It is well-established practice to identify an animal uniquely by means of an ear tag carrying a visible code, e. g. numbers, letters or a combination of these.

More recently, with a view to the automation. of animal identification, the practice of using electronic transponders has become widespread. These are components containing a microcircuit adapted, when stimulated by a suitable signal from an antenna near the animal, to emit a characteristic electromagnetic signal identifying the animal. By these means the animals can be electronically identified as they pass by the antenna, using a suitable reader to read the emitted characteristic signals.

Transponder modules, typically small cylindrical components, may be put in dense boluses which reside in the animal's stomach. Or, they may be incorporated in or attached to ear tags or other identifier devices attached on the outside of the animal.

A typical ear tag has first and second parts which can be opposed on opposite sides of the animal's ear.

Usually a sharp male part with a barbed tip is pushed through the animal's ear into a female part in which its tip is irreversibly trapped, so that the tag cannot thereafter be removed. The male and female parts may be separate, but more preferably they are provided at

opposite ends of a single element which folds around the edge of the ear in a loop, making unauthorised removal of the device more difficult.

Previous proposals for incorporating transponders in ear tags include WO 91/10982 and WO 95/04455, in which the transponder sits in an axial cavity of the spike on the male portion. EP 1084614 describes a discrete transponder housing with a small loop for attaching to a separate (e. g. conventional) tag. US 4718697 shows the transponder sandwiched between sheets defining two capsule halves which are welded together. Other documents describe flat annular transponder modules. EP 0754406 has a transponder in the form of a washer which fits around the male spike of a tag. WO 99/45760 shows a female component in the form of a disc with the transponder potted or encapsulated adjacent its rim. US 5588234 shows a conical tag body, either male or female, with the transponder coil extending around the base of the cone which has a central bore or spike for engagement with the other component.

What we propose are new constructions for an attachable animal identifier incorporating or adapted to incorporate a transponder. The new proposals are described with reference to ear tags, but the skilled person will appreciate that they may be applied with attachments adapted for securing to other parts of the body.

As mentioned, the context of our various new proposals is an animal identification device attachable to the animal, having two opposable parts which can be fixed to one another in opposition to attach the device to the animal; also a transponder component. Typically the transponder component is a generally straight and elongate unit rather than a flat open coil annulus as in some previous proposals, but the shape is not critical.

A first proposal is that, where one of the opposable parts of the device is a female part having an opening to receive a male element on the other part, the transponder is housed in a body portion at the female part, with a length axis of the transponder extending substantially radially (transversely) relative to the opening axis of the female part.

A second proposal is that, in a device of the kind described where the first and second opposable and engageable parts are connected by a link portion so that they form a loop when connected, the transponder unit which is preferably elongate is retained in a capsule region of the linked portion with its axis lying along the length of the link portion. The link portion may include a flexible region e. g. for folding around an animal's ear, the capsule region being stiff or less flexible and preferably directly adjacent one of the engageable parts. Preferably the link portion has an outer display surface adapted for marking with visual indicia-in the nature of a serial number-and most

preferably this is a plain surface which may extend onto and along the capsule region.

A third proposal is that a device of the kind described has a body defining an internal cavity to house the transponder, and the cavity has an insertion opening for the transponder, the opening being directed towards a connection axis of the first and second engageable parts, and/or, where a link portion is provided connecting those parts, is directed in the length direction of that link portion.

A further proposal is that a device of the kind described has a body defining a cavity to receive the transponder, the cavity having an insertion opening for the transponder which is accessible in the disengaged condition of the first and second parts, but in the engaged condition is blocked and/or locked. Preferably the transponder-cavity opening faces onto a female opening of the device so as to be blocked (or further blocked: it may already be closed) by a male member of the device when the parts are connected.

Where male and female parts are used their nature is not critical and may in itself be conventional, for example a simple circular opening for the female component, the male component being in the form of a spike with a barb formation at the tip to prevent withdrawal; the female component may have a cover for the tip of the spike after connection.

The reader will appreciate that all of the above proposals overlap and may be combined in preferred versions of the device. Thus, one preferred version is an attachable animal identification device having a male fastening member, a female fastening member adapted to receive the male fastening member in a locking manner and a loop link portion connecting the male and female portions, part of the loop link portion incorporating a cavity extending longitudinally of the link portion, preferably shaped so as to receive a rod-form transponder device, and having an insertion opening facing onto the part of the female member which receives the male member.

A printable (or printed) display surface is provided along the outer side of the link portion.

Preferably the entire unit is formed as a one piece integral whole of plastics material, e. g. by moulding.

Embodiments of our proposals are now described in detail with reference to the accompanying drawings in which Fig. 1 is a perspective view of an ear tag; Fig. 2 is an axial cross-section at the female end of the tag of Fig. 1, somewhat enlarged, and Fig. 3 is an end view of the female end.

With reference to Fig. 1, an ear tag is made as a one-piece moulded plastics entity e. g. of nylon, polyurethane or other suitable plastics material: generally it should be UV-resistant and laser-printable.

It has a female end 1 and a male end 2 connected by an elongate strip portion or link 3.

At the male end, the generally rectangular strip portion 3 enlarges into a circular platform 21 providing a base for a tapered engagement spike 22 with a tip barb 23 and an end point 24. The spike projects from the flat upper (inner) surface 4 of the strip 3.

The central part of the strip or link 3 has a reduced thickness portion or waist 31 to enhance flexibility, so that the tag can be folded around an animal's ear to oppose the male and female ends 1,2 through the ear.

At the female end 1, the tag provides an engagement face 11 with a central hole 12 dimensioned so that with substantial force the barbed spike 22 of the male end 2 can be pushed through it and then held irremovably in place. Towards the female end the tag has been moulded around a longitudinal mould projection so as to define an internal cavity. Extending from the link waist 31 towards the female end this provides the cavity for a transponder capsule 5 of generally uniform cross-section and elongate in the length direction L of the tag strip 3, to hold a generally cylindrical transponder module 6 which in itself may be conventional. The transponder module may simply be pushed or dropped during manufacture into the housing cavity from its end opening 51 (see Fig.

2), which faces onto the larger end opening 52 of the female part 1.

The transponder module 6 is easily inserted in its cavity 5 through the enlarged end opening 52 of the tag at the female end, and may then be blocked or sealed in place with a polymeric or adhesive plug. When the male spike has been pushed into place with the tag in situ on an animal's ear (not shown), the spike 22 further blocks the opening, keeping the transponder module 6 safely in place. A possible refinement to this design (not shown) is to form a portion integral with the upper wall 16 of the cage, e. g. a partially cut-out portion defining the insertion hole 12, so that when the spike 22 is pushed through it will fold the additional portion down (arrow B in Fig. 2) into the inner opening 51 of the transponder cavity 5, blocking and sealing the transponder more effectively into its housing.

The female end 1 forms a cage with an outer cover wall 15. With the male spike 22 locked into place, as shown in Fig. 2, this cage masks the locked end of the spike so protecting it from catching external objects and also protecting it against unauthorised interference or accidental damage which might undo the tag.

Typically a tag needs to carry a visual code in addition to the transponder. Typically this may be quite a lengthy alphanumeric series, e. g. letters indicating a country, numbers indicating an area, further numbers indicating a farm and still further numbers being the serial number for the individual animal. The present design is advantageous in that on its outside surface 32

(i. e. the underneath as indicated in Fig. 1) it presents a long plain laser-printable surface which extends onto the undersurface of the capsule 5 if necessary.

We also find that the illustrated incorporation of the transponder into one length of the loop link leads to the transponder lying in a favourable orientation for reading in use. At the same time, it gives a loop-form tag incorporating a transponder with minimal extra plastic, helping to keep weight down for the very small tags required e. g. for new lambs.

Fig. 3 shows a refinement at the female end, showing how the circular engagement face 11 extends out laterally as engagement lugs or ears 14 which are for gripping, in concert with the circular platform 21 at the male end, by an applicator tool when joining up the tag. To reduce the chance of the tool slipping out of alignment, with potential malfunction and/or wear of the applicator tool, the undersurfaces 141 of these lugs 14 are inclined or bevelled upwards towards the centre to serve as a centering guide.