A comparison of commonly used ear tags on the ear damage of sheep

The damage caused by ear tags used for sheep identification was investigated in a two-part study. In Part I, ear tags classified as metal loop, golf-tee, single flex or lambtag were inserted into the ears of 62 ewes. The severity of ewe ear lesions was monitored until 20 weeks after ear tag insertion. In Part II, 351 lambs had tags classified as metal loop, plastic loop, golf-tee, double flex, single flap, lambtag and electronic, inserted in their ears. The behaviour of the lambs was observed for 30s after insertion of the ear tag. The severity of lamb ear lesions was monitored until 5 weeks after ear tag insertion. In both ewes and lambs there was a significantly greater risk of severe and persistent ear lesions following the use of metal loop tags as compared with the other types of ear tag (P <0.001). The single flap tag was difficult to insert in a greater proportion of lambs (P <0.001), and more lambs haemorrhaged (P <0.001), vocalized (P = 0.002) and shook their heads (P = 0.004) with it, than with the other types of ear tags. All ear tags resulted in an inflammatory reaction and required correct positioning to minimize the severity of ear lesions.