Operator error leads to ear ills, not tags
MORE sheep fitted with metal loop or plastic loop ear-tags suffered ear damage, and it was more severe, than when other tag types were used.
In a report in the Vet Record, May 29, David Edwards and Mac Johnston of the Royal Vet College, Herts, found six types of sheep tags used, in a RSPCA-funded study of 1040 ears.
But Mr Johnston stresses that operator error when the tag is inserted and hot weather, when flies can introduce infections at the tag site, contribute more to ear damage than tag type.
"Where tags are placed is crucial: Avoid blood vessels, putting them in too loose or too tight and too close to the base of the ear," says Mr Johnston.
It is normal for animals to have a slight reaction to newly fitted tags, these reactions persist for longer when metal loop tags were used. But many ewes in the study had been fitted with tags recently, adds Mr Johnston.
The study included 298 metal Ketchum-style loop tags, 334 two-piece rigid plastic tags, 168 Allflex style tags with a male and female part, 120 golf-tee shaped plastic tags, 93 one-piece rigid plastic loop tags and 22 one-piece flexible plastic flap-shaped ear-tags.
While metal loop and plastic loop tags were associated with the worst ear damage in the study, flexible, Allflex type tags made of polyurethane caused fewest problems.
Allflex style tags produce a neat, round hole more often than metal tags, which appears to reduce the opportunity for complications to develop. *