Comparison of different ultra-high-frequency transponder ear tags for simultaneous detection of cattle and pigs

AbstractElectronic animal identification is an important technology in modern animal husbandry providing great benefits. Low-frequency applications are state-of-the-art within the radio frequency identification of animals. Quasi-simultaneous detection of several animals and reading of the transponders over longer distances is impossible with low-frequency systems. Ultra-high-frequency (UHF) applications are suitable for this purpose. However, UHF systems have disadvantages through their susceptibility to metallic surfaces and liquids. Thus, the reflection and absorption of electromagnetic radiation in the animals' environment is often problematic. Consequently, an adjustment of the transponder ear tags regarding mechanical stability and functionality close to water (ear tissue) is necessary. In this project, targeted adjustments and a further development of UHF transponder ear tags concerning the resonance frequency were made. Three trials with cattle and two trials with pigs were performed in this study. Cattle were driven through a reader gate for ten rounds and six different types of transponder ear tags designed in-house were tested. The influence of the environment (indoor vs. outdoor), reader orientation at the gate (sideways vs. above) and output power of the readers (1.0 vs. 0.5W) were tested in two experiments. The average number of readings per round and the reading rates of the transponder ear tag types were taken as target variables. In the trials with pigs, three transponder ear tag types were compared. The animals were driven through the gate for five rounds per repetition, but neither the reader output power nor the reader orientation were varied. The pig experiments were performed indoors.The results of the cattle experiments showed that the average number of readings per round and the reading rates were significantly higher indoors compared to outdoors. The reader output power of 1.0W achieved significantly better results compared to 0.5W. The same applied to the reader orientation ‘above’ compared to ‘sideways’. It could also be shown that an improvement of the transponder and, thus, an adjustment to the animal's ear could be achieved during transponder ear tag type development. A maximum reading rate of 100% was reached with the cattle transponder types finally developed (B3-4, B4-4 and B5).In addition, an average reading rate of 100% was achieved for one pig transponder ear tag type (C2). However, these experiments have to be treated with caution due to a very low sample size