Welfare implications of identification of cattle by ear tags.
The damage caused by ear tags used for identification was studied by examining the ears of normal beef cattle and cull cows after slaughter, and by comparing the effects of metal and polyurethane ear tags in calves which had been double-tagged in the same ear. Metal tags were associated with more damage to the ears than polyurethane tags, the difference being most marked in the young calves, in which slight changes were found in 36.6 per cent and severe changes in 9.8 per cent of ears. There was a high incidence of blood around the point of insertion of the metal tags at three weeks old, but with the polyurethane tags only one calf showed slight evidence of blood around the point of insertion. In the beef cattle fitted with metal tags, a slight reaction was recorded in 40 per cent, a moderate reaction in 17 per cent and significant changes were found in 12 per cent of ears. By comparison, 16 per cent of ears with polyurethane tags showed only a slight reaction, and 80 per cent of the polyurethane tags were considered to be a good fit, compared with 37 per cent of metal tags. More changes were observed in the ears of the cull cows, with 23.5 per cent of ears with polyurethane tags being free from damage, compared with only 2.9 per cent of ears with metal tags.
Johnston
A M
AM
Department of Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, University of London, Hertfordshire.
Edwards
D S
DS
D000823:Animal Identification Systems / Q000662:veterinary*; D000827:Animal Welfare; D000818:Animals; D002417:Cattle / Q000293:injuries*; D004423:Ear / Q000293:injuries*