Electronic Ear Tags for Tracing Fattening Pigs according to Housing and Production System
Frank Burose1, Thomas Jungbluth2, Michael Zähner1
1 Agroscope Reckenholz-Tänikon Research Station ART, Tänikon, CH-8356 Ettenhausen, Switzerland, frank.burose@art.admin.ch
2 University of Hohenheim, Institute for Agricultural Engineering, 70593 Stuttgart, Germany
Abstract
Electronic labelling is necessary for automatic, individual tracking of pigs. To ensure unique identification of animals, the label must remain in place and its functional reliability must be assured.
The loss rates and performance of one plastic and three electronic ear tags were analysed on 16 commercial farms in two different housing and production systems in each case. A total of 9,325 experimental animals were examined from the application of the ear tag in the suckling period until the end of the fattening period.
The functional reliability of the electronic ear tags was very good. On average, only 1% of the ear tags on all commercial farms proved defective by the end of the fattening period. The ear-tag loss rate ranged from 0.2% to 19.4%, with a mean value of 2.8%. There were no significant differences between ear-tag types and housing and production systems in terms of either functional reliability or loss rates.
Keywords
Electronic ear tags, Electronic identification, Ear tag losses, Fattening pigs.
Introduction
The Swiss Animal Disease Act makes it compulsory to apply an ear tag to pigs no later than at the time of weaning. Without the use of electronic systems, registering and recording the movement of livestock entails high administrative costs. To enable complete traceability of the animals from birth to slaughter, it is essential that the ear tag remains on the animal. The animal must still bear the ear tag when it leaves the fattening farm in order to enable it to be positively identified at the abattoir, assigned to its individual slaughter result, and finally, traced back to the farm where it was born.
Nowadays, slaughter pigs are tagged with a plastic ear tag and recorded in groups. To enable individual tracking of the animals, the labelling medium must be uniquely coded.
The aim of this study was to analyse the loss rate and functional reliability of three electronic tags and the official plastic ear tag on Swiss working farms with different housing and production systems.
Material and methods
Piglets were labelled with different ear tags on 16 farms. Pig farmers were assigned to different categories according to their housing and production systems. Farms producing pigs for a label programme or according to the requirements of the Swiss Meat Quality Management scheme were assessed. The classification was derived from the different housing requirements of the animals during the lactation, piglet rearing and fattening periods. In addition, the farms could be subdivided into two production systems. We investigated farms working with closed systems (i.e. those which fattened their own piglets) as well as those specialising in at most two of the three production stages (piglet production, piglet rearing, pig fattening) in the fattening-pig production sector.
The official plastic ear tag of the Animal Tracking Database (TVD, Fig. 1, right) and three different electronic ear tags were tested. Besides standardised ear tags (ISO 1, ISO 2; Fig. 1, 1st and 2nd from left), a prototype was used whose transponder contained an anti-collision algorithm (AK, Fig. 1, 2nd
from right). This algorithm allowed for the virtually simultaneous identification of several transponders by means of a single reading antenna (Finkenzeller, 2002). The electronic component of all three ear tags, consisting of a coil and microchip, was in the female part of the ear tags in each case. Printed on each male part were the seven-digit farm identification number of the piglet producer and a consecutive four-digit number. An ear tag was applied to each of the 600 animals in an experimental group.
Figure 1. The electronic and plastic ear tags tested.
The loss rate of the plastic ear tags was checked visually, whilst the loss rate and functional reliability of the electronic ear tags were checked both visually and with mobile reading devices.
Documentation took place during the production process, upon ear-tag application during the lactation period, at the beginning of the rearing and fattening stages, and before the animals were sold for slaughter.
Loss of an ear tag is defined as the absence of an ear tag where there is a visible hole in the ear. For the assessment of the functional reliability of the three electronic ear-tag types, a distinction was drawn between a positive and negative reading result. In the event of the non-reading of the transponder, the state of the ear tag was examined more closely. Here, three situations involving defective ear tags were described:
- Ear tag broken in two;
- Ear tag scratched or deformed (damaged); and - Ear tag outwardly normal (defective).
The statistical evaluation was performed with a two-factorial analysis of variance.
Results
Loss rate of ear tags
Ear-tag losses in the piglet-rearing period were identified on nine out of 16 farms (Fig. 2). In total 64 piglets (0.7%) had lost their ear tags in the piglet-rearing period. The spread across the four different
ear-tag types (TVD; ISO 1; ISO 2; AK) yielded a highly uneven pattern. Whereas the TVD ear tags accounted for 4.7% of losses, electronic ear tags constituted between 14% and almost 61% of losses (ISO 1 and ISO 2, respectively). Two of a total of nine farms with ear-tag losses were responsible for 44 (68.8%) of the 64 missing ear tags (Fig. 2).
0 4 8 12 16 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Farms [n]
Loss rate of ear tags [%]
Fattening Piglet rearing
Fig. 2. Ear-tag losses at the piglet-rearing and fattening stages.
In the 'fattening’ production stage, 15 of the 16 commercial farms suffered ear-tag losses. All in all, 191 ear tags (2.1%) fell out of the piglets’ ear holes. These losses were distributed more evenly among the individual ear-tag types than in the piglet-rearing period. The percentage of TVD, ISO 1 and AK ear tags lost was between 15 and 19%, whilst the ISO 2 ear tags accounted for nearly 48% of all ear-tag losses. The two farms with the highest ear-tag losses in the piglet-rearing period also accounted for nearly 2/3 of all losses during the fattening stage. Together with a third farm, they are responsible for over 80% of ear-tag losses.
There were no significant differences between the four ear-tag types and the two housing and production systems in each case in terms of ear-tag loss rates.
Functional reliability of electronic ear tags
Technical failure was identified in a total of 31 ear tags (0.5%) during the piglet-rearing period, with half of the 16 commercial farms being affected (Fig. 3). 71% of the technical failures occurred with the ISO 2 ear tag, and a further 19% with the ISO 1 ear tag. It was striking that 21 (68%) of the 31 technical failures occurred on just two of the commercial farms. Of the 31 ear tags subject to technical failure, 23 (74%) broke apart, and eight (26%) were defective.
0 1 2 3 4 5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Farms [n]
Technical-failure rate [%]
Fattening Piglet rearing
Fig. 3. Technical failure rate of electronic ear tags at the piglet-rearing and fattening stages.
During the fattening stage, 33 electronic ear tags (0.5%) were subject to technical failure. The ISO 1, AK and ISO 2 ear tags were responsible for 46%, 33% and 21% of technical failures, respectively.
For the ISO 1 ear tag, 13 of the 15 ear tags were defective, and two were damaged. With the ISO 2 ear tag, four out of seven technical failures were caused by the ear tag breaking apart. The 11 defective AK ear tags were either outwardly normal, or had broken in two. Five farms were free from ear-tag functional failures during the fattening period. Moreover, no negative readings had previously been recorded in these groups during the piglet-rearing period.
There were no significant differences between the four ear-tag types and the two housing and production systems in each case in terms of technical failure.
Discussion
The loss rates and technical-failure rates of both plastic and electronic ear tags on pig-fattening farms were markedly lower in the present study than in a study carried out by Caja et al. (2005): whereas in Caja’s study, the two types of electronic ear tags tested exhibited a loss rate of 8.8% and 44.9%, respectively, only 2.0 to 5.9% of the electronic ear tags went missing in the current investigation. At 1.3% and 1.0%, respectively, the plastic ear-tag loss rates were on the same level. Standing at 5.5%
and 55%, respectively, the technical-failure rates of the electronic ear tags were markedly higher for Caja than for the present study (0.6-1.3%).
The results portrayed are only to a limited extent comparable to those of Caja et al. (2005). The number of tested ear tags was approx. 20 times greater and the number of tested animal groups 16 times greater in the present study than for Caja. Whereas Caja only took measurements on one farm operating within the closed system, two housing systems and two productions systems apiece were included in the present paper. The dimensions of the ear-tags studied varied slightly.
The non-significant differences for ear-tag losses and technical-failure rates were explained by the farm effect within the 'ear-tag type' and 'housing- and production system' factors.
Conclusions
The low technical-failure rates for the electronic ear tags allow a large percentage of the pigs delivered to the abattoir to be automatically identified and assigned to their farm of birth. The loss rate for the electronic ear tags proved markedly higher than that of the TVD ear tags, and does not allow for 100% identification of the slaughtered animals. In order to achieve this target, ear-tag losses on the commercial farms in particular must be reduced.
References
Caja, G., Hernández-Jover, M., Conill, C., Garín, D., Alabern, X., Farriol, B. and Ghiradi, J., 2005.
Use of ear tags and injectable transponders for the identification and traceability of pigs from birth to the end of slaughter line. Journal of Animal Science 83: 2215-2224.
Finkenzeller, K., 2002. RFID-Handbuch – Grundlagen und praktische Anwendungen induktiver Funkanlagen, Transponder und kontaktloser Chipkarten. Carl Hanser Verlag, Munich and Vienna.
Published in: Precision livestock farming ’09. Papers presented at the 4th European Conference on Precision Livestock Farming, Wageningen, the Netherlands, 6-8 July 2009
© Wageningen Academic Publishers. The Netherlands, 2009.
