EFFECTS OF INJECTING ELECTRONIC TRANSPONDERS INTO THE AURICLE OF PIGS

Electronic transponders (3 x 18 mm) were injected into the base of the auricle of 69 10-day-old pigs, 111 four-week-old pigs and 24 six-mont h-old pigs, to examine the procedure of injection in the auricle, the tissue reaction and the ease of removal from the carcase. The injectio n was difficult in the 10-day-old pigs, but was easier at four weeks. One of the 204 transponders were lost and five of them appeared to be broken. Only one gilt showed some exudate around the transponder. The transponders could easily be removed when the pigs were slaughtered by cutting off the ear. The position of the transponder was significantl y (P<0.05) more ventral in the animals injected at 10 days old than in those injected at four weeks. The mean thickness of the connective ti ssue capsule around the transponders increased at first (P<0.1) and th en decreased when they were injected into 10-day-old pigs but decrease d (P<0.1) from shortly after injection in the pigs injected at four we eks old. After five months, the capsule in the animals injected at 10 days old was on average significantly (P<0.1) thinner than in those in jected at four weeks.