Injectable Transponders Research Articles

The feasibility of using passive injectable transponders in field operations for individual identification of sheep in Italy

This trial evaluates the feasibility of using passive injectable transponders (PITs) in field operations by testing identification procedures on 185 one-year-old Biellese ewes reared under nomadic farming conditions. Commercial PITs of 3.85 ± 0.05 mm × 31.2 mm were used at two application sites, the armpit and the retro-auricular region. The two application sites were compared taking into account the ease of injection, animal reaction, injection duration, inflammatory response, PIT readability at up to 12 months post-injection and PIT recovery at the slaughterhouse. The injection site influenced the reaction of the animal and the ease and duration of the injection, but it did not affect the palpation and the reading findings during the rearing period. The injection site also influenced the PIT retrieval at the slaughterhouse depending on the operator who recovered the PIT. The readability values observed at the end of the observation period for both injection sites (83% in the retro-auricular region and 79% in the armpit region) were too low to be suitable for long-term animal identification. In addition, the failed retrieval of PITs at slaughter, determined the destruction of 40 (22%) carcases to avoid any risks in the food chain. These findings suggest that the limited use of PITs is indicated when other methods of electronic identification cannot be employed, while a wider application of the device tested in the present study is not recommended in farming practices.

State-of-the-art of electronic identification techniques and applications in goats

Use of electronic identification (e-ID) of caprine breeding stock, based on radio frequency passive transponders, is compulsory in most EU countries and it is foreseen as a powerful tool for the improvement of the goat industry. This paper compares the performances of the most used e-ID devices (i.e., ear tags, injects, boluses and leg tags) with plastic ear tags in goats. Ear dimensions, environment and ear tag features result in variable retention and readability of visual and e-ID ear tags in goats. Light and high quality button ear tags provide suitable results under intensive conditions but they are not fully satisfactory under extensive conditions. Injectable transponders have been also evaluated in different body sites (ear base, armpit, groin, tail, pastern and intraperitoneal) of goats. Main drawbacks of injects are migration and retrieval at slaughter, but injection in the armpit is suitable for goats under harsh conditions (i.e., game and feral goats) and carcass traceability. Injection in the pastern has the advantage of not letting carcass residues, although readability is compromised by the small size of the transponders used and is not recommended for most on-farm applications. Performances of e-ID rumen boluses vary by bolus features and goat breed. Research showed that denser boluses than in sheep (>3.3) and high quality transponders allow >98% readability in goats. Leg tags are only recommended for adult dairy goats under intensive conditions. Dynamic reading efficiency strongly depends on the position of the antenna and on the type of e-ID device, which becomes an issue of major relevance when different e-ID device types are in use in the same herd for management and performance recording.

Long-Time Evaluation of Biological Effects of Transponders Implanted Subcutaneously in the Midway Region of the Left Neck in Four Goats

Long-Time Evaluation of Biological Effects of Transponders Implanted Subcutaneously in the Midway Region of the Left Neck in Four Goats Electronic identification of livestock animals is currently a major topic within the food producing industry. Contrary to small ruminants, cattle and pig, passive injectable transponders are recommended as a secure method of pets and horse identification but evaluations about the long-time biological effects of transponders are generally lacking.

Recognised-by-law versus other identification systems in pigs: piglets discomfort evaluation and performance testing

The aim of the study was to evaluate the performance of recognised by Italian law (tattoos) and other (ear tags and injectable transponders) identification systems and to investigate if they caused different levels of short-term discomfort in piglets. Ninety-six ten-day-old piglets — equally assigned to four experimental groups — were identified with electronic ear tags (EET), transponders injected in the auricle base (TAB), in intraperitoneal position (TIP), or ear tattoo (T). Losses, breakages and readability of the identification devices were recorded to evaluate their efficiency. Fortyeight piglets were observed continuously for 5 min after identification. Behavioural indicators of pain, discomfort or ease were recorded in terms of duration of occurrence or frequency. Non-parametric analyses of variance were used to compare time required for the application of the devices and behavioural reactions of piglets. No healing problems or breakages of the electronic devices were observed during the trial. The readability after nine months was 93.8% for EET and TIP, 86.7% for TAB and 0% for T. The time required for the application differed significantly (P<0.001) among the four identification devices. EET and TIP showed better results than T considering losses, breakages, readability and time required for application. Behaviours most frequently recorded were head shaking and ear scratching, observed more frequently in piglets after the application of EET (P<0.001). The application of these identification devices caused a mild discomfort in piglets; further studies should investigate in detail the intensity and duration of reactions to the identification procedure.

Subcutaneous electronic identification in cattle: a field study

The use of injectable transponders in cattle for identification purposes, for up to 30 months, was investigated. Passive electronic transponders, encapsulated in either polymer or glass, were injected subcutaneously into...

Assessment of acute pain experienced by piglets from ear tagging, ear notching and intraperitoneal injectable transponders

Suckling piglets are routinely identified to assist with their day-to-day management. A total of 120 suckling piglets were used to determine and compare the short-term pain responses to a number of identification methodologies, including: ear notching, ear tagging and intraperitoneal injection (IP) of a 4 mm × 32 mm glass encapsulated transponder. Two additional groups of piglets were used as controls for the different handling positions (ear or IP treatments). Treatments were applied to suckling piglets during a 90-s period and the pain response was determined using behavioural observations, vocalisation recordings, physiological measurements and growth performance analysis. Saliva samples for cortisol analysis were collected 15 min pre- and post-treatment from all animals, and blood samples for lactate analysis were collected at the time of treatment application and after 10 min from the ear notched and IP injected groups. Piglet behaviour was observed in the farrowing crate using instantaneous scan sampling with recordings made at 5-min intervals over a 3 h period. Pain-related behavioural displays were found to be significantly higher ( P < 0.01) in ear notched and ear tagged animals than in other groups. Piglets in the treatment groups displayed an increase in awake inactive behaviours relative to controls. Longer time periods of isolation were observed in ear tagged and IP injected piglets than those in other treatment groups ( P < 0.05). Ear tagged, IP injected and SHAMIP animals showed higher sound pressure levels at the beginning of the treatment (first 30 s) in comparison to the end of the recording interval ( P < 0.05). There was a tendency ( P = 0.059) toward vocalisation differences across treatment groups, with the highest sound pressure among ear notched pigs (54.57 ± 1.76 dBA). Lactate levels increased ( P < 0.05) due to treatment in ear notched animals, with similar values pre and post-treatment for both ear notched and IP injected animals. Cortisol concentrations increased ( P < 0.05) after treatment but no differences between groups were observed. These results suggest that identification practices of suckling piglets induce acute pain responses, these being more significant between ear tagged and ear notched animals. However, the non-specific behavioural displays of IP injected piglets could be an indication of acute pain. The use of short-term analgesia may be warranted to reduce acute pain when identifying suckling piglets.

Technical note: electronic identification of live rabbits ,preliminary study to identify a body injection site

Identification and monitoring of farm animals are effective tools for traceability. Current livestock identification systems are not 100% efficient and present certain disadvantages such as losses, breakages and an unreadable identification code. The use of injectable transponders may be a reliable method for individual identification, providing an improvement in data recording and farm management. The aim of this experiment was to evaluate the practical aspects concerning injection technique, readability and retrieval of injectable transponders in live rabbits. A total of 60 rabbits (40 fatteners and 20 does) were injected with 23x3mm passive FDX-B transponders (Datamars, Switzerland), inserted into a needle, wrapped in a sterilised package and applied by a specific injector (Planet ID, Germany). Two different body sites were evaluated: back scapular (n=30) and armpit (n=30) position. The readings of the transponders were performed by using an i-max plus portable reader (Datamars, Switzerland) at different times: before and after injection, one day, one week and one month after injection. Does were read monthly during 1 year, while fatteners before the slaughtering process. To evaluate the effect on productive performance, fattening rabbits were compared to a control group. The readability of transponders injected in fatteners until slaughter and in does until 1 year after injection was 100%. No harmful effects were observed and no significant difference in weight was found in the two injection groups, compared with the control group. The retrieval was performed by a single operator at skinning, with 100% of transponders recovered. The site of the injection did not affect the migration rate, although it was high in both cases. The feasibility of subcutaneous transponder injection in live rabbits is recommended in the two body positions analysed. However, specific training and operator experience are necessary to improve the efficiency of this identification system.

Study on injectable transponders with temperature sensor at bull-calves.

The following paper describes a fi eld test carried out in 2008 to compare square planting and normal sowing with silo maize under special consideration of the effect on yield, weed regularisation, as well as work economy and profitability. So cross compound should be examined in the investigation as a new cultivation technology. The cross compound particularly stand out due to its sowing in a square compound of 33 by 33 cm. On this occasion, the single sowing rows connect precisely with each other. This idea to create cross compounds makes it possible to hoe in two different directions: in the machine direction and also in a cross direction and consequently the weed free space is raised from about 66 % up to 90 %.

Use of Injectable Transponders for the Identification and Traceability of Pigs

Individual identification in pigs is a key point for management, traceability and trade control. The aim of this experiment was to study retention rate and functionality of electronic identification systems in pigs, injected in different sites, evaluate traceability of animals and highlight histopathological alterations of tissues in different inoculation sites.A total of 60 crossbred piglets were used to compare different transponder inoculation sites. One group (15 piglets) was identified only by plastic ear-tags, while three groups were identified by passive injectable transponders (PIT), with different inoculation sites. Pigs were slaughtered in two different moments, in order to evaluate injection sites, macroscopically and histologically, either 50 days after injection or at a normal slaughtering weight. In general, no apparent animal health problems were observed the day after the injection or during the control readings performed during the experiment. Intraperitoneal localization gave excellent results in term of readability until the slaughter time. Transponders at the slaughter line were always recovered in the viscera tray, as they were found loose in the peritoneal cavity. In some cases, they were found on the carcasses, attached to the peritoneum. In those cases a sample of peritoneal tissue was collected for histological examination. A reparative chronic reaction with moderate and multifocal fibrosis and neoformed vessels associated to multifocal and mild lymphoplasmacytic infiltrate were detected. In one case (6.7%) the transponder was found on the visceral side of the liver and the histological examination highlighted a localized superficial hepatic atrophy by compression.Retroauricolar site of injection gave lower readability results, as 2 transponders (13.3%) were no more readable during the first month after injection. No lesions were found with this inoculation site.PIT injected in the perineal region were operative until slaughter time. Recovery procedures at the slaughterhouse were simple for animals slaughtered at a low weight, but much more difficult in the case of heavy pigs. Moreover, in three cases (20%), PITs were no more in the subcutaneous tissue but had an intramuscular localization. The histological examination of the muscles revealed a chronic reparative process.In our experiment, injectable transponders in the intraperitoneal position provided the best identification system for pigs. Histo -pathological examination revealed only local reparative processes in the tissues interested by PIT contact, and no other pathological changes.

REVIEW: Identification and Traceability of Cattle in Selected Countries Outside of North America

<h2>ABSTRACT</h2> Animal identification by means of marking animals' bodies was first recorded 3,800yr ago in the Code of Hammurabi, and throughout history, valuable animals such as horses have been identified to prevent thievery all over the world. Today, the reasons for identification of livestock include production management, control of disease outbreaks, establishment of ownership, requirements for export, and consumer demands. Additionally, there are many methods of animal identification and traceability available today including ear tags, tattooing, branding, electronic methods that implement radio frequency identification technologies (such as rumen boluses, ear tags, and injectable transponders), and biometric methods (such as retinal scanning, nose prints, and DNA). The objective of this review is to demonstrate the implementation of bovine animal identification and traceability systems in selected countries outside of North America (i.e., United States, Canada, and Mexico) for the purpose of creating a knowledge base whereby an effective North American bovine animal identification and traceability system may be created and implemented. This review will discuss regulatory requirements of animal identification and traceability in selected countries.

Traceability of extensively produced Iberian pigs using visual and electronic identification devices from farm to slaughter1

A total of 351 Iberian pigs with equal numbers of both sexes from 2 commercial farms were used to study the ability of various identification devices to guarantee the traceability required for labeled meat products from Iberian pigs reared under extensive production conditions in Spain. The performance of tattoos, visual ear tags, electronic ear tags, and i.p.-injected transponders of half duplex and full duplex technologies were compared during a production cycle from nursery to slaughter at 15 mo of age (156 +/- 3 kg of BW). No major health reactions to any of the identification methods were detected. Results showed that tattooing was not an adequate identification procedure due to reading difficulties as a consequence of dark skin, soiled appearance, and figure deformation. Ear tag losses and failures were affected by fencing type and increased in one of the farms (20.4 and 15.7% for losses and failures, respectively; P < 0.05) as a consequence of using barbed-wire fences. Ear tag losses decreased when fences changed to stone blocks at 365 d of age. Visual and electronic ear tag losses during transport and slaughter were low (3.7% for visual and 3.1% for electronic tag). Results of injectable transponders during the growing-fattening period were variable and were more readable for the half duplex than for the full duplex i.p. transponders (92.0 vs. 68.7% +/- 1.5; P < 0.05). Handheld transceivers worked properly under extensive conditions, although the body size and skin characteristics of the Iberian breed might limit the performance of reading devices, and the use of transceivers with longer reading distances is recommended. The main problem observed with i.p. transponders was their low recovery rate at slaughter due to the lack of adherence of the transponders to the omentum.

Estimativa do padrão de preferência térmica de matrizes pesadas (frango de corte)

A produtividade de matrizes pesadas (frango de corte) está ligada aos princípios de conforto térmico, diretamente relacionados ao microclima da instalação. Neste trabalho objetivou-se o monitoramento do comportamento de matrizes pesadas usando-se a tecnologia de radiofreqüência, identificadores eletrônicos injetáveis e leitores no interior de modelo de galpão de produção em escala reduzida e distorcida. Utilizaram-se no experimento oito aves com identificação eletrônica. Três antenas foram dispostas em três pontos dentro do modelo: no piso do ninho, na passagem entre a parede lateral e o comedouro e sob o bebedouro. Registraram-se continuamente as temperaturas de bulbo seco (TBS), bulbo úmido (TBU) e de globo negro (TGN). Os resultados apontam para um padrão de preferência térmica das aves diferenciado frente às situações de ambiente ocorridas no experimento. Três modelos probabilísticos de comportamento foram desenvolvidos a partir dos registros coletados: modelo probabilístico para uso da passagem: FP = 1,10 - 0,244 ln(TBS), modelo probabilístico para uso do bebedouro: FB = 0,398 + 0,00866 tbs, e modelo probabilístico para uso do ninho: FN = 2,22 - 0,272 TBS + 0,011 TBS² - 0,000144 TBS³.

Comparison of visual and electronic identification devices in pigs: On-farm performances1,2

A total of 1,822 pigs from 2 farms (farm A, n = 1,032; farm B, n = 790) were used to evaluate pig traceability under on-farm conditions by using identification devices (n = 4,434) of different technologies. The devices were visual ear tags (n = 1,533; Model 1, n = 776; Model 2, n = 757), electronic ear tags (n = 1,446; half-duplex, n = 702; full-duplex, n = 744), and intraperitoneally injected transponders (n = 1,455; half-duplex, n = 732; full-duplex, n = 723). A group of 790 pigs wore 3 types of devices, and 1,032 wore 2 devices. Piglets were identified before (wk 1 to 3 of age; farm A) or after (wk 3 to 4 of age; farm B) weaning and intensively fattened until approximately 100 kg of BW. Readability of devices was checked at each farm operation by using standardized handheld transceivers. No negative effects of the identification devices on animal health (mortality rate, 8.4%) or performance were detected. On-farm losses averaged 1.6% for ear tags (visual, 0.8%; half-duplex, 1.9%; full-duplex, 2.7%; P > 0.05) and 1.8% for intraperitoneally injected transponders (half-duplex, 1.7%; full-duplex, 1.9%; P > 0.05). Moreover, 1.4% electronic failures occurred in the electronic ear tags (half-duplex, 2.2%; full-duplex, 0.6%; P < 0.05) but not in the intraperitoneally injected transponders. Final on-farm readability was greater (P < 0.05) for visual ear tags (99.2%) than for electronic ear tags (half-duplex, 95.9%; full-duplex, 96.7%; P > 0.05). Readability for intraperitoneally injected transponders was intermediate (half-duplex, 98.3%; full-duplex, 98.1%; P > 0.05). Electronic devices were in all cases easier and faster to read than the visual ear tags. Visual ear tags and intraperitoneally injected transponders were efficiently retained under conditions of commercial pig farms, which agrees with the minimum values recommended by the International Committee for Animal Recording (> 98%). When readability and reading ease were also included as decision criteria, injectable transponders were preferred.

Use of ear tags and injectable transponders for the identification and traceability of pigs from birth to the end of the slaughter line1,2

A total of 557 newborn piglets were used to compare eight identification devices, including one plastic ear tag as a control (C, n = 348) and two types of electronic ear tags (E1, n = 106; and E2, n = 103), and five types of injectable transponders (n = 557): small 12-mm (D12, n = 116; and S12, n = 110), medium 23-mm (T23, n = 108), and large (32-mm, T32, n = 115; and 34-mm, S34, n = 108). Injections were made s.c. in the auricle base (n = 248) and intraperitoneally (n = 309) using a new technique. All piglets were identified with two devices, but using electronic ear tags in conjunction with injection in the auricle was avoided on the same pig. Readability of devices was checked during fattening (until 110 kg BW) and slaughtering. On-farm losses were lower for control than for electronic ear tags (C = 1.1%; E1 = 8.8%; and E2 = 44.9%; P < 0.01); the latter also suffered electronic failures (E1 = 5.5%; and E2 = 55.1%; P < 0.001). On-farm losses of transponders injected in the auricle base were greater in large (S34 = 72.5%; and T32 = 46.3%; P < 0.05) than in small transponders (S12 = 19.4%; and D12 = 17.1%), but T23 (29.8%) only differed from S34. Transponder size did not affect on-farm losses for intraperitoneal injections in which only one loss was recorded (0.4%). All ear tags had similar losses during transportation to the slaughterhouse (1.2%), but no losses were observed in injectables. Slaughtering losses did not differ between ear tags (C = 11.2%; and E1 = 6.4%), but apart from losses, 12.8% of E1 failed electronically. Injection site affected losses and breakages during slaughtering (auricle base = 6.4%; and intraperitoneal = 0%), but recovery time did not significantly differ (auricle base = 28.6 s; and intraperitoneal = 18.9 s). Transponders in the auricle base were recovered by sight (30.2%), palpation (27.4%), or by cutting (42.5%). Intraperitoneal transponders were mainly recovered loose in the abdominal cavity (81.4%), whereas 18.6% fell on the floor. As a result, traceability varied significantly (P < 0.05) between control (86.7%) and electronic ear tags (0 to 68.1%) and injectable transponders, with the auricle base (17.8 to 75.0%) having lower values than intraperitoneal (98 to 100%). Intraperitoneal injection was a very effective tool for piglet identification and traceability, ensuring the transfer of information from farm to slaughterhouse. To warrant the use of this technique in practice, transponder recovery requires further investigation.

Locais de implante de microchips de identificação eletrônica de leitões: seleção e validação por análise de imagem

Nas últimas décadas, a produção de suínos, pressionada por uma crescente demanda por alimentos, tem-se caracterizado pela maior concentração de animais em grandes unidades de produção, dificultando o registro dos dados individuais. Os sistemas automáticos de identificação eletrônica podem auxiliar a detecção de doenças, a avaliação de respostas fisiológicas, o controle de ingestão de alimentos, a atividade física e ainda o impacto ambiental causado pelo sistema de produção, promovendo melhor controle da propriedade. Transponders injetáveis, brincos eletrônicos e o monitoramento por meio da análise de imagem estão sendo utilizados no processo de identificação. O objetivo desta pesquisa foi avaliar os diferentes locais de implante subcutâneo de microchips em leitões, verificando-se possíveis infecções e/ou rejeições, migrações dos microchips em relação ao local de implante e sua validação em relação à análise de imagem.

Electronic identification in rabbits: two body sites of injectable transponder

Identification and monitoring of farm animals are effective tools for traceability. Actual livestock identification systems (ear-tags, tattoos, etc.) are not completely efficient and offer some inconveniences. The use of injectable transponders might be a reliable method for individual identification, allowing the improvement of the data recording and the farm management. The aim of this experiment was to evaluate the applicability of injectable transponder in live rabbits. A total of 40 fattening rabbits of 55 days old were injected with 23 mm passive FDX-B transponders (Datamars, Switzerland), preloaded into a needle in a sterilised packaged and applied by using a transponder injector (Planet ID, Germany). Two body locations for transponder’s injection were studied: laterally to the neck (n=20) and armpit (n=20). Readings of the transponders were performed using portable ISO transceiver, before injection, after injection, the day after, after one week, after one month, before the slaughtering process. Rabbits were weighted at the injection, one week and one month after injection, and at slaughtering; a control group of not treated animals were weight to compare the effect of manipulation. Growth performance were studied by analysis of variance, using of GLM procedure. A χ2 test was used to analyse difference in migration rate. Readability of transponders in the fatteners until slaughterhouse was 100%. Recovery of transponder during the slaughtering process was easy with 100% of transponders recovered. Body site of injection didn’t affect the migration rate, nevertheless it was low. In one animal, the transponder was recovered into the scapular muscle. No harmful effects of the transponder injection on the animals were observed. Weight difference of animals was not significant for the two body site of injection, compare to the control group. Preliminary results showed that transponders can be used as a method for traceability and monitoring of live rabbits, allowing the improvement of the management of a farm.

The use of passive injectable transponders in fattening lambs from birth to slaughter: effects of injection position, age, and breed.

A total of 1,159 Tiris half-duplex passive injectable transponders (PIT) of 32-mm length were used to study the electronic identification of 618 fattening lambs of two breeds used for different production purposes (Ripollesa, meat breed, n = 271, and Manchega, dairy breed, n = 347). The lambs were s.c. injected in the armpit and the retro-auricular positions at 2, 15, and 30 d of age. All lambs were also tagged with a small plastic ear tag after birth. A group of 76 lambs were injected only in the right armpit and were kept for breeding. The PIT losses, breakages, and electronic failures were evaluated at weekly weight recordings throughout the fattening period using two types of hand-held transceivers. Fattened lambs were harvested in a commercial abattoir between 3 and 4 mo of age when they reached market weight (11 to 12 kg hot carcass weight). The total number of PIT that fell or broke in the slaughtering line, the location method, and the recovery time were recorded. On the farm PIT losses were not affected (P > 0.05) by age at injection, injection position, or breed. Mean losses of PIT and ear tags during the same period were 5% and 6.3%, respectively (P > 0.05). No PIT breakages or failures were observed during the fattening period. Mean recovery of PIT in the abattoir (85.6%) was affected (P < 0.05) by breed and injection position. Losses of PIT in the abattoir were greater (P < 0.05) in the Ripollesa breed (18.4%) than in Manchega (10.0%), and for both breeds losses were greater (P < 0.05) in the retro-auricular than in the armpit positions (18.6 vs 10.8%, respectively). The percentage of PIT broken during slaughtering was low (0.3%). The mean recovery times (18 +/- 2 s) were not affected (P > 0.05) by breed, injection position, or age, thus allowing a harvesting speed of 200 lambs/h on average. In conclusion, the injection of 32-mm PIT into the armpit or the retro-auricular region is not recommended as a practice for the electronic identification of fattening lambs, even though they perform similarly to small plastic ear tags. This is partly a consequence of the PIT losses observed on the farm but mainly because of the difficulties with recovering the PIT in the abattoir. More research will determine whether the use of smaller transponders or injection in other positions could improve their performance in fattening lambs.

Effects of injection position and transponder size on the performances of passive injectable transponders used for the electronic identification of cattle.

A total of 686 Tiris half-duplex passive injectable transponders (PIT) of two sizes (23 and 32 mm) were randomly injected s.c. in three positions, armpit, ear scutulum, and upper lip, in 343 fattening calves (1 to 3 mo old). Injections were performed by two trained and two untrained operators. Losses and breakages on the farm were recorded at wk 1, 3, 7, 11, and 15 in restrained animals using two types of hand-held transceivers with a stick antenna. Dynamic reading efficiency (DRE) in animals running through a raceway was also evaluated at wk 1 and 3 and monthly until slaughter, using a stationary transceiver working at 137 dB x microV x m(-1) at 3 m. The total number of PIT that fell or broke in the slaughtering line, the location method, and the recovery time were also recorded. Results on the farm showed low breakages on average (0.4%) and differences (P < 0.05) in losses according to position (armpit, 1.7%; ear, 5.2%; and lip, 14.0%). An interaction (P < 0.05) between position x size was observed, and losses were greatest using a 32-mm PIT in the lip. The DRE was affected (P < 0.05) by PIT position and size, and values were greater for the 32-mm PIT in all positions (armpit: 99.9 +/- 0.1 vs 95.8 +/- 4.9%; ear: 93.8 +/- 2.2 vs 81.9 +/- 4.6%; lip: 66.8 +/- 4.9 vs 53.4 +/- 4.7%, respectively, for 32 vs 23 mm). Recovery of PIT in the abattoir was on average 96.7, 96.7, and 99.2% for armpit, ear, and lip, respectively (P > 0.05). Most of the PIT injected in the armpit were recovered by sight or palpation, but 31.9% were recovered after cutting the muscles around the area and 10.7% were recovered on the internal side of the hide, which jeopardized carcass identification. Recovery of PIT injected in the ear was 23.4% in the hide and 76.6% in the auricular muscles of the head. The easiest recovery was in the lip, 8.9% of PIT were located in the hide and 91.1% in the head. Recovery time was affected (P < 0.05) by position: the quickest was lip (27 +/- 2 s), followed by ear (52 +/- 5 s) and armpit (78 +/- 7 s). In conclusion, taking into account retention and reading performances, injection of a 32-mm PIT into the armpit showed the best results on the farm, but a careful and longer recovery was needed in the abattoir. Improvement of recovery methodology and time would be necessary in order to recommend injection of PIT in the armpit instead of in the ear for cattle tracking or monitoring.

Electronic identification of cattle with injectable transponders

Electronic identification with injectable transponders is a promising way to improve the present system of animal tagging. The application inside the body of animals reduces the risk of loss, eventually manipulations and fraud to a minimum. On the other hand the injected transponder has to fulfil important requirements for its use in practice. Main aspects are the biological compatibility, feasibility of injection, technical performance under static and dynamic conditions and finally the procedure of recovery in commercial slaughterlines to avoid any risk for the human food chain. The article gives a review about research activities of the last years, which were carried out with different types of transponders, using the injection spot scutulum in cattle.

Animal identification: introduction and history

In the beginning of the 1970 research institutes in different countries developed the first electronic animal identification systems. These systems were tested on experimental farms. The first systems were all built with the conventional components and attached to a collar around the cow’s neck. In the 1980s however special integrated circuits were developed minimising the size of the transponders. Now in the 1990s, official organisations are testing systems for identification and registration of all animals to control movements from birth to slaughterhouse. This will enable farm livestock to be traced at the outbreak of diseases and residues in slaughter animals to be followed up. Injectable transponders, electronic eartags and rumenal bolusses are being used.