"Retinal scans are part of a growing technological trend in cattle identification," said Manny Encinias, livestock specialist at NMSU's Clayton Livestock Research Center. "It painlessly flashes a beam of light into the eyeball and records the pattern of veins in the eye."
Each retina, whether bovine or human, is unique and a scan is considered one of the most accurate forms of identification, he said.
The NMSU evaluations are part of an accelerating effort by the U.S. Department of Agriculture to implement a National Animal Identification System. The goal is to track and identify all animals and premises that have had contact with an animal disease of concern within 48 hours of an initial diagnosis.
In a first-of-its kind project for New Mexico, scientists tested 35 market steers from 18 Quay County farm families, using a combination of eye-scanning and radio frequency identification (RFID) ear tags for animal ID evaluation. Most of the cattle were high-value 4-H and FFA show cattle that spent much of the past season moving between regional livestock fairs.
Encinias used a $3,000 retinal scanner not much bigger than a small video camera to record the IDs at three locations over a six-month period. To make the digital record, the cow is held in what's known as a squeeze chute and the scanner's eye-cup, specially molded for a cow's face, is held to each animal's eye.
The scanner senses when the eye is open, automatically makes an image, and downloads the data to a computer database. In addition to the retinal image, the device records the date, time and a global positioning satellite coordinate of the location.
"It's as simple as taking a picture," Encinias said. "Plus, we can do everything at chute side."
Historically, 4-H and FFA exhibitors have been required to submit hair samples for DNA analysis to serve as a permanent means of identification. "DNA analysis is costly and requires a complex laboratory procedure that takes time," he said. "Also, hair samples have been lost in transit."
Among the show cattle, researchers found that the retinal scans proved a near-perfect animal ID technology because of its speed and accuracy, Encinias said. However, the eye-scans might not be practical on a working ranch due to cost and technical skill required.
Separately, NMSU experts examined RFID tags alone on several hundred cattle on a communal grazing allotment in the Valles Caldera, an 89,000-acre area in the Jemez Mountains. Communal grazing allotments are typically seasonal, running from May to October.
"We wanted to show the small-scale producers of northern and central New Mexico that this animal ID technology will work for them, too," Encinias said.
The $2 tags contain a unique 15-digit electronic code identifying each animal like a Social Security number for life. Located on the cow's left ear, the tags are about the size of a bottle cap. With more than 900 RFID tags applied since May, only two have been lost.
Using a panel tag reader located on a cattle chute, researchers found that the RFID tags could be readily read as cattle passed through a single-file alley. Effective range for this particular electronic reader was about two feet.
"A prime goal was not to slow down the normal production process, and I think we did that," he said. "We maintained a single-file, continuous flow with a reliability rate of more than 93 percent. It's not 100 percent, and that's something we're working on."
The animal ID projects, which were conducted in cooperation with the state veterinarian's office and the New Mexico Livestock Board, were funded through a USDA grant, and were designed to evaluate the technology specifically for New Mexico' s varied production environments.
"We need to have producers on board and comfortable with ID technology because it's inevitable that it's coming to New Mexico," Encinias said.
When the idea of mandatory cattle identification was introduced several years ago, cattle producers were concerned about expense, inconvenience and loss of privacy.
But experts stress the importance of controlling cattle diseases before they get out of hand, said Clay Mathis, a livestock specialist with NMSU's Cooperative Extension Service. Even though the new system will cost producers more money, it will eventually mean the full tracking of animal movement throughout the nation, he said.
The announced USDA target for a mandatory animal identification program is January 2009, said Ron Parker, an animal ID specialist with NMSU Extension and the New Mexico Livestock Board. At that time, all animals entering marketing channels must be identified.
Now, a final report on both NMSU animal ID technology studies is being compiled for USDA, Encinias said."In the future, we need to look at just how long the RFID tags last under New Mexico's varied and sometimes brutal climate conditions," he said. "And, we need to see how these ID technologies work at the sale barn and other commingling areas."