In 2009 and 2010, Rezare Systems undertook a number of trials of commercially available UHF RFID livestock tags and readers, looking specifically at performance in a wider range of situations than those supported by traditional low frequency RFID for livestock (typically referred to within the industry as electronic identification or EID).
Our trials were carried out in association with the New Zealand RFID Pathfinder Group, an incorporated society comprising mainly RFID users and supported by New Zealand Trade and Enterprise and GS1.
With the pending regulation of cattle identification and implementation of NAIT (New Zealand’s National Animal Identification and Tracing system), there was substantial discussion with regard to the standards to be used. While NAIT has selected low frequency EID for the present, industry partners were interested in investigating UHF technologies as longer term options.
In 2008 ANZCO Foods and the NZ RFID Pathfinder Group carried out trials with deer at Totara Hills Station, and with cattle and sheep at ANZCO Foods. Commercial “off the shelf” reading equipment was used, but the tags were constructed specifically for the trial, by gluing a UHF tag to a standard livestock tag. The results were promising for all species, including under wet conditions.
Our trials focused on testing commercial UHF tags and readers in on-farm conditions. At that time selection was limited, and we used tags from Invengo: 500 of these were imported at a landed cost equivalent to $2.50 per tag. We used a variety of readers from SICK, Intermec, Tracient and Motorola, with Intemec, Times 7 and Motorola antennas.
We had the tags assessed by Times 7, using The tags used were most optimised for the US 900MHz band (in New Zealand at the time we used a much narrower band at 868MHz). This means that under different conditions performance could be substantially better than we received. The male component of the tags was also too soft for reliable insertion in the animal’s ear. We ended up using Allflex male parts in combination with the Invengo EID tags, which worked well.
We read cattle, deer, and sheep one at a time through a narrow race, crate, or drafter. In all these situations read performance of the UHF systems was similar to LF, typically experiencing 96% to 100% reads of batches of animals. We noted that for cattle antenna size and position was important: body mass attenuates the UHF signal, which means that the tags did not charge and transmit well if there is too much body mass between them and the antenna (newer tags require less power so this problem may not be as obvious). We noted that a well-configured LF system performed as well (and occasionally better) in the single-animal at a time scenario.
We then trialled cattle, deer, and sheep running through a wide gateway. For sheep, a single panel suspended over the gateway was sufficient to reliably achieve 100% read of large mobs of animals moving at pace. However, for cattle and deer antenna positioning became far more important. We consider there were several factors that needed to be considered:
- As noted before, body mass attenuates the signal, meaning it is hard to “see through” a group of animals. We had better results when using two antennas (either two integrated send/receive antennas, or two pairs of send and receive antennas).
- When moving at speed, less time is available to charge and read the tags. Antennas need to be positioned to maximise the size of the read field in the direction of movement.
- When being driven forward at a moderate pace, livestock have a tendency to put their heads down. For cattle and deer in particular, this makes a substantial difference to their height, and needs to be considered when positioning overhead and/or side-mounted antenna.
In early 2010 we revisited these trials, working with ANZCO Foods and NZ RFID Pathfinder Group to demonstrate supply chain traceability for cattle and sheep – tagging animals with UHF tags on farm, and reading them on farm, onto the truck, off the truck at the plant, and at the stun box in the plant. The ANZCO team then followed the carcasses through the plant to boxed product which was delivered to a local retail operation – all traced using the EPC Global Network.
As expected, reading sheep on farm, onto and off trucks, and at the plant was a seamless and easy experience. One or two Intermec antennas readily covered loading races and achieved reliable reads, even using an Intermec IV7 reader on battery power.
We read cows in a single race and confirmed our earlier discoveries. We were operating in a high set of wooden cattle yards, and when the cattle were being moved forward some animals would put their heads down. We experienced the best results with a pair of antenna set to cover both high and low heights. When moving animals onto a truck the process was slower (as each animal had to be positioned on the truck, and there was no problem with reading.
We had significant challenge finding a place in the offloading area at the processing plant to read animals. Overhead spars were too high to read animals with their heads down. We considered that the approach we had taken for deer in earlier trials would have been effective: positioning a paired (send/receive) antenna on either side of the wide unloading race, angled so that they maximised coverage in the direction of movement of the animals. Alternatively, a single overhead antenna mounted in the covered loading ramp where animals are removed.
Finally, we read cattle as they reached the stun box. At that point we were surrounded by motors and other electrical equipment – an environment that is typically challenging for LF readers. Working in a very different set of frequencies, UHF equipment experienced no such problems, and we turned down the output power of the reader to avoid reading the next animal waiting to be stunned.
- UHF Supply Chain Report
- (A separate report on how the EPC Global Network was used with this trial was prepared by ANZCO Foods and the NZ RFID Pathfinder Group)
Funding for these projects and in-kind commitments was provided by: New Zealand Trade and Enterprise, ANZCO Foods, The New Zealand RFID Pathfinder Group Inc, GS1 Limited, Landcorp Farming Limited, Deer Industry New Zealand and The New Zealand Meat Industry Association. We also thank Allflex New Zealand for their interest and support in conducting on-farm trials and comparisons with LF readers.