Use of injectable transponders for the identification and traceability of pigs

Abstract

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, to 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; and 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 because 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 because 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 slaughter house 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 they 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. Histopathological examination revealed only local reparative processes in the tissues interested by PIT contact, and no other pathological changes

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

“…The application of the ear tag is a rather simple operation and can be done by the farmer without risks for the animal. In literature, Stärk et al (1998) and, recently, Prola et al (2010) reported a readability of 100% for electronic ear tags in pigs; in contrast, Babot et al (2006) obtained a similar readability (96.7%) to the one observed in our trial. The reading shows a percentage of error of 0.1%, however, problems may rise as ear tags are subject to a high loss rate, up to 40% (Caja et al, 2004).…”

“…Different performances could be explained by technical characteristics of ear tags (weight, shape, materials, etc.) that influBarbieri et al (Lambooij and Merks, 1989;Stärk et al, 1998) obtained a lower readability, while Prola et al (2010) reported the same percentage, as summarized in Table 3. One of the most important parameters for evaluating the suitability of an identification system for field use is the time needed for its application.…”

“…Very few problems have been reported regarding the injection of the transponder in the auricle base and intraperitoneally. Nonetheless, some authors underline the possibility of an inflammatory reaction after the injection and a chronic reparative process, without alteration of the long-term production parameters or animal health (Lambooij, 1992;Lammers et al, 1995;Prola et al, 2010). In our trial, no healing problems (infection or necrosis) were observed.…”

Individual identification of pigs during rearing and at slaughter using microchips

“…In this study, a large number of microchips were lost from the auricle base during the first month after injection, confirming previous findings (Caja et al, 2005;Prola et al, 2010). A possible reason for this unacceptably large loss of microchips could be the size of the needle used for injection, which could have allowed the microchip to fall out before the skin had healed (Caja et al, 2005).…”

Possibilities of establishing a smallholder pig identification and traceability system in Kenya

“…A transponder that is deposited close to the point of application is likely to be lost after application (Caja et al 2005). Perineal transponders are difficult to recover in heavy pigs, and incisions to remove them at slaughter could compromise carcass quality (Prola et al 2010). Intra-peritoneal application is perceived to be easy to apply (Marchi et al 2007); Caja et al (2005) found transponder application at the intra-peritoneal location (took 84.3 s) to take less time than that done at the auricle base which was more time consuming (101.7 s).…”