Simultaneous identification of fattening pigs using UHF RFID technology.

Currently used low frequency (LF) Radio frequency identification systems (RFID) systems for electronic animal identification can only identify animals separately rather than several animals simultaneously. Thus, animals have to pass the RFID reader individually for identification. Ultra high frequency (UHF) systems provide the opportunity to read multiple tags simultaneously. Due to their susceptibility to water and metal they are considered unsuitable for animal identification so far. But during the last years UHF transponders have been developed which are less susceptible to these disturbances as previous results show (Stekeler et al., 2011). The present paper describes trials on the use of UHF RFID systems for identification of fattening pigs. Two types of further developed UHF transponders were used to build two types of UHF ear tags (A and B). 12 piglets each were tagged with either a type of ear tag A or B. Two 1.1 m wide identification portals were installed in the alley of the feeding house using two types of UHF readers (I and II). Trials were carried out about the performance of the UHF RFID system over 14 dates during the growing and finishing period of fattening pigs. For assessment the identification rate of both ear tag types (A & B) and reader types (I & II) was calculated. Transponder type A achieved significantly reduced average identification rates than transponder type B (A: 45%, B: 57%; p<0.001). Reader I achieved significantly higher average identification rates than reader II (I: 55%, II: 46%; p<0.001). A significant impact of the combination of transponder type and reader type was observed (A.I: 61%, A.II: 29%, B.I: 50%, B.II: 64%; p<0,001). The results show that simultaneous identification of pigs with a UHF system is possible in very unsuitable situations. However, the identification rates achieved are not sufficient for practical work. But it was demonstrated that by applying the correct combination of transponder and reader the identification rates could be markedly improved.