devices that are necessary to monitor and control cattle,” she said.

A cow’s ear only has so much real estate on it. Karen Launchbaugh, CNR professor

Working in the rangeland lab in the College of Natural Resources, Macon spent hours weighing prototype ear tags made of hard plastic that would contain radio receivers that used electric shocks to train cows to stay within boundaries. Last summer, she tested the various sizes and weights on cattle at the university’s Beef Center, monitoring behavior and side effects such as infections and ear injuries.

“A cow’s ear only has so much real estate on it, and putting extra weight on the ear can hurt animals, affecting their eating habits and movement,” said Launchbaugh. “Knowing just the right size and weight of a tag is really important.”

Macon is the first student researcher to consider ear tag size, weight and placement on the ear when applied to virtual fence research. She earned a Summer Undergraduate Research Fellowship (SURF) from the Office of Undergraduate Research (OUR) to conduct the research which is funded by the Dept. of Agriculture. The scholarship helped pay for travel costs as well as her time spent in the lab and out of doors monitoring the effects of ear tags on rangeland livestock.

The research will be compiled in a journal article, one of the few written by undergraduate researchers at the Rangeland Center.

“Emma will be only the second undergraduate student in 30 years to have a paper published,” Launchbaugh said. “That’s pretty powerful.”

While researching tag size, weight and placement, Macon considered the pain a tag may cause a cow, which changes animal behavior and may suppress grazing. She also explored ear damage, infection and tag retention – how long tags of various sizes stayed in a cow’s ear before they were dropped, broken or rubbed off.

"There were a lot of issues,” Macon said. “We needed to know the size and weight of a plastic ear tag that didn’t bother cattle and impede their behavior or their hearing, and the mobility of the ear.”

Working with U of I’s Beef Center on the Moscow campus, Macon tagged cattle and observed their behavior, collecting and narrowing down data to arrive at the optimal and most efficient ear tag size.

Macon’s virtual fence research is in conjunction with peers in the College of Natural Resources who are developing radio fences that are less costly than GPS-based models, weigh less than the collars that attach to cattle’s necks and are more accurate. GPS virtual fences are accurate to within about 10 yards, Launchbaugh said, while the radio tags are accurate to within a few feet.

“It’s 430 times more accurate”, Launchbaugh said. “It can be used as a fence, help lead animals to gates, keep them away from poisonous plants, and sensitive areas such as water seeps.”

Most virtual fence technology being developed uses collars weighted with batteries, Macon said. Using ear tags and radio beacons makes the fence technology low weight, low cost with high accuracy.

“Emma’s project is so critical,” Launchbaugh said. “Her work confirmed we’re on the right path.”

Joining VandalJacks was an important and exciting introduction into outdoor activities at U of I, Macon said.

“I fell in love with the team dynamic and camaraderie, and made a lot of friends,” she said.

But her virtual fence research has been the highlight of the senior’s college experience so far.

“I really enjoyed helping develop this technology that could be a real boon to ranchers, reduce the number of fences on the range and also be beneficial to cattle by not hindering them with heavy equipment,” she said.

Article by Ralph Bartholdt, University Communications

Photos by Melissa Hartley, University Visual Productions

Published in November 2024

This project is supported by Agriculture and Food Research Initiative Competitive Grant no. 2022-68017-37318 from the USDA National Institute of Food and Agriculture.