19 January 2001

Right tag procedure cuts losses

By Hannah Velten

WHEN to tag, type of ear tag and effective tagging methods must all be considered when identifying this years lambs, to avoid infections and tag losses.

Although lambs must be tagged with the flock mark of their holding of birth, careful planning and attention is important, says Mac Johnston, head of large animals at the Royal Veterinary College, Herts, where the first batch of 49 Dorset and Texel ewes lambed in late November.

The decision about when to tag will depend on the management system employed, workloads and weather, says Prof Johnston.

The college tags its lambs after birth when other routine tasks are done. "It is easier to catch them when they are young. We have the time and staff to do it at lambing and tags give us a means of identifying lambs which fits in with our management system," he says. But tagging before transport to market or abattoir should be avoided, he says. "Last-minute tagging may lead to mistakes, lambs will be further stressed and tags may be ripped out when they are mixing in confined spaces."

As long as tags clearly identify lambs with their holding, the legislation allows producers to decide which type of tag to use.

Research by Prof Johnston, in conjunction with the RSPCA, details which tags are most suitable for lambs and youngstock (see table).

Looped tags are especially unsuitable for young lambs, as they do not allow for growth. As the ear grows, its edge becomes indented, curls over, or the hole enlarges. When the hole drags through the ear this increases the risk of ear infection, he warns.

The college puts small, rigid plastic tags into lambs left ears. These are easy to use, cause minimum disruption to lambs and lead to few septic ears and tag losses, says Prof Johnston. But when tags are put into the ear properly then minimum losses and infections will occur, whichever suitable tag is used.

"Tags should lie flat against the ear and be placed between the two ridges of cartilage – avoiding blood vessels – and a third up from the base of the ear. Too near the ear canal and infection may occur but too near the ear tip will cause drooping and increase risk of ripping," he warns.

Hygiene is crucial to avoid septic ears, he says. "Tags must be kept clean and dry in a container."

Applicators must be disinfected regularly by dipping in boiling water, bleach or iodine. Tags which require the applicator to punch a hole in the ear should be avoided, as blood contact between lambs may spread diseases such as maedi visna, he adds.

Prof Johnston advises producers to think about the risks involved with incorrect tagging, to read leaflets that come with ear tags and seek vet guidance if in doubt. &#42

Research results on suitability of ear-tag type


Tag type Ease of Newborn lambs Youngstock

application

Two-piece flexible Good Poor, too bulky Good

Two-piece rigid Good Good Poor, too tight fitting

Aluminium loop Good Poor, major lesions Poor, major lesions

Plastic loop V good Risk of poor fitting Adequate

Golf-tee Poor Adequate Adequate

One-piece flap V poor Adequate Good

Tags should be no closer to the ear tip than this to avoid drooping and tag losses, says Mac Johnston.