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ANIMAL PRODUCTION |
* Producció Animal, Departament de Ciència Animal i dels Aliments, Universitat Autónoma de Barcelona, 08193 Bellaterra, Spain;
and
Tracex Trazabilidad en Alimentación SL, 08228 Terrassa, Spain; and
and
Rumitag SL, 08037 Barcelona, Spain
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResults and DiscussionImplicationsLiterature Cited |
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Key Words: Ear Tag • Electronic Identification • Swine • Traceability • Transponder
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResults and DiscussionImplicationsLiterature Cited |
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; Stärk et al., 1998) to reach the 99 (3 mo) and 98% (12 mo) retention rates approved by the International Committee for Animal Recording (ICAR, 2005). The main reasons for this inefficiency are losses, code erasing, short reading distances, transcription errors, negative effects on welfare, and fraud (Caja et al., 2001, 2002).
An effective identification has to be individualized, permanent, simple to apply and read, welfare appropriate, and tamper-proof (Marchant, 1981; Merks and Lambooij, 1990; McKean, 2001). Electronic identification (e-ID) using passive transponders could be an alternative for pigs because it meets most of these requirements (Lambooij and Merks, 1989; Stärk et al., 1998; Caja et al., 2001). The e-ID has been applied for swine management and feeding (Huiskes, 1991; Blair et al., 1994). Electronic devices used in pigs include collars, ear tags and injectable transponders. The auricle base and the ear base are the recommended s.c. injection sites for injectable transponders (Lambooij and Merks, 1989; Lambooij, 1992; Lammers et al., 1995).
Slaughtering conditions for pigs, using fire, hot water, and a high line speed, jeopardize the retention and recovery of the identifiers in the abattoir. Moreover, electronic devices must remain functional at the slaughter line, and removal from the carcass has to be performed in less than 5 s to be considered acceptable (Merks and Lambooij, 1990).
The aim of this experiment was to study the retention rate and functionality of conventional and electronic identification systems in pigs, including injectable transponders in different injection sites and electronic ear tags to evaluate the traceability of pigs from birth to the end of the slaughter line.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResults and DiscussionImplicationsLiterature Cited |
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Piglets were born and reared in an intensive feeding system on a closed-cycle pig farm of the Cooperativa de Artesa de Segre (Lleida, Spain). Farrowing crates (2.9 x 2.0 m) consisted of a farrowing stall for untied sows (2.1 x 0.55 m), with metal slatted flooring and a liquid manure pit. The farrowing barn had a controlled temperature (20 to 28°C). The piglet creep area had plastic covered slats and a heating plate kept at 28°C. Sows were fed a dry diet (2.2 Mcal of NE/kg and 17% CP, as-fed basis) in an automatic trough twice a day. Piglets were provided a creep concentrate ad libitum (3.0 Mcal of NE/kg and 22% CP, as-fed basis). Both the sow and piglets had free access to water through nipple drinkers. Piglets were processed (navel cord and teeth cutting and tail docking), and cross fostering was conducted on the day of birth. An iron injection was applied on d 2. Sows and piglets were checked twice daily for signs of farrowing problems and disadvantaged or dead pigs were removed. Piglets were not castrated, and no relevant health problems were detected.
Piglets were weaned on d 24 ± 3 and mixed into groups of 70 to 90 animals per nursery. Nursery pens (6.5 x 4.0 m) had a concrete slatted floor and a permanently open outdoor dunging zone and two nipple drinkers. Automatic temperature (from 26 to 21°C, decreasing 1°C/wk) and light (from 17 to 9 h/d, decreasing 2 h/wk) controls were used indoors. Pigs were fed ad libitum with a prestarter concentrate (2.7 Mcal of NE/kg and 21.9% CP, as-fed basis) for approximately 12 d and then with a starter concentrate (2.5 Mcal of NE/kg and 19% CP, as-fed basis) for 25 d. Piglets were checked twice daily for signs of discomfort, and disadvantaged or dead pigs were removed.
Finally, the pigs were allocated into single sex groups of 20 to 25 animals per finishing pen (6 x 4 m). The pens had a concrete partially slatted floor, with an automatic feeder and a bowl drinker. Pigs were checked once daily and fed twice daily with a fattening concentrate (2.4 Mcal of NE/kg and 18% CP, as-fed basis) until they reached 7 mo of age with an estimated market weight of 110 kg BW.
Any pig that died during the experiment was sent to the Pathology Service of the Universitat Autònoma de Barcelona for necropsy. Transport to the abattoir was conducted according to European Commission regulations (Directive 95/29/EC). The distance to the abattoir was 35 km, and the journey took approximately 45 min. Pigs were processed in the L’Agudana pig slaughterhouse (Cervera, Lleida, Spain), with electric stunning, bleeding, scalding, dehairing, flaming, evisceration, and carcass processing. The carcasses were immediately chilled in a tunnel (–20°C) and stored in a cold room (4 °C) for approximately 12 h.
Injectable Transponders and Injection Procedures
Five injectable devices (Figure 1) were chosen to compare different injectable transponders (n = 557) from the two radio frequency technologies included in Standard 11785 of the International Standardization Office (ISO, 1996b) and different manufacturers. Full Duplex-B (FDX-B) transponders were Datamars-12 (D12; 12 x 2.12 mm; model T-IS 8010; Datamars, Bedano-Lugano, Switzerland), Sokymat-12 (S12; 12 x 2.12 mm; model Glass Tag; Sokymat, Granges, Switzerland), and Sokymat-34 (S34; 34 x 3.8 mm; model Glass Tag; Sokymat). Half Duplex (HDX) transponders were Tiris-23 (T23; 23 x 3.8 mm; model RI-TRP-RC2B; Rumitag SL, Barcelona, Spain) and Tiris-32 (T32; 32 x 3.8 mm; model RI-TRP-RC2B; Rumitag SL). Serial numbers of injectable transponders agreed with ISO standard 11784 (ISO, 1996a) and included the ICAR manufacturer codes for D12 (Datamars, 981), T23, and T32 (Rumitag SL, 964), and the ICAR test transponder code (999) for S12 and S34. Manufacturer codes are available on the ICAR Website (ICAR, 2004). Transponders were injected into two body sites in piglets: s.c. in the auricle base of the ear and intraperitoneally. Distribution of transponders according to technology, device type, and injection site is shown in Table 1.
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. For the intraperitoneal injection a new technique was used. An assistant placed the piglet on its back and immobilized it with a castration board. The operator then injected the transponder, caudally to the navel, between the fourth and fifth teat of the left side, at approximately 2 cm from the navel and 1 cm from the linnea alba, in an inclined direction toward the abdominal cavity. After the needle traversed the abdominal wall, the injection direction changed to perpendicular and the transponder was released. Injections were performed by five operators, three of them experts in injections in sheep, whereas the other two were trained in a single previous session with five piglets. Each operator injected approximately the same number of transponders in groups of 10.
Transponders were injected by using different injectors according to their size. Single-shot injectors were used for 12-mm narrow transponders. The D12 transponders were applied by using a sterilized disposable needle (25 x 2.5 mm) and syringe set (Datamars). The S12 transponders were applied with an injector (model 3003, Avid, Norco, CA) with interchangeable needles (22 x 2.6 mm) that were immersed in the iodine solution before each injection.
For injection of the T23, T32, and S34 transponders, a multishot injector (model RI-INJ-002 A, Tiris, Texas Instruments, Almelo, The Netherlands) equipped with a multiple-use 50 x 4.8 mm needle (model RI-NDL-002 A, Tiris, Texas Instruments) was used. Transponders were in cartridges of 10 and were covered in an iodine gel (Betadine Oplossing, Dagra, The Netherlands). The needle was immersed in iodine solution before each injection.
Injections in the auricle base with D12 and S12 transponders were done in 1- to 3-wk-old piglets, and S34, T23, and T32 transponders were injected in the auricle base in 2- to 4-wk old piglets. Intraperitoneal injections were done in 1- to 2-wk-old piglets for all transponder sizes. The average injection age according to the injection position and the transponder size is shown in Table 2.
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On-Farm Reading
The PIT were checked before and immediately after injection with a handheld transceiver (Gesreader 2S, Rumitag), and the ear tag number and the complementary data of the animal (dam number, birth date, sex, and observations) were typed and automatically linked to the PIT number. Time required for the injection (time between the identification of two animals) was recorded for both positions. Reading performances were evaluated on d 1, 7, 30, 60, 90, 120, 150, and on the day before slaughtering in static conditions with two different handheld transceivers (Gesreader 2S, Rumitag; and Isomax I, Datamars). The Gesreader 2S was connected to a stick antenna (GasISO, Rumitag). When a PIT could not be read, the animal was immobilized and checked by palpation to determine whether the PIT was lost or broken; otherwise, if the PIT was present and intact, an electronic failure was considered to be the cause.
The e-ID function of the ear tags was checked with the same transceivers, and the identity number was visually identifiable throughout the controls.
Reading and Recovery at Slaughtering
The pigs were slaughtered on different days over a 2-mo period according to BW. The groups were made up of 70 to 100 animals of different treatments. The PIT losses on the slaughter line, the PIT location method for the auricle base position (by sight, palpation, and cutting), and recovery time were recorded.
The slaughter line speed was 200 to 225 animals per hour. Transponders were located with the transceivers. The intraperitoneal PIT were recovered at the slaughter line, when the operator removed the gastrointestinal tract from the animal and placed it in the viscera tray. The PIT in the ear position were recovered before cooling but after the slaughter line, as there was not sufficient time during the process. Transponders were read with the transceiver, and the operator checked its presence visually, by palpation, and finally by cutting the ear. Recovery time was recorded for both injection positions.
After PIT recovery, the carcasses with lost transponders were isolated and checked with a high-sensitivity metal detector (Tiris GM17, Texas Instruments), and the carcass weight was recorded.
Ear tags were recovered at the end of the slaughter line, and the maximum and minimum diameters of the ear hole were measured with a ruler.
Statistical Analyses
To study losses, breakages, and readability of each identification device (on the farm, during transportation, and at the slaughter line), a Logit model with an estimation method of maximum likelihood (Cox, 1970) was chosen due to the dichotomy of the variables. The CATMOD procedure of SAS v. 8.0 (SAS Inst., Inc. Cary, NC) was used, and factors and interactions that were not significant (P > 0.20) were removed from the model. The model used was as follows:
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where p depended on the analysis; pijkl = probability of device losses, breakages, or readability; and µ = overall mean. Variation factors were Di = identification device; Tj = operator training; Sk = sex of the animal; and D x Tij = interaction identification device-operator training.
Results of losses and breakages for intraperitoneally injected transponders could not be analyzed due to the low number of losses throughout the production cycle (one from a total of 309 injected).
Injection time and recovery time were analyzed with the analysis of variance by using the GLM procedure of SAS, and the factors and interactions that were not significant (P > 0.20) were removed from the model. The model included the general mean and the effects of the animal, injectable transponder type, injection position, operator training, sex of the animal, their interactions, and the residual error. Recovery time was transformed into the inverse of the square according to the Box-Cox transformation method (Draper-Smith, 1981), due to the asymmetrical distribution of time. Statistical significance was declared at P < 0.05, and following a significant F-test, means were separated using the Tukey test of SAS.
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Results and Discussion |
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TopAbstractIntroductionMaterials and MethodsResults and DiscussionImplicationsLiterature Cited |
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, 2002), who found no negative effects in cattle or lambs in a similar experiment. According to Whittemore (1993), reference values of mortality for the complete cycle in pig production are less than 15%. In the present experiment, mortality was greater (17.8%), due primarily to an overnight malfunction (10-h duration) of the water supply to a pen of approximately 100 weanling pigs. This occurrence was promptly corrected when discovered the following morning, but resulted in 10.9% mortality for this phase of production.
Injection age differed (P < 0.001) for the auricle base and intraperitoneal position (Table 2). Piglets injected in the auricle base were older (16.7 d) than piglets injected in the intraperitoneal position (12.9 d). There were significant differences (P < 0.05) between transponder sizes in the auricle base position, and older piglets were necessary for large transponders.
Injection time according to injection position and transponder size is shown in Table 3. Time required for transponder injections differed (P < 0.001) between auricle base (101.7 ± 4.7 s) and intraperitoneal position (84.3 ± 3.1 s). For the auricle base injection, time required was greater because piglets were severely restrained to prevent head movement. Times observed to complete auricle base injection in this experiment were greater than the time estimated by Klindtworth et al. (1999) for PIT injection in the ear in cattle (<60 s) and greater than results obtained by Conill et al. (2000) in cattle (44 s) and by Caja et al. (1998) in adult sheep (34 s); there are no previous values for injection time in pigs. A reason for this greater value may be the difference in ear size between species. Injection time required for large transponders was greater (P < 0.05) than for small transponders in both injection sites. There were no differences in injection time between experts (78.4 ± 4.4 s) and inexperienced operators (90.0 ± 3.7 s; P = 0.482). Conill et al. (2000) showed that time required for auricle base injection in cattle was greater for inexperienced than for expert operators. Ear tags were applied without difficulty.
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, who found that 0.6% of pigs had an inflammatory reaction in the injection area 3 wk after injection. No reactions were found after ear tag application either, unlike the results obtained by Huiskes et al. (2000), who reported that 13 to 55% of pigs had a visible irritation of the ear during the first week after application, and the results obtained by Stärk et al. (1998), who found that 18.9% of sows had an adverse reaction to tag application. On-farm losses of transponders in the auricle base position differed according to transponder size. The large size S34 transponders had a greater percentage of losses (72.5%; P < 0.05) than the other transponders. The T32 losses (46.3%) also were greater (P < 0.05) than those of the small transponders (S12 = 19.4%; D12 = 17.1%), which did not differ between them.
Despite the high loss percentage obtained, these results were expected, as it has been demonstrated previously that losses increase with transponder size in swine (Lambooij, 1992; Stärk et al., 1998), as well as in other species (Klindtworth et al., 1999; Lambooij et al., 1999; Conill et al., 2000). The losses of large transponders were greater than those obtained by Lambooij and Merks (1989) with 29-mm transponders in the same position; they reported 35.5% losses. Lambooij et al. (1995) injected 30-mm transponders in the ear base of piglets, a position similar to the auricle base, and obtained a lower percentage of losses (1.6 to 6.9%). Losses of small transponders also were greater than results of other authors, such as Lambooij (1992), who found 10.5% losses with 18-mm transponders, and Stärk et al. (1998), who reported no losses for 11.5-mm transponders, both in the auricle base. Losses of T23 (29.8%) only differed (P < 0.05) from S34, and this percentage also was greater than that obtained by Stärk et al. (1998), who found 19.4% of losses for 23-mm transponders. Conill et al. (2000, 2002) found a lower percentage of losses in cattle (5.2%) and in lambs (4.3%) in the auricle base than the present results. All PIT losses in the auricle base occurred during the first month after injection and the highest percentage of total losses recorded was between d 7 and 30 after injection (40.8%). One possible reason is an inadequate application with insufficient needle penetration, causing the transponder to remain near the application point, facilitating its loss. One loss was found in the intraperitoneal position (0.4%) 1 d after injection. This case was considered to be either a loss or an electronic failure. The first hypothesis could have been a consequence of an inadequate application, introducing the PIT into the digestive system and losing it through the anus. The second hypothesis was discarded at slaughter because the transponder could not be found with the metal detector.
An increase in breakages was anticipated in injectable transponders with increasing transponder size, as Klindtworth et al. (1999) indicated, but this did not occur in our experiment. Mean percentage of PIT breakages in the auricle base was 1.5%, and it did not differ among transponder sizes. Nevertheless, the number of broken transponders was greater than the average obtained by Luini et al. (1996), who reported breakages of 0.3%, and the results of Conill et al. (2000), who reported no breakages, both in the ear in cattle. No breakages were observed in the intraperitoneal position, owing to the fact that in the peritoneal cavity the transponder is protected and enveloped by the abdominal viscera. Electronic failures were only detected in the auricle base (0.5%).
Ear tag losses observed on farm differed among ear tags (C = 1.1%; E1 = 8.8%; E2 = 44.9%), being greater for electronic than control ear tags (P < 0.01). One possible reason for the increased electronic ear tag losses is the greater weight and dimensions of this type of ear tag, as shown by Hasker et al. (1992), Caja et al. (1998), and Klindtworth et al. (1999). These authors found that electronic ear tags presented the same inconveniences as plastic ear tags, as Huiskes (1991) showed in an experiment where different electronic devices, such as collars, ear tags, and injectables, were compared in pigs. The high E2 losses could be associated with an inappropriate plastic used in the manufacture. Similar losses (40 to 60%) were observed in a previous experiment in The Netherlands, with commercial ear tags applied to 3-wk-old piglets, indicating that these ear tags were inadequate (Teer Wee and Aarts, 1991). We observed a relatively low percentage of losses with plastic ear tags, similar to the losses (1.7%) reported by Stärk et al. (1998).
Losses of electronic ear tags in previous experiments were lower than in our experiment. Teixidor et al. (1995) obtained losses between 0 and 0.7% in production conditions similar to the present experiment, and Niggemayer (1994) recorded a total of 5% unreadable electronic ear tags (including losses, electronic failures, and breakages). Stärk et al. (1998) showed no losses with electronic ear tags, and Huiskes et al. (2000) recorded only 0.16% losses before slaughter. Besides losses, electronic ear tags also presented electronic failures (E1 = 5.5%; E2 = 55.1%; P < 0.01) and readability decreased. The percentage of electronic failures obtained with E1 is similar to that reported (5.6%) by Teixidor et al. (1995) using the same ear tags and under the same production conditions.
Readability at the end of the grow-out period varied among devices (Table 4). On average, the auricle base position exhibited a lower (P < 0.001) readability (61.0%) than the intraperitoneal position (99.6%). Moreover, readability differed (P < 0.05) between small (S12 = 80.5%; and D12 = 80.6%) and large (T32 = 51.2%; and S34 = 22.5%) transponders injected in the auricle base; the T23 (70.2%) only differed from S34. The readability reported by Lambooij and Merks (1989) with 29-mm transponders in pigs (57.1%) was relatively low and similar to what we observed. In contrast, Stärk et al. (1998) showed a readability of 80.6% for 23-mm transponders and 100% for 11.5-mm transponders in pigs. Lambooij et al. (1995) reported a readability of 88 to 98% for 30-mm transponders injected in the auricle base in pigs. Conill et al. (2000, 2002) observed a readability of 94.8% in cattle and 95.7% in lambs, respectively.
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). Readability observed for C was similar to that observed by Stärk et al. (1998), who reported a readability of 98.3% for plastic ear tags, but readability reported for electronic ear tags was 100%. Teixidor et al. (1995) obtained a readability of 93.6% during the grow-out period with the same electronic ear tags.
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, in the Dutch Identification and Registration System to control pig transportation in The Netherlands, described the need to have an identification system without losses or reading problems at any stage of pig production, including transportation.
The readability and recovery of the injectable transponders at the slaughter line are shown in Table 6. Losses and breakages of auricle base transponders at the slaughter line were similar among transponder sizes (D12 = 6.8%; S12 = 12.2%; and S34 = 22.2%) and were probably due to carcass processing, such as flaming and dehairing. Similar problems were reported by Lambooij and Merks (1989) at the slaughter line, with a high percentage of losses (12.5%) and breakages (62.5%). Despite this, Lambooij (1992) observed no losses with 18-mm transponders in the auricle position at the slaughter line. Similarly, Lammers et al. (1995) reported zero losses of auricle-injected transponders, but some transponders (1.8 to 20%) could not be recovered from the carcass after cutting the auricular canal. Stärk et al. (1998) observed low breakages (1.2%) with 23-mm transponders and no breakages with 11.5-mm transponders.
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reported a loss and failure rate of 5.4 and 21.6%, respectively, for electronic ear tags. Stärk et al. (1998) observed a loss rate at the slaughter line of 3.6% for plastic and 10.4% for electronic ear tags. They also observed 10.4% electronic failures. Recently, Huiskes et al. (2000) reported a loss and failure rate of 1.8 to 4% and 0 to 1.9%, respectively, at the slaughter line, which was attributed to the rubber fingers of the dehairing machine.
Auricle base transponders were recovered after carcass processing because of time limitations on the slaughter line. Total recovery of auricle base transponders was 96.8% (Table 6). Recovery values in the literature show great variability. Lambooij and Merks (1989) only recovered 11.8% of transponders after the slaughter line. In contrast, Lambooij (1992) and Stärk et al. (1998) reported 100% recovery in the same injection position. For this position, three recovery procedures, sight, palpation, and cut, were used. Values for each procedure were 30.2, 27.4, and 42.5% respectively. No intraperitoneal transponders were lost before evisceration, and the identification could be transferred to the carcass before opening the abdominal cavity; however, a successful recovery system of intraperitoneal transponders has not been developed. Moreover, some of the transponders (18.6%) fell out at the moment of evisceration. No intraperitoneal injectable transponders were found in the carcasses and transponder injection caused no damage or alteration to the carcasses. Transponders were always found loose in the peritoneal cavity, without any viscera adhesion. Recovery times shown in Table 6 did not differ (P = 0.13) between injection positions, but they differed among transponder sizes (P < 0.05) in the auricle base position. There are no previous results of recovery time for pigs. Percentages of transponders recovered in less than 10 s were 61.4 and 42.3% for intraperitoneal and auricle base position (P < 0.01), respectively (Figure 2). This percentage increased to 77.3 and 64.4% in less than 20 s for intraperitoneal and auricle base positions, respectively, and for under 60 s, values reached 92.1 and 92.5%, respectively, but differences were not significant. Recovery times exceeded the recommendations for pigs (less than 5 s; Merks and Lambooij, 1990).
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). For lambs, time recorded for transponders injected in the armpit and retroauricular position was greater than 10 s (Conill et al., 2002). The slaughter line speed for swine is usually between 350 and 400 animals per hour, so recovery time should be less than 10 s to maintain the work speed.
The traceability of all identification devices from farm to evisceration is presented in Table 7. Best results were achieved for the intraperitoneal location (99.6%). Stärk et al. (1998) achieved a 100% success rate, but 11.5-mm transponders injected in the auricle base were used in that study. Traceability obtained with PIT in the auricle base averaged 57.1% and differed (P < 0.05) among transponder sizes (D12 = 75%; S12 = 70.7%; T23 = 70.2%; T32 = 51.2%; and S34 = 17.5%). Lambooij (1992) recorded traceability values of 89.5 and 100% with 18-mm transponders, and Lammers et al. (1995) obtained 91.7% traceability with the same type of transponders. Stärk et al. (1998), found 76.1 and 100% traceability with 23-and 11.5-mm transponders, respectively, in the auricle base position. The only experiment in which very low results of traceability were reported with large transponders in the auricle base, was the study carried out by Lambooij and Merks (1989), who reported 11.8% final readability. Traceability of ear tags was different (P < 0.05) between control (86.7%) and E1 (68.1%); E2 traceability was 0%. These results were lower than those obtained by Stärk et al. (1998), who reported a readability of 96.4 and 76.6% for plastic and electronic ear tags, respectively, and were lower than results obtained by Huiskes et al. (2000), who reported traceability to be between 94.0 and 97.8%. Teixidor et al. (1995), however, obtained a percentage of traceability (67%) similar to our results with electronic ear tags.
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TopAbstractIntroductionMaterials and MethodsResults and DiscussionImplicationsLiterature Cited |
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Footnotes |
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2 The authors appreciate the assistance of the crew of La Industrial pig farm of the Cooperativa de Artesa de Segre (Artesa de Segre, Lleida, Spain) for feeding and taking care of the animals; the Direction and Veterinary teams of the slaughterhouse of L‘Agudana (Cervera, Lleida, Spain) for the slaughtering and transponder recovery facilities; M. Emmenegger of Datamars (Bedano-Lugano, Switzerland), J. Francesc Vilaseca of Rumitag (Barcelona, Spain), and M. Villamayor of Sokymat (Granges, Switzerland) for the supply of the transponders; and N. Aldam for the English revision of the manuscript.
4 Current address: Facultad de Veterinaria, Universidad de la República, Av. Lasplaces 1550, 12500 Montevideo, Uruguay.
3 Correspondence—fax: +34 93 581 1494; e-mail: gerardo.caja{at}uab.es.
Received for publication September 29, 2004. Accepted for publication May 26, 2005.
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