AU2006202715B1 - Treatment of sheep to reduce fly strike - Google Patents

Description

S&F Ref: 762482

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address of Applicant Actual Inventor(s): Address for Service: Invention Title: Australian Wool Innovation Limited, an Australian company, ACN 095 165 558, of Level 16-20 Barrack Street, Sydney, New South Wales, 2000, Australia Aaron Anthony Arnold Steven Noel Corboy Paul van de Loo Robert Eric Powell Julie Anne Dorrian Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Treatment of sheep to reduce fly strike Associated Provisional Application Details: [33] Country:

AU

[31] Appl'n No(s): 2005903359 [32] Application Date: 24 Jun 2005 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c TREATMENT OF SHEEP TO REDUCE FLY STRIKE SField of the invention This invention relates to a method of treating sheep in order to reduce the i problem of fly strike. The invention also relates to devices for use with this method.

Background of the invention A well documented problem experienced by many sheep and wool producers Srelates to the occurrence of fly strike in and around the breech region of sheep. The O breech region is defined as the region encompassing the tail, crutch, perineum and Ssurrounding skin tissue of the sheep. Where the breech area of the sheep is not 1o appropriately maintained, it is subject to soiling by faecal matter and urine which is an attractant for the gravid fly female to lay eggs, resulting in an enhanced fly strike rate.

Breech strike, as it is known, is the primary form of fly strike accounting for more than of all fly strike.

Farmers use many methods to control breech strike including chemical application by jetting and spraying, timing of shearing and crutching to coincide with known times of high fly challenge. In addition, the control of diarrhea by good worm control and nutritional management reduces incidence of breech strike. However, no method is permanent and all leave sheep vulnerable to breech strike at certain unpredictable times.

Regular crutching of sheep, that is, shearing of wool from the breech region of the sheep, is a partially effective preventative method in at least drier localities. However, crutching needs to be done reasonably regularly in order to be effective, and is thus laborious and adds significantly to the overall cost of wool production. Also, crutching alone, whilst assisting with dealing with fly strike, is not a complete solution to the problem. A further problem is that sheep generally have loose folds of skin in the breech region, and moisture caught in the folds of the skin results in bacterial growth and an odour that creates fly attractant sites where fly strike is likely to occur.

Accordingly, methods to tighten the skin and permanently remove wool from the breech region of sheep have been investigated for many years. One such procedure, known as a mulesing operation, was developed by John Mules during the early 1930s and involves the surgical removal of folds of skin in the breech region of the sheep in order to tighten the skin to thereby reduce the folds of skin in this region, and increase the area of flat, bare skin.

R:\LIBLL]18604.doc The original mulesing operation involved pinching a fold of skin on either side of the perineal area with specially designed pincers (Burdizzo pincers) and cutting the fold off with a knife. This operation was considered, at the time, not to be painful because of the pressure of the pincers on the skin and nerve endings. Once the fold of skin between the pincers had been sliced off, the pincers were removed and the wound allowed to heal. This operation has been modified over the years to remove skin on or adjacent the tail region of the sheep and also in the crutch region. More radical procedures involve the removal of skin from the tail, the so called "Radical Mules Operation".

Once the wounds caused by the mulesing operation have healed, the skin around the crutch region of the sheep is generally pulled tighter, thereby expanding the naturally occurring bare area of skin around the anus and in the perineum region of the sheep, thereby reducing the problem of soiling in this region, and hence reducing the incidence of breech fly strike.

The mulesing operation, in one form or another, is widely practiced in Australia Is and indeed some 10-15 million lambs undergo a mulesing operation each year in Australia. Whilst it is generally accepted that the mulesing operation is painful to sheep and hence a less than desirable method of treatment, the fact remains that the mulesing operation is currently the most effective form of breech fly strike prevention available to farmers. Other currently available treatments, whilst being far more labour intensive and generally requiring ongoing or repeat treatments, are simply less effective in dealing with the fly strike problem.

The mulesing operation is not, however, without its problems. One of the main problems with the mulesing operation is that it is painful and animal welfare considerations have long demanded a change to this practice. In addition, the wounds resulting from the operation are subject to infection. The wounds also take a significant period of time to heal which results in stress to and reduced growth of the lambs.

There has been, accordingly, significant pressure to find an alternative to the mulesing operation, which is less painful and injurious to the sheep, but which will provide at least some of the advantages of the mulesing operation, specifically the long term reduction in fly strike in the breech region.

Over the years various attempts have been made to chemically treat the breech region of sheep in order to reduce the incidence of fly strike. Chemically based approaches have generally fallen into two broad categories, that is, so called "chemical mulesing", and temporary or permanent hair depilation.

(R:\LIBLL) 8604docLzv Chemical mulesing was attempted as early as the 1930s (the Manchester operation) in which a caustic chemical was applied to the sheep (AU Patent 107994).

However, this approach never gained widespread acceptance as it resulted in large granulated wounds and was considered cruel and caused more problems than conventional mulesing.

Other approaches of this type were explored in the 1970s by Pratt and Hopkins, and others. Injections of zinc sulphate, chloral hydrate and potassium iodine caused death of the skin followed by scarring. AU Patent Application No. 46610/79 discloses a formulation which was commercialised at that time. However, these attempts at dealing 1o with the problem were rejected for a number of reasons, such as that the wounds caused by the treatment were slow to heal, and the treatment was adversely affected by breech wrinkles. Operator safety and sheep toxicity were also considered to be problems.

AU Patent Application No. 73793/91 discloses a further attempt to develop a chemical composition suitable for chemical mulesing. It was however found that the treatment caused pain and discomfort to treated sheep which was similar to surgical mulesing. Also, operator safety and sheep toxicity issues were of concern, and commercialisation was abandoned. International Patent Publication No. WO 00/71089 discloses an attempt using chemical formulation and high intensity light to achieve long term depilation. Whilst this approach has certainly shown that the method is reasonably effective protection against breech strike, it is not as effective as surgical mulesing. Also, depending on the age of the animal at treatment there was a varying degree of permanence of depilation. US Patent Application 2005/0072372 discloses another depilation formulation.

Other treatment regimes which have been considered, but rejected for other reasons, or which require ongoing research in order that their efficacy or the correct treatment regimes can be assessed, have included freezing, high energy electron treatment, and intradermal collagenase treatment.

It will thus be appreciated that currently proposed chemical and physical treatments which cause wool break and temporary wool loss are less than effective forms of treatment. Treatments which result in full thickness necrosis of the skin have their own problems, and are not necessarily a more humane treatment regime than mulesing. There thus remains a strong need for a method of treatment which will satisfy animal welfare concerns and yet will provide an effective treatment for reducing the incidence of fly strike in the breech region.

[R:\LIBLLI8604 doc Izv Object of the invention It is the object of the present invention to substantially overcome or at least ameliorate one or more of the disadvantages of the prior art.

Summary of the invention Accordingly, in a first aspect, the present invention provides a method of treating the breech region of a sheep, said method comprising: providing a clamp having a pair of opposing elongate jaws; applying the clamp to a fold of skin in the breech region with a clamping force between the elongate jaws sufficient to substantially starve the fold of skin of blood lo supply; maintaining the clamp in place until the fold of skin atrophies.

Preferably, the method further comprises maintaining the clamp in place until the atrophied fold of skin becomes detached from and falls off the sheep together with the clamp.

Preferably the method comprises the steps of applying a plurality of clamps to the breech region and optionally to the tail or tail region. In the preferred form of the invention, one clamp is applied to one side of the perineum and another clamp applied to the other side of the perineum. Preferably the clamps are aligned so that the folds of skin on opposite sides of the perineum converge towards the crutch. Optionally, the invention further involves applying clamps above and/or below the perineum. Preferably, one or more clamps are applied to or adjacent the tail of the sheep.

The clamp may be applied to the fold of skin using a tool or applicator, said tool or applicator adapted to apply the requisite clamping force to the clamp, the clamp being provided with means for maintaining the clamping force on the fold of skin after the tool or applicator has been removed.

The clamping force is preferably sufficient to completely starve the fold of skin of blood supply, but not so high as to cut the skin. In the preferred form of the invention the clamp should remain in position on the sheep for at least 48 hours, and preferably at least 72 hours.

In the preferred form of the invention the skin immediately below the clamp welds together, and the clamp is retained in position for a time period sufficient for that welding to occur, such that when the atrophied fold of skin becomes detached from the sheep, no open wound results.

[R:\LIBLL] 18604.doc:lzv IND The term "weld" or "welding" used in this specification is intended to describe the joining or growing together of the two sides of skin underneath the clamp to form a healed, closed scar. It is understood that the collagen in the skin aggregates together and a 0 Z fibrin/wound repair process takes place to give a temporary join or union of the skin until remodelling of the cells takes place.

In a second aspect, the present invention provides a clamp adapted to clamp a t fold of skin in the breech region of a sheep, the clamp having: a pair of opposing elongate jaws, each jaw having a clamping edge; and a locking mechanism adapted to lock the two jaws in a closed configuration, wherein the clamping edges are substantially adjacent and opposing one another; wherein the clamp is sufficiently resilient to be locked in the closed configuration with the fold of skin clamped between the clamping edges and to apply a clamping force sufficient to substantially starve the fold of skin of blood supply; and wherein end portions of at least one clamping edge are supported by resilient Is supports to allow resilient deformation of the at least one clamping edge.

In a preferred embodiment, the resilient supports are spring supports.

In a further preferred embodiment, the elongate jaws are provided with transverse ridges extending generally normally to the clamping edges, the ridges being adapted to engage the fold of skin and substantially prevent longitudinal sliding of the clamp relative to the fold of skin. Preferably, the elongate jaws are provided with a single ridge on one jaw and a pair of ridges on the opposing jaw, wherein the single ridge is longitudinally spaced between the pair of ridges on the opposing jaw. Desirably, the ends of the clamping edges are curved to resist sliding movement of the fold of skin over the end of the clamping edges.

The elongate jaws preferably have a length of between 5 cm and 15 cm.

Optionally, the clamp is adapted to maintain the clamping force for a time period sufficient for the fold of skin to atrophy.

Preferably, the elongate jaws are pivotally joined at a fixed end of the clamp and the locking mechanism is provided at an opposite free end of the clamp.

The jaws may be urged together by an applicator, or an urging means may form part of the clamp. Where the urging means is part of the clamp it may be resilient, in the form of a spring or elastomeric band or bands. The urging means may also serve to hold the two jaws together or the urging means and the means for holding the jaws together may be independent of each other.

AH21(389699_1I DOC) the two jaws together or the urging means and the means for holding the jaws together may be independent of each other.

The locking mechanism for holding the jaws together may comprise one or more fasteners associated with one of the jaws which engage with retaining means associated with the other of the jaws. The fasteners may comprise pins, screws, rivets or hooks.

There may be a series of fasteners extending along the length of the one jaw which engage in cooperant holes or recesses located in the other jaw. The fasteners may be adapted to pass through the fold of skin to thereby ensure the clamp is held in position until the fold of skin atrophies. Preferably, the locking mechanism comprises a pair of opposing hooks, one on each elongate jaw, the hooks adapted to resiliently deform and engage one another when the elongate jaws are pressed together at the free end of the clamp, to lock the free end of the clamp in the closed configuration.

The clamp may be curved with a concave surface to generally conform to the shape of the breech region of the sheep and an opposite convex surface.

Brief description of the drawings A preferred embodiment of the present invention will now be described, by way of an example only, with reference to the accompanying drawings wherein: Figure 1 shows the rear end of a sheep having a pair of clamps according to the invention fitted thereto; Figures 2 to 19 show various embodiments of clamp according to the invention; Figures 20A and 20B show an applicator for applying the clamp of Figure 17; Figure 21 shows a dispenser for dispensing the clamp of Figure 17; and Figure 22 shows a sheep with the clamps of Figures 17 and 19 applied.

Detailed description of preferred embodiments Referring initially to Figure 1, a female sheep 10 is shown with two pairs of clamps 12, 14 (also called "clips") fitted to the breech region of the sheep 10. A first pair of clamps 12 are arranged on either side of the perineum 16 of the sheep 10. A second pair of clamps 14 are arranged on either side of the tail 24 of the sheep 10. Male sheep will have the clamps placed in similar locations.

The clamps 12, 14 comprise a pair of jaws 18 that are adapted to be clamped together. In performing the method, the clamps 12, 14 are each applied to a fold of skin in the breech region, with a clamping force between the jaws 18 that is sufficient to substantially starve the fold of skin 20 of blood supply. The clamps 12, 14 are then left in place until the folds of skin 20 atrophy and fall off the sheep 10 together with the clamps [R\LIBLLJ 18604.docz 12, 14. This process stretches the skin in the breech region of the sheep 10, expanding the area of bare skin around the perineum 16 of the sheep The location of the clamps 12, 14 shown in Figure 1 is intended to be indicative of where and how clamps might be positioned. However, it is envisaged that other adjacent locations might be preferable. Indeed, clamps applied to the crutch region 26 are also envisaged to thereby tighten the skin in an annulus around the perineum 16 of the sheep It is to be noted that in the specification the term "sheep" is to be interpreted broadly and to include in its scope other animals of the sheep family which suffer from io fly strike problems in the breech region.

The purpose of the clamps is in effect to remove folds of skin from around the perineum of the sheep so as to lift the woolly skin up and away from the perineum and to stretch the skin in that region, so as to substantially prevent contamination of the woolly skin with urine and faecal matter during the life of the sheep. However, rather than slicing off the folds of skin, as is done during the mulesing operation, the skin is simply nipped hard between the jaws of the clamp. Blood supply to the fold of skin is cut off and consequently, over a period of time, the fold of skin atrophies. The two sides of the skin in contact with each other, that is, between the jaws of the clamp, weld together during this atrophication process. Once the two sides of the skin have welded together, the atrophied fold of skin drops away from the sheep, together with the clamp, thereby leaving a vertical scar on either side of the perineum of the sheep, with the skin in the perineum region having been pulled tight during the clamping operation. The wound caused by clamping the skin will be sealed closed at the time the fold of skin falls away, thereby never exposing the wound to contamination and infection. Thus, the beneficial effects of mulesing can be obtained using a clamping arrangement as described, without incurring the consequences of an exposed mulesing injury as discussed above.

To achieve a satisfactory welding of the two sides of the skin during the clamping operation, the clamping force should ideally be neither too strong or too weak.

If the clamping force is not strong enough, the clamp might fall off prematurely, and a proper welding of the two sides of the skin will not take place, whereas if the clamping force is too strong, the jaws of the clamp will tend to cut into the skin of the sheep, thereby causing skin breakage before the two sides of the skin have welded together, and thereby creating an open wound which will be subject to infection, as well as being injurious to the wellbeing of the sheep.

R:\LIBLL] I 604 doclv It is envisaged that the clamping operation will not be greatly detrimental to the wellbeing of the sheep since within a relatively short period of time the nerve endings between the clamp edges will have been shut off. Experiments to date have indicated that the discomfort felt by sheep having a clamp of the aforementioned type applied to the breech region is far less severe than the discomfort caused by the mulesing operation.

Indeed, it is found that within a relatively short period of time the sheep is completely unaware that the clamp has been applied.

It will be appreciated that many different types of clamps and clamping systems can be used. It is desirable that the clamps themselves do not cause any environmental damage when the fold of skin and clamp falls off the back of the sheep. Accordingly, some form of biodegradable clamp is desirable although not essential. Plastics materials are known which degrade over time under the influence of ultraviolet light. It would also be possible to form the clamps from wood, or other naturally occurring materials, which will degrade over time without causing environmental damage. The clamps will typically need to retain their strength for no more than about two or three weeks at most, that is, the period in which it takes for the atrophied skin to drop off the sheep.

Various different embodiments of clamp are disclosed below. It will, however, be appreciated that the design of clamp can vary quite considerably from the different embodiments disclosed herein. The preferred clamp would be relatively quick to apply to the sheep, would maintain its clamping force for the intended duration of the clamping operation, and, as mentioned above, would be biodegradable. The clamp will effectively comprise a pair of jaws, generally of elongate shape, typically approximately 10cm long and having opposed clamping edges between which the fold of skin will be nipped. It is envisaged that some resilience in either the clamping edge or the jaw itself will be preferable so that a relatively uneven fold of skin and wool may be gripped between the jaws, but a reasonably even gripping force is applied along the length of the jaws. For this reason, some degree of flexibility in the clamp and specifically the clamping edge is desirable. The clamp and clamping edge may be non-planar so as to follow the contour of that part of the sheep where the clamp is to be applied. The underside of the clamp may, for example, be of generally concave shape.

The preferred arrangement is that an appropriate clamping force be maintained on the fold of skin, even after the fold of skin begins to atrophy. As the two layers of skin clamped between the clamping edges of the clamp begin to die, the thickness of these two skin layers will tend to decrease. The clamping force on the two layers of skin should continue to be maintained, even though the thickness of the skin layers being clamped is [R \LIBLL]IS604 doc lzy IND decreasing. Thus, some degree of resilience in the clamp is highly desirable. Preferably some form of resilient urging means is incorporated into the clamp such that, even though Sthe clamp jaws are moving together over time, the clamping force will be maintained, at or around the initial clamping force applied by the clamp at the time of first application to C, 5 the sheep.

As shown in Figure 2, a clamp 30 is comprised of jaws 32 each of which has an inwardly facing edge 34, the two edges 34 being aligned with each other and facing towards each other so that when the jaws 32 are moved towards each other a fold of skin Sclamped between the edges 34 will be nipped in the manner described above. The two IN 1o jaws 32 are joined together by a pair of threaded bolts 36, rotation of the bolts 36 being Sused to move the jaws 32 either towards each other, or away from each other, depending on the direction of rotation. Thus, an applicator would typically be used to drive the bolts 36, thereby moving the jaws 32 together, the applicator having a torque control mechanism to ensure that the bolts 36 are not over tightened which would otherwise cause the edges 34 to cut into the skin of the sheep. The jaws 32 may be slightly bowed so that at their centres they are closest together. This will provide a resilient clamping force over the full duration of the clamping operation.

The clamp 40 shown in Figure 3 of the drawings comprises a pair of curved jaws 42, each having a bevelled edge 34 which face towards each other, the two jaws 42 being pivotally connected together about pivot pin 46. A locking catch 48 is located on the end of one of the jaws opposite the pivot 46, the catch 48 being used to hold the two jaws 42 together in the closed position. Typically some form of lever device will be required in order to close the jaws 42 on a fold of skin. The jaws 42 will be made of a resilient or flexible material so that when the jaws 42 are closed on a fold of skin the flexibility of the jaws 42 will allow irregularities in the fold of skin to be accommodated and also ensure that a substantially even clamping force is applied along the length of the jaws 42. The resilience in the jaws 42 and the curvature of those jaws 42 will facilitate an ongoing clamping force being applied to the fold of skin, even where the fold of skin reduces in thickness over time.

The clamp 50 shown in Figures 4A to 4C of the drawings comprises a pair of jaws 52 held together by a flexible strap 54, one of the jaws 52 carrying a series of pins 56 which locate in holes 58 in the opposite jaw 52. The pins 56 are provided with a series of corrugations 59 on the outer surface thereof which lock with barbs (not shown) in the holes 58 to thereby hold the pins 56 in the holes 58. It is envisaged that the two jaws 52 will be urged together, using some form of urging tool or applicator to thereby drive the [R:\LIBLL]I 8604doc:lzv \pins 56 through the fold of skin and thereby effectively retain the clamp 50 on the fold of Sskin. Thus, in this embodiment, not only does the clamp 50 grip onto the fold of skin, but Sthe pins 56 will pass through the skin to securely lock the clamp 50 onto the fold of skin.

The interaction between the corrugations 59 and the holes 58 will be such that the two jaws 52 will be held together in the clamped arrangement once the clamp 50 has been fully pressed closed using the applicator.

tt The clamp jaws 52 shown in Figure 4 may each be supplied in the form of a continuous strip of material, say for example 50m long. An applicator (not shown) which Smight be in the form of say a pair of shear-like jaws would include a guide path for each IN 10 of the two strips, with a form of drive arrangement for feeding the strips into face to face Spositions on the respective shear-like jaws. The jaws 52 will then be closed onto the fold of skin, in the manner described above, driving the pins 56 in one clamp jaw 52 through the holes 58 in the opposite jaw 52. A cutter will then cut off the two clamp jaws 52 from their respective strips, and the applicator will then be ready to apply a further clamp 50 to is another position on the sheep, or to another sheep.

It is envisaged that the pin type clamping connection will cause an increased pain for the sheep and, accordingly, might not be as acceptable as the other embodiments disclosed herein for animal health and welfare reasons. The puncturing of the skin will be susceptible to infection. To mitigate animal welfare concerns due to pain of application, and also to substantially prevent infection, it will be possible to coat the pins 56 with an antiseptic and anaesthetic coating. Although the anaesthetic coating would not reduce pain at the time of application, ongoing pain should be significantly reduced by anaesthetic until such time as the clamping action has severed or blocked off the nerve endings to the fold of the skin.

The clamp 60 shown in Figure 5 of the drawings is a relatively simple embodiment and comprises a pair of dowels 62 which serve as the two jaws of the clamp.

The dowels 62 are, in use, held together by a pair of o-ring type elastomeric bands 64 which locate in grooves 66 formed in the end of the dowels 62. The dowels 62 as shown are round in cross section but it will be appreciated that if a more precise clamping is required, dowels having a sharpened inner edge could equally well be used. Wooden clamping jaws have the advantage that they will naturally degrade within a relatively short period of time once they have dropped off the sheep. Also, it will be appreciated that they are relatively inexpensive components although it is envisaged that some form of applicator will be required in order to install the rings 64 into position.

R:\LI BLL] 18604.do: Izv 11 The clamp 70 shown in Figures 6A to 6D of the drawings includes a pair of jaws 71, each having a clamping edge 72 which is connected to the jaw 71 via a series of resilient springs 76. The springs 76 will, when the clamp 70 is in position, continually urge the edge 72 towards the adjacent edge 72. The two jaws 71 are connected together via ratchet-type connectors 78. The two jaws 71 will be pressed together, and the ratchet connectors 78 will hold the jaws 71 in their clamped-on condition. The resilience of the springs 76 will ensure the clamping force is maintained on the fold of skin until the fold atrophies and drops off in the manner discussed above. Thus, for the duration of the clamping action, a continuous resilient clamping action will be provided on the fold of 1o skin to thereby effectively keep the pressure on that fold, and hopefully result in efficient cutting off of the blood supply and hence atrophy of the fold of skin, the welding of the two sides of the skin together, and healing of the wound.

The clamp 80 shown in Figure 7 of the drawings is, in effect, an elongate bulldog-type clip and is comprised of a length of spring steel shaped so as provide a pair is of jaws 82 continuously urged together along the length of the jaws by the integral spring steel body 84 in known manner. The fold of skin will be located in the triangular gap 86 between the jaws 82 and, provided an appropriate clamping force between the jaws 82 can be achieved, a relatively efficient device will be obtained. The clamp 80 shown in Figure 7 is not shown with any means for moving the jaws 82 apart from each other, although it is envisaged that the applicator device used for installing the clamp into position will include the necessary means for holding the jaws 82 apart in order to admit the fold of skin into the triangular gap 86.

Turning now to Figures 8A to 8C of the drawings, a one piece clamp 90 is shown having a pair of jaws 92, each of which supports a respective clamp edge 94, the two clamp edges 94 being mounted to the jaws 92 via flexible spring arrangements 96. As is clear from section B-B in Figure 8C, the spring arrangements 96 are mounted at an angle of approximately 45 degrees to the plane of the clamp 90 such that the clamping edges 94 are angled upwardly, and away from the body of the sheep. It is envisaged that the fold of skin will be pulled upwardly, through the gap 95 between the two jaws 92, and the clamping edges 94 will then act in the manner of barbs to hold and retain the skin, and prevent it moving backwardly through the gap 95. The natural resilience of the skin will thus act to hold the fold of skin under tension with the clamping edges 94 nipping the fold, and providing the necessary clamping force to cut off the blood supply to the fold of skin located outside of the clamp [R:\LIBLLII8604 doc:lzv 12 \Figures 9A to 9C of the drawing depicts a clamp 100 comprising a pair of jaws S102, curved slightly as shown, and having opposed clamping edges 104 facing towards Seach other. The two jaws 102 are pivotally connected together at one end 106 thereof.

The opposite ends 107 of the jaws 102 each have a securing hole 108 therein such that when the clamp 100 is installed on the fold of skin and the two jaws 102 are brought into operative alignment with each other, the holes 108 will then be in register with each other and a securing pin (not shown) can be located through the two aligned holes 108 to thereby hold the clamp 100 in position. The curved nature of the jaws 102 will ensure that Sa resilient clamping force provided by the jaws 102 is maintained, even when the fold of IND 10 skin reduces in thickness as it atrophies. Furthermore, it will be noted from section A-A in SFigure 9C that the clamping edges 104 have a square configuration as shown to ensure that although the clamping edges 104 will cut off the blood supply, they are not so sharp as to cut into the skin of the sheep. It is envisaged that the clamp 100 will be formed of a resilient yet preferably biodegradable plastics material.

The clamp 110 shown in Figures 10A to 10C of the drawings, is a slightly different concept and comprises a pair of roller jaws 112 which form the clamping jaws of the device. The roller jaws 112 are rotatably mounted on end plates 114. The peripheral outer surface of the roller jaws 112 are provided with a series of ribs or barbs indicated at 116 in section A-A of Figure 10C. Optionally the end plates 114 will include means to ensure that the roller jaws 112 can only rotate in one direction. In use it is envisaged that a fold of skin will be drawn in the direction of arrow 118 into the gap 119 between the rollers 112, and once the fold has been drawn into that gap 119 the roller jaws 112 will serve to nip the fold of skin, in the manner of a mangler, to thereby effectively clamp the fold of skin and cut off the blood supply to that fold. It will be noted that the roller jaws 112 include a central axle or hub 113 and an outer cylindrical shell 115. The shell 115 is connected to the hub 113 by means of a series of flexible webs 117 which serve to allow for resilient deflection of the shells 115 to thereby facilitate the ongoing resilient gripping of the fold of skin by the two roller jaws 112.

The clamp 120 shown in Figures 1 1A to I I1C of the drawings is similar to that of Figures 10A to 10C embodiment but the roller jaws 122 have a paddle wheel type structure in which a series of four clamping jaws 124 are spaced apart around the periphery of the roller jaws 122, as shown. Once again, a fold of skin will be drawn between the two roller jaws 122 and once drawn up between the roller jaws 122 it will be gripped by the rotary-type clamping jaws 124 and held in that position until the fold atrophies in the manner described above. The roller jaws 122 also include a central hub IR\LIBLLJ]18604 doclzv 13 126 and a series of spring like connectors 128 which connect the clamping jaws 124 to the hubs 126.

Figures 12A to 12C of the drawings depict a clamp 130 having a pair of jaws 132 pivotally connected together via pivot means 134 at one end thereof and having hook means 136 at the opposite end thereof around which one or more elastomeric bands (not shown) can be located in order to urge the two jaws 132 together. The jaws 132 have clamping edges 138 on the inner edges thereof which will serve to grip the fold of skin in the manner described above when operatively installed on a sheep. In this embodiment, the jaws 132 are separately manufactured from the pivot means 134 and hook means 136.

The pivot means 134 and hook means 136 are formed from different materials from the jaws 132. Thus, for example, the jaws 132 might be formed of metal or other hard material, whereas the pivot means 134 and hook means 136 might, for example, be formed from an inexpensive moulded plastic material.

The clamp 140 shown in Figures 13A to 13C of the drawings comprises two identical jaws 142 of plastics material which are joined together by pins 144 to hold the two jaws 142 together in the manner discussed above with reference to Figures 4A to 4C.

Clearly the jaws 142 can be made relatively inexpensively and are particularly suited to the feed arrangement discussed above with reference to Figures 4A to 4C. The clamping edges 146 are separated from the remainder of the jaw 142 by gaps or cut-outs 148 to provide for the resilience in the clamping edge 146, as discussed above. It will be noted that the jaws 142 have regularly spaced bores 149 therein to receive the pins 144 and thereby hold the two jaws 142 together when operatively installed on a fold of skin.

The clamp 150 shown in Figures 14A to 14C of the drawings is similar in concept to the "bulldog clip" type clamp discussed with reference to Figure 7 of the drawings. The clamp 150 includes a spine 152 which supports a series of arcuate springs 154, each of which is connected to a jaw 156 as shown. The two jaws 156 each have an inwardly facing clamping edge 158 on the inner edge thereof which will serve to grip the fold of skin in the manner discussed above in order to install the clamp 150 on a fold of skin. The jaws 156 will be urged apart using an applicator of some description and then clamped onto the fold of skin whereafler the springs 154 will retain the clamp 150 with an appropriate clamping force on that fold. The separate nature of the springs 154 and the relative narrowness of the jaws 156 will ensure that the jaws 156 are able to flex somewhat to accommodate the irregularities in the fold of the skin, and the individual springs 154 will be able to accommodate that flexure.

[R \LIBLL) 18604doczv The clamp 160 shown in Figures 15A to 15C of the drawings is similar to that shown in Figure 3 of the drawings. However, in this embodiment, the clamping edge 162 is connected to the jaws 164 via spring means 166 which allows for the necessary flexure of the clamping edge 162. The two jaws 164 are pivotally connected together via a web 167 at one end thereof, and locking means 168 is provided at the opposite end of the two jaws 164 to allow the jaws 164 to be locked together in the clamping position in use. It is envisaged that the clamp 160 will be formed as a one piece plastic moulding.

The clamp 170 shown in Figure 16 of the drawings is formed of a lightweight plastics material but is similar to the dowel embodiments shown in Figure 5 of the drawings. The clamp 170 comprises a pair of jaws 172, each having a relatively sharp clamping edge 174 along the inner edge thereof. The jaws 172 each have grooves 176 on opposite ends thereof adapted to receive o-ring type elastomeric bands to urge the two jaws 172 together. It is envisaged that the jaws 172 will be formed in an injection moulding, or similar process, of a lightweight inexpensive plastics material.

Figure 17 depicts a clamp 200 formed as a single integrally moulded piece similar to the clamp 160 depicted in Figures 15A to 15C. The clamp comprises a pair of opposing elongate jaws 202, each jaw 202 having a clamping edge 204. The jaws 202 extend between a fixed end 206 of the clamp 200, at which the jaws 202 are pivotally joined, and a free end 208, at which a locking mechanism comprising an opposing pair of hooks 210 is provided. The hooks 210 are adapted to be pressed past one another and lockingly engage the two jaws 202 at the free end 208 of the clamp 200. The jaws 202 are also provided with three inwardly facing transverse ridges 212. A single ridge 212 is provided on one jaw 202 and a pair of ridges 212 is provided on the opposing jaw 202, such that the single ridge 212 is longitudinally spaced between the pair of ridges 212.

Accordingly, when the free end 208 of the clamp 200 is closed, the transverse ridges 212 force the fold through an S-bend, which increases the load required to move the clamp 200 longitudinally along the fold. The clamping edges 204 curve upwardly at each end to resist sliding movement of the fold of skin over the end of the clamping edges 204. The clamp 200 is formed with resilient spring supports 214, which allow the clamping edges 204 to resiliently deform and thereby, more evenly distribute pressure from the clamping edges 204 along the fold. At each end of the clamp 200, protrusions 215 are provided. In order to arrange multiple clamps 200 in a stack, a bead of glue is placed on the protrusions 215 at each end of the clamp 200. Another clamp is then placed on top of the clamp 200 such that the beads of glue join the corresponding protrusions 215 of the two clamps. When removing a clamp 200 from the stack, the bead is easily removed due to [R:\LIBLL 18604 doc:lzv its low adhesion with the clamps 200, but provides a relatively rigid stack of clamps 200.

The protrusions 215 also assist the glue beads to pool, which ensures a neat consistent finish.

Turning to Figure 18, an alternative clamp 220 is depicted. The clamp 220 is designed to be applied to a fold of skin along one side of the tail of a sheep, similar to the second pair of clamps 14 depicted in Figure 1. The main difference in the design of the clamp 220 is that the clamping edges 224 have a curved portion 228 at the fixed end 226 of the clamp 220. This design allows a curved fold of skin taken from the edge of the tail to where the tail joins the perineum to be clamped.

Figure 19 depicts an alternative clamp 230, which in essence is the equivalent of two of the clamps 220, depicted in Figure 18, joined back to back. The clamp 230 comprises two lateral elongate jaws 232 each opposing a central jaw 233 to form two pairs of opposing jaws 232, 233. Each pair of jaws 232, 233 having opposing clamping edges 234, each of which has a curved portion 228 at the fixed end 236 of the clamp 230.

The clamp 230 is designed to be applied over the tail of the sheep, with each pair of clamping edges 234 being applied to a curved fold of skin on one side of the sheep's tail.

Referring now to Figures 20A, 20B and 17, an applicator 240 is shown for use in applying the clamp 200 depicted in Figure 17. The applicator 240 has a pair of arms 242 operatively associated with a pair of handles 244 and a trigger 246. The arms 242 are provided with pins 248 and tabs 250. The clamp 200 is mounted on the applicator by inserting the pins 248 into recesses 216 provided on each jaw 202 at the free end 208 of the clamp 200. The applicator 240 is then pressed down over the fixed end 206 of the clamp 200 until a latch 252 of the applicator 240 engages a flange 217 provided at the fixed end 206 of the clamp 200. The tabs 250 on the applicator arms 242 engage a rib 218 on each jaw 202, to prevent the clamp 200 sliding out from the applicator 240. Once the clamp 200 is loaded in the applicator 240, the clamp 200 can be opened by pulling back the trigger 246. The clamp 200 can then be applied to a fold of skin by pressing the handles 244 together, which forces the applicator arms 242 together and locks the clamp 200 closed. Alternatively, the clamps 200 may be applied by hand.

Figure 21 depicts a clamp dispenser 260 for dispensing the clamps 200 depicted in Figure 17. A glued stack of the clamps 200 are loaded into the dispenser 260 and facilitate loading of the clamp 200 onto the applicator 240 depicted in Figures 20A and IR:\LIBLL] 18604.doc:lzv 16 Referring now to Figure 22, the breech region of a sheep is shown with the clamp depicted in Figure 19 applied to the tail of the sheep and the clamp depicted in Figure 17 applied on each side of the sheep's perineum.

Clearly, many variations may be made to the above described embodiments without departing from the scope of the invention. The skilled person will realize that the invention may be embodied in other forms without departing from the scope of the present invention.

[R:\LIBLL]18604 doclzv

Claims (21)

1. A method of treating the breech region of a sheep, said method comprising: providing a clamp having opposing elongate jaws; applying the clamp to a fold of skin in the breech region with a clamping force between the elongate jaws sufficient to substantially starve the fold of skin of blood supply; maintaining the clamp in place until the fold of skin atrophies.

2. The method of claim 1 further comprising maintaining the clamp in place until the atrophied fold of skin becomes detached from and falls off the sheep together with the clamp.

3. The method of claim 1 or 2 wherein the clamp is applied such that a substantially constant clamping force is applied to the fold of skin along its length.

4. The method of any one of the preceding claims wherein the clamping force between the elongate jaws of the clamp is sufficient to completely cut off blood supply to the fold of skin, without cutting through the skin. The method of any one of the preceding claims wherein the clamp is maintained in place for at least 48 hours.

6. The method of claim 5 wherein the clamp is maintained in place for at least 72 hours.

7. The method of any one of the preceding claims wherein the clamp is maintained in place until the skin on the sheep's body immediately adjacent the clamp welds together, such that an open wound does not result when the atrophied fold of skin and the clamp become detached from the sheep.

8. The method of any one of the preceding claims wherein a plurality of clamps is applied to a plurality of folds of skin in the breech region.

9. The method of claim 8 wherein one of said clamps is applied on each side of the sheep's perineum. The method of claim 9 wherein the folds of skin clamped by the clamps on either side of the perineum extend substantially vertically.

11. The method of any one of claims 8 to 10 wherein one or more clamps are applied above and/or below the perineum.

12. The method of claim 11 wherein at least one of the clamps is applied to the tail of the sheep. [R:\LIBLLJI8604.doc:zv 18 IN 13. The method of claim 12 wherein the clamp applied to the tail of the Ssheep clamps a fold of skin adjacent where the tail of the sheep joins the perineum of the (,i sheep. 0 Z 14. The method of any one of the preceding claims wherein an applicator is used to apply the clamp to the fold of skin. The method of claim 14 wherein applying the clamp to a fold of skin t comprises: receiving the clamp in the applicator; opening the clamp with the applicator; 1 0 placing a fold of skin between the opposing edges of the open clamp; closing the clamp with the applicator such that the clamp is locked closed; and removing the applicator from the clamp.

16. The method of claim 15 wherein the clamp is received in the applicator from a clamp dispenser. is 17. A clamp adapted to clamp a fold of skin in the breech region of a sheep, the clamp having: a pair of opposing elongate jaws, each jaw having a clamping edge; and a locking mechanism adapted to lock the two jaws in a closed configuration, wherein the clamping edges are substantially adjacent and opposing one another; wherein the clamp is sufficiently resilient to be locked in the closed configuration with the fold of skin clamped between the clamping edges and to apply a clamping force sufficient to substantially starve the fold of skin of blood supply; and wherein end portions of at least one clamping edge are supported by resilient supports to allow resilient deformation of the at least one clamping edge.

18. The clamp of claim 17 wherein the resilient supports are spring supports.

19. The clamp of claim 17 or 18 wherein the elongate jaws are provided with transverse ridges extending generally normally to the clamping edges, said ridges being adapted to engage the fold of skin and substantially prevent longitudinal sliding of the clamp relative to the fold of skin. The clamp of claim 19 wherein the jaws are provided with a single said ridge on one jaw and a pair of said ridges on the opposing jaw, wherein the single ridge is longitudinally spaced between the pair of ridges on the opposing jaw. AH21(3896991 DOC) I21. The clamp of any one of claims 17 to 20 wherein the clamp has an inner 0 Ssurface for placing against the body of a sheep and an opposite outer surface and wherein the ends of the clamping edges curve outwardly towards the outer surface of the clamp to O resist sliding movement of the fold of skin over the end of the clamping edges.

22. The clamp of any one of claims 17 to 21 wherein the clamp has an inner surface for placing against the body of a sheep and an opposite outer surface and wherein t the clamp is curved with a concave inner surface and a convex outer surface, to generally conform to the shape of the breech region of the sheep. (,i

23. The clamp of any one of claims 17 to 22, wherein the clamp is adapted D o10 to maintain the clamping force for a period of time sufficient for the fold of skin to Satrophy and/or for the skin on the sheep's body immediately adjacent the clamp to weld together.

24. The clamp of any one of claims 17 to 23, wherein the elongate jaws have a length of between 5cm and

25. The clamp of any one of claims 17 to 24, wherein the elongate jaws are pivotally joined at a fixed end of the clamp and the locking mechanism is provided at an opposite free end of the clamp.

26. The clamp of claim 25 wherein the locking mechanism comprises a pair of opposing hooks, one on each elongate jaw, said hooks adapted to resiliently deform and engage one another when the elongate jaws are pressed together at the free end of the clamp, to lock the free end of the clamp in the closed configuration.

27. The clamp of claim 25 or 26 wherein the clamping edges are curved at the fixed end of the clamp.

28. The clamp of any one of claims 25 to 27 wherein the clamp has two lateral elongate jaws and a central elongate jaw forming two pairs of opposing elongate jaws with the central jaw common to the two pairs.

29. A method of treating the breech region of a sheep, said method being substantially as hereinbefore described with reference to any one embodiment, as that embodiment is depicted in the accompanying drawings. R:\LIBLL] 19054doc:Izv I 30. A clamp adapted to clamp a fold of skin in the breech region of a sheep, Ssaid clamp being substantially as hereinbefore described with reference to any one embodiment, as that embodiment is depicted in the accompanying drawings. 0 Dated 9 October, 2006 Australian Wool Innovation Limited Patent Attorneys for the Applicant/Nominated Person In SPRUSON FERGUSON [R:\LIBLL]19054.doc lzv