AU2015215923A1 - Apparatus and process for modifying animal skin by application of cryogenic material - Google Patents

Abstract

Apparatus (30) for tautening the skin of an animal by reducing the size of a skin fold on the animal, including clamping means (42) for clamping the skin fold of the animal and adapted to apply a cryogenic material or agent to the skin of the animal within the confines of the clamping 5 means (42); conduit means (34) for supplying the cryogenic material to the clamping means (42); and control means (37) for controlling the supply of cryogenic material to the clamping means (42), wherein the skin surrounding the processed area of skin contracts or tautens and the area of skin has a reduced or eliminated skin fold through the resultant skin necrosis and absorption via an eschar formation on the processed area of skin. -- 1 - ji------

Description

EDITORIAL NOTE 2015215923 - There are 14 pages of Description - The page numbering starts at "2" APPARATUS AND PROCESS FOR MODIFYING ANIMAL SKIN BY APPLICATION OF CRYOGENIC MATERIAL Field of the Invention 5 The present invention relates to an apparatus and a method of applying cryogenic material to an animal and to a device for positioning an animal to assist in applying such a method. More particularly the present invention relates to a method of applying cryogenic material to an animal in a particular position in order to tighten skin or reduce skin folds. Background of the Invention to Animals such as sheep and in particular merino sheep, are commonly bred in Australia and New Zealand for their high quality wool. However a trait of merino sheep is their loose skin which can result in the presence of skin wrinkles or skin folds. Figure I shows the presence of tail and breech wrinkles 4 which are present at the rear of sheep 2. These wrinkles or skin folds 4, such as the region of skin bounded by lines 6 and 8 in Figure 2 can create a warm and moist L5 protected environment which, given their close proximity to the sheep's perineum, are susceptible to soilage by the sheep's urine and faces, therefore forming a suitable breeding ground for female flies to lay their eggs. Once the eggs hatch the larvae infest the sheep's skin causing skin necrosis and lesions which can become infected and ultimately lead to the death of the animal, if left untreated. This process is known as fly-strike or cutaneous myiasis and is 20 particularly prevalent in Australia given the presence of the primary fly-strike in association with hot and humid conditions as well as the predisposition of merino sheep with wrinkly skin. A technique commonly used to overcome this problem is known as mulesing whereby four areas of skin about the tail and the back of hind legs of a sheep are cut open without anaesthetic in order to remove skin and reduce wrinkles in areas which are susceptible to 25 cutaneous myiasis. Typically the sheep is placed on its back, either with or without a frame, and its hind legs are pushed backwardly to an extent that the skin around the perineum is stretched which makes the skin excessively tight to make it easier for an operator to cut open the areas of skin and reduce the wrinkles. However this causes considerable pain to the animal and predisposes the area to infection. The area also undergoes a slow healing process and is a 30 technique which is strongly opposed by animal rights groups. 2 The present invention seeks to overcome these problems and provide a less painful method of tightening the skin of a sheep. For sheep a more natural position of the sheep is desirable so that the sheep is less stressed and the operator who applies the cryogenic material to the rear portion of the sheep is able to do so in a standing position and have unhindered and full 5 access to the sheep. This natural position also allows an operator to assess the amount of looseness in the skin of the sheep and with the skin in a natural loose position it is easier to apply clamps to the skin in order to apply the cryogenic material to the skin. Traditional cradles thus far have usually had the sheep in either an upright position or on its back with legs stretched that presents the taut or tightened skin. 10 Another problem with merino sheep in particular is the formation of dags at the end of the tail and in the breech area. These are areas of grown wool that can be susceptible to infection as it can provide a suitable breeding ground for flies to lay eggs due to the soiled nature of the dag over time. Summary of the Invention 15 According to a first aspect of the invention there is provided apparatus for tautening the skin of an animal by reducing the size of a skin fold on the animal, including: clamping means for clamping the skin fold of the animal and adapted to apply a cryogenic material or agent to the skin of the animal within the confines of the clamping means; conduit means for supplying the cryogenic material to the clamping means; and 20 control means for controlling the supply of cryogenic material to the clamping means; wherein the skin surrounding the processed area of skin contracts or tautens and the area of skin has a reduced or eliminated skin fold through the resultant skin necrosis and absorption via an eschar formation on the processed area of skin According to a second aspect of the invention there is provided a method of tautening the 25 skin of an animal by reducing the size of a skin fold on the animal, the method including: clamping the skin fold with clamping means to present an area of skin to be processed; supplying cryogenic material through a system of conduits to the skin fold; applying the cryogenic material from the clamping means for a predetermined period of time to each side of the skin fold; 3 so that the skin surrounding the processed area of skin contracts or tautens and the area of skin has a reduced or eliminated skin fold through the resultant skin necrosis and absorption via an eschar formation on the processed area of skin According to a third aspect of the invention there is provided a device for holding and 5 positioning an animal to be processed including: a frame; a pair of angled members secured to the frame and defining a first opening into which the animal is positioned and restrained; wherein the device is attached to a further frame so that the device is raised above the 10 ground thereby providing access to the restrained animal. According to a fourth aspect of the invention, there is provided a device for holding and positioning an animal to be processed that holds a single animal in an upright natural position and is restrained by the shape of the device. The freezing agent/cryogenic material may be sprayed on to the skin for between 5 and 60 seconds. More specifically, the freezing agent may 15 be sprayed on to the skin for between 5 and 30 seconds. According to a fifth aspect of the invention, there is provided a device for holding and positioning an animal to be processed that holds a single animal in an upright natural position and restrained by the shape of the device and wherein the hind legs of the animal are restrained. The animal may be a pig and the processing preferably includes trimming of feet of the pig. 20 According to an embodiment of the invention there is provided a method of tautening skin comprising freezing the skin. The epidermal and dermal layers of the skin may be frozen. The method may reduce wrinkles or skin folds of the skin through subsequent skin necrosis or contraction and eschar formation on the processed skin area. The method may increase the skin tension or tautness. For the purpose of this specification skin wrinkles and skin folds are 25 interchangeable terminologies. These terminologies are used within the sheep industry to describe the result of skin looseness. Freezing the skin may comprise causing intracellular ice or crystal formation in the skin. This may lead to irreversible damage of the skin through cellular necrosis. Thus, the or some of the skin may contract, through necrosis and then form an eschar. The scab formed is usually 30 linear and the surrounding skin is contracted to form a linear scar, replacing the originally cryogenically processed skin. 4 Freezing the skin may cause damage to the collagen layer of the dermis. Scarring may result. This may lead to contraction of the skin. Freezing the skin may comprise achieving a temperature of less than 0 ( zero) degrees Celsius in the skin. More particularly, the temperature achieved in the skin may be less than 5 minus 25 degrees Celsius. Even more particularly, the temperature may be less than minus 50 degrees Celsius. The processed skin may feel solid when the freezing agent is applied. Optimally, the temperature in the skin is between minus 30 degrees Celsius and minus 80 degrees Celsius, with an optimal average of minus 50 degrees Celsius. Freezing the skin may comprise applying a freezing agent or cryogenic material to the [O skin of the animal. The freezing agent may be at a temperature less than minus 5 degrees Celsius. More particularly, the temperature of the freezing agent may be less than minus 60 degrees Celsius. Even more particularly, the temperature may be less minus 190 degrees Celsius. The freezing agent may be applied topically. The freezing agent may comprise a [5 cryogen. The cryogen may comprise liquid nitrogen or liquid oxygen or a combination of liquid nitrogen and liquid oxygen. However, extreme caution must be applied when using solely oxygen as a cryogen due to its severe oxidising effects. The freezing agent may be applied by spraying on to the skin of the animal and may comprise a mixture of aqueous and gaseous cryogen. The region of skin to be processed may extend along the back of the hind leg and lateral or substantially parallel to the sheep's perineum. This region may be called the breech region. The region of skin to be processed may extend along the lateral and end aspect of the tail which hangs posterior to the sheep's perineum. This region may be called the tail region. Wrinkles may be reduced in the region of the processed skin. Additionally wrinkles may 25 be reduced in the area of skin surrounding the region of skin processed. The area of surrounding skin in which wrinkles may be reduced may extend up to 100mm beyond the region of skin processed. Suitably, it may extend up to 50mm beyond the region of skin processed. The method may be bloodless. The method may be non-invasive. The method may comprise shielding the skin around the region of skin to which the freezing agent is to be 30 applied. The method may comprise clipping hair which covers the skin prior to applying the freezing agent. The hair may comprise wool. The resultant wound is closed, that is, the skin 5 covers the targetted area. The wound is therefore not susceptible to infection or fly-strike during healing. The method may comprise spraying the freezing agent onto the skin through variable lengths of wool. 5 The method may comprise clamping the wrinkle of skin prior to applying the freezing agent. The method may comprise spraying the freezing agent at a rate of at least 5 grams per minute. More specifically, the rate may be at least 50 grams per minute. Even more specifically, the rate may be at least 140 grams per minute. In a preferred embodiment the freezing agent of 10 cryogenic material is sprayed at a rate of up to 2kgs per minutes or more, such as up to 500gms per area of four areas to be sprayed at the rear of the sheep (tail and breech regions). The method may comprise spraying the freezing agent on to the skin for between 5 and 60 seconds. More specifically, the freezing agent may be sprayed on to the skin for between 5 and 30 seconds and preferably for 1-3 seconds for each clamped aspect of skin. 15 The cryogen may be in part liquid and part vapour form as it contacts the skin, but preferably mostly a liquid component. The freezing agent may be sprayed continuously on to the skin. The method may comprise allowing the skin to thaw before reapplying the freezing agent. The skin may be allowed to thaw for 15 to 60 seconds. Suitably, the skin may be allowed 20 to thaw for between two and three minutes. The freezing agent may be reapplied immediately or some time after the initial application, especially if skin solidity is not achieved sufficiently. The freezing agent may be sprayed between 0.5 and 10 cm away from the skin. More particularly, the freezing agent may be sprayed between 2 and 4 cm away from the skin. The freezing agent may be sprayed or applied through spray means, such as spray bars, contained 25 within the clamping means. The skin may be animal skin. More particularly it may be sheep skin. The sheep may be of the Merino type. Suitably, it may be a lamb, weaner, or older sheep. The sheep may generally be between 1 week and 18 months of age when presented for processing. The method may be used to process animals en masse. It may be used in conjunction, 30 and without interfering, with normal animal husbandry procedures. 6 In another aspect the invention provides a method of reducing or removing skin, wrinkles or both comprising freezing the skin. The wrinkles may be reduced by tautening of the skin which may occur following freezing. The degree of tautening may depend on the area of skin processed. An increase in the 5 skin area applied with cryogen, may result in an increase of surrounding skin tautening. Sheep with loose skin have increased predisposition to fly strike. These animals generally have more skin wrinkles. Skin wrinkles may be significantly reduced when an appropriate skin area is processed. Brief Description of the Drawings 10 Preferred embodiments of the invention will hereinafter be described, by way of example only, with reference to the drawing in which: Figure 1 is a rear view of a sheep with skin folds prior to cryogenic application; Figure 2 is a rear view of the sheep of Figure 1 and shows areas of skin processed; Figure 3 is a block diagram of apparatus used to apply a cryogenic material to an animal 15 to remove skin folds; Figure 4 is a block diagram of further apparatus that can be used in addition to the apparatus of Figure 3; Figure 4A is a block diagram of a further embodiment of apparatus that can be used in place of the apparatus of Figure 3; 20 Figure 5 shows respectively plan and side views of a manifold arrangement for connecting hoses or tubes supplying the cryogenic material; Figures 6A and 6B show side and perspective views respectively of a clamping tool and an alternative blade arrangement for clamping the skin of an animal to be processed; Figure 7 is a side sectional view of the outer layers of the skin of the animal with the 25 clamping tool of Figure 6 applied to a skin fold such that the epidermis and dermis is clamped ready for processing; Figure 8 is a view of the apparatus and a holding device or cradle ready for use; 7 Figure 9 is a view showing a sheep being loaded into the holding device prior to processing; Figure 10 is a view showing an upright rotatable support structure for the animal for use in cryogenic processing; 5 Figure I is a further view showing the animal positioned in the holding device angled slightly forward; Figure I1 A is a view showing an alternative holding device having a front safety bar and a member adapted to press against the animal's back when undergoing processing; Figure 12 is a view showing the animal in a secured position with hind legs restrained for 10 the process; Figure 13 is a view of the animal in Figure 12 with clamping tools attached to areas of the animal for ready to be processed; Figure 14 is a view similar to Figure 13 showing the held sheep from a different angle; Figure 15 is a more magnified view of Figure 14; 15 Figure 16 is a wider view of Figure 14 showing a support arrangement for the clamping tools and associated tubes and a control means' Figure 17 is a view of an alternative embodiment of apparatus used to cryogenically process an animal, in this case cattle, to remove horns or horn buds; Figure 18 is a rear view of the sheep of Figure 1 approximately two weeks post 20 processing; Figure 19 is a rear view of the sheep of Figure 1 approximately four to six weeks post processing; Figure 20 is a table showing the degree of wrinkliness of a sample of sheep before and after applying the method of the invention 25 8 Detailed Description of the Preferred Embodiments Referring to Figures 1 and 2, there is shown hind legs 18 and tail 20 of an animal such as a merino lamb, generally designated by number 2. It has extensive breech and tail skin wrinkles 4. Breech and tail regions, shown by outlines at 6 and 8 respectively, represent areas of skin to 5 which a cryogenic material, such as liquid nitrogen, is to be applied during cryogenic processing. The breech region 6 extends separately along both sides along the upper hind legs, adjacent to the tail 20 and lateral or parallel to the perineum. Each breech region 6 is approximately 150mm long and 35mm wide. Due to the close proximity to the perineum, the breech region 6 is prone to being soiled by urine and faeces which leaves wrinkles in the area [0 susceptible to cutaneous myiasis. The area of processing varies according to the animal's age and animal type and their respective degrees of wrinkliness. The tail regions 8 extend laterally on opposite sides along the upper aspect of the tail 20, posterior to the perineum when the tail hangs down. Each tail region 8 is about 85mm long and 25mm wide and its closeness to the perineum also leaves it susceptible to soilage by the sheep's L5 urine and faeces. This again can lead to cutaneous myiasis in the tail region 8. A further region 19 exists at the end of the tail from which dags can develop. This is also required to be processed using a cryogenic material. Typically the cryogenic material is applied directly to the wool and not against the bare skin of the animal. The wool insulates the animal to a certain degree during the cryogenic application and buffers or cushions the liquid nitrogen from .0 contacting the skin. Eventually the wool along the affected regions shrinks and develops into an eschar that forns after a few weeks. Referring to Figure 3 there is shown a block diagram of apparatus 30 that is used to apply cryogenic material, such as liquid nitrogen, to the rear parts of a sheep and more particularly a merino sheep. The apparatus 30 includes container 32 which houses liquid nitrogen and can 25 have a volume of up to 400 litres and be portably mounted to a trailer so that the container 32 can be used on various properties. The liquid nitrogen is generally kept under pressure in the range 35psi to 100psi and most preferably in the range 40psi to 90psi, and this can be regulated through controls and a gauge showing the pressure inside the container 32. A vacuum sealed conduit in the form of a hose 34, that is generally up to 10 metres long, made from a light 30 durable material, such as aluminium, is insulated so that it defines an interior channel through which liquid nitrogen is dispensed from the container 32. If pressure increases to a significant level within the container 32, a gas release valve 36 is positioned in the hose 34 to relieve any 9 excess build-up of gas. At the other end of the hose 34 there is connected a control means 37 in the form of a valve or solenoid. From the output of the solenoid 37 it branches out into a pair of separate conduits or hoses 34A and 34B similar in design and structure to conduit or hose 34 either emanating directly from the output of the solenoid or from a separate T-piece 38. A first 5 manifold arrangement 40 is connected at the outer part of hose 34A which leads directly to first and second pairs of skin clamps 42 and 44 which are connected through respective conduits or hoses 46, 47 and 48, 49 to the first manifold section 40. Similarly at the end of hose 34B there is provided a second manifold section 50 which has extending therefrom conduits or hoses 52, 53 and 54, 55 that respectively tenninate in a further pair of skin clamps 56 and 58. One pair of 10 skin clamps, such as 42 and 44 are clamped to portions of the tail at regions 8 while the other pair of skin clamps 56 and 58 are applied to the breach regions 6 either side of the perineum. Control of the valve or control means 37 is supplied by a pedal device 60 operated by the operator's foot so that depressing the foot pedal 60 releases or opens up the valve 37 to allow liquid nitrogen to flow through each of hoses 34A and 34B and eventually hoses 46 to 54. As an [5 additional option a further solenoid or control means 62 can be placed in parallel with the control valve 37 to allow an additional pair of conduits or hoses 63, 64 (or 73, 75) to be connected to a further clamp 66 ( or 71) which can be applied to the tail end section transversely of the perineum and transversely compared to the other tail regions 8. This is generally only used where insufficient liquid nitrogen from the other clamps on the breech regions and the tail !o regions has not extended to the end of the tail. Again this can be foot operated through the pedal 60. Each clamp has two nozzles, in the form of a rod with apertures, one rod for each blade of the clamp and hence there are two hoses/hoses for each clamp supplying the liquid nitrogen. Hose 79 is connected to one side of T-picee or manifold 77, which in turn connects to each of the conduits 63, 64, 73 and 75. 25 Shown in Figure 4 there is a slight alternative to that shown in Figure 3 where solenoid 62 is directly connected to a further container 68 and by conduit or hose 65. The container 68 has a smaller volume than container 32 and is generally up to 50 litres (volume range from 5 litres to 150 litres) in volume having the same pressure range 35psi to 1 00psi as container 32. In this manner a ready supply of liquid nitrogen can be applied to the end of the sheep's tail through 30 clamp 66 and hoses 67, 69 when required. Again this will only be required when the end part of tail has not been frozen enough in order to make the liquid nitrogen effective against the growth of 1 ool which turns into dags. 10 In Figure 4A, there is shown a further variation to the arrangements of Figures 3 and 4, in which a clamp is connected directly to a solenoid valve 37, that can be controlled by foot pedal ) 60. Either a single hose 46, that can be joined in lengths and is double-evacuated/insulated, can connect between a solenoid 37 and clamp 42 or a pair of hoses 48, 49 can connect from another 5 solenoid 37 to respective nozzles in clamp 44. The pair of solenoid valves is linked to a T intersection 61 which in turn is connected to container 32 through conduit 34. A gas release valve can be positioned in conduit 34. Referring to Figures 5 and 6, each of the manifolds 40 and 50 includes a first portion 70 and a second portion 72 which are respectively at an acute angle to one another and attached to 10 bar 74. On an opposite side of the bar 74 there is connected hoses 34A or 34B through a suitable connector. Each of the portions 70 and 72 are angled to one another to provide enough space for the hoses depending from them and to provide a better angle of connection of the hoses to the clamps. Each portion 70 and 72 has two connectors for respective attachment to a pair of hoses. Each pair of hoses leads to a skin clamp, for example, hoses 46 and 47 lead to skin clamp 42 15 which connect to nozzles or rods located oppositely on the inside surface of clamp shields of a respective clamp (as seen in Figures 6A and 6B). Thus for example hoses 46 and 47 respectively connect to the nozzle 76 and 78 which are located on inside faces of clamp shields or blades 80 and 82. The clamp shields 80 and 82 are opened and closed through handles 84 and 86 which are connected through a spring element 88. Clamp shield lengths vary and for larger sheep are 20 120mm long and for smaller sheep, such as lambs, are approximately 90mm in length. The clamp shield ends can be covered or partially sealed to stop oversupply or spilling of the liquid nitrogen. Smaller shields 90, 92 as seen in Figure 6A can be used for smaller animals such as lambs so that not too much skin is folded between the shields. Shields 80 and 82 are larger which can be used for ewes or weaners. Each of the nozzles 76 and 78 have a series of 25 apertures, typically 3 to 5 per rod of the nozzle where there are two bars per clamp and each hole typically has an aperture of 1.2mm to 1.5mm. The skin clamps are typically 120mm to 80mm in length. As mentioned previously a pair of skin clamps, for example 42 and 44 are attached to breach regions 6 of the rear part of a sheep while clamps 56 and 58 are attached to the edge of the tail sections 8. Generally the clamps are clamped at the edge of the bare skin of the tail at the 30 junction of the bare skin and the tail wool. Liquid nitrogen is then supplied to the breech and tail regions 6 and 8 for a set period of time while the animal is contained within a support or cradle to be discussed hereinafter. 11i Referring to Figure 7 there is shown a cross-section of the animal's skin, subcutaneous tissue and muscle. The ends of the clamp shields 80 and 82 clamp a section of skin or a skin fold 93 ready for processing via the application of liquid and gaseous nitrogen. The skinfold 93 which has been clamped only contains the epidermis 94 and dermis layer 96, which is the 5 complete depth of skin and this is why there is minimal pain to the animal. This is so that the complete epidermis layer and the dermis layer of the processed skin is fully processed and has undergone the freezing process, and provides a significant decrease in skin folds over time. Upon application of the liquid nitrogen through the apertures of each of the nozzle rods, for example 76 and 78, whereby liquid nitrogen is applied from both sides of the skin fold 93, the 10 skin right through to the centre of the skin fold 93 is frozen at an optimal temperature between 60* C and -80" C. Pinching isolates the skin from the subcutaneous layer and prevents any harmful destruction of the subcutaneous layer. When frozen, the cells produce large ice crystals particularly at around -60" C and thereafter undergo cellular lysis. This is termed cellular lysis after the ice crystals form and melt from exposure to the liquid and gaseous nitrogen. 15 Referring to Figure 8 there is shown the apparatus 30 ready to use on an animal, such as a sheep, which will be placed in holding device or cradle 100. The cradle 100 can be one of a number of such cradles that are attached to a support structure or an upright stand 102 which is able to be rotated, akin to a merry-go-round. With the apparatus of Figures 4A and 8, it is possible to process up to 500 lambs a day, or about 80 lambs per hour. ?0 Referring to Figure 9 there is shown a sheep being unloaded from a conveyor belt device 110 into the cradle 100. This method of automatic loading is possible through the upright cradle design and the cradle having an adjustable open gap at the base of the cradle. It is used to alleviate the usually heavy lifting of sheep by operators. Referring also to Figures 10, 11, 11 A, 12 and 13, the holding and positioning device or 25 cradle 100 is made up of a frame 112 which is connected to member 114 which in turn is connected to a bar 115 connecting another member 114 on the other side of the frame 112. A pair of angled bars 116 lead upwardly to the member 114 on both sides of the frame 112 whilst substantially vertical bars 118, with respect to horizontal bar 115, form the support for a pair of angled members 120, which can either be made of an integral planar material or include a series 30 of rollers 122. The reason for the rollers 122 on each angled side 120 is so that when the sheep is unloaded from the conveyor belt 110 it is continually moved by the rollers 122 to be positioned correctly within the cradle 100 so that the sheep's forelegs hang down from the front of the cradle 100 while its rear legs hang down from the back of the cradle 100. The rollers 122 12 may be covered with a conveyor belt so the rollers and belting case the movement of the sheep into and from the cradle 100. The rear legs of the animal are secured through locking devices 121 which are essentially U-shaped rods that protrude in and out of member 123 of the frame 100 and are locked through a handle 124 above the hocks of the sheep. In this way the sheep 5 will not be able to bend its rear legs and try and work free from the cradle 100. The cradle 100 is angled downwardly generally, as is more clearly seen in Figures 10 and 11, and this prevents the sheep from wanting to pull out backwardly from the cradle 100. At the front of the cradle 100, there is positioned two bars 126 that can have fitted to it a soft tubular structure, typically up to 4" in diameter, so that it abuts against the sheep's chest and prevents it from falling out of the 10 front of the cradle 100. As seen in 1 A, there is a member 128 which is adjustable between a non-used position and a used position. When the sheep is fully positioned in the cradle 100, the member 128 is brought into engagement with the back of the sheep to keep the sheep in position and prevent it from moving upwardly. As mentioned previously, the bar I15 which joins each of the members 114 is in turn 15 affixed to an arm 130 of the upright frame 102. As seen in Figure 10 there are four such arms 130 which each have depending therefrom or can have depending therefrom a cradle 100. This allows up to four sheep or animals to be worked on using the apparatus 30 for, not only processing the rear portion of the sheep with cryogenic material to reduce skin folds, but also to process sheep for vaccinations, castration of male sheep, lamb marking and tail stripping if 20 required, and be rotated to desired positions through the upright frame 102. Referring to Figures 13, 14, 15 and 16, there is shown a sheep in a natural position where skin folds would not be in a taut state but in their own natural, loose state. Figure 13 shows the various clamps fitted to the tail section 8 and breech sections 6 of the rear of the sheep. In this particular embodiment, the shields of the clamp show a slight opening at the top and also at each 25 end where nitrogen gas can escape. Other embodiments seek to close these gaps and therefore retain as much nitrogen gas within the confines of the skin fold so that eventually less nitrogen is used for the intended application. Thus additional padding/covers may be inserted on the inside surface of each shield without impeding the nozzle(s), so that when they are closed around a skin fold there are substantially no gaps existing for escape of any cryogenic material. 30 Furthermore, referring to Figure 13 multiple clamps are shown connected to the breech and tail sections of a sheep at just one point (station) out of four points (or stations). However, using the arrangement shown in Figure 4A, one station of apparatus 30 can be used to apply a single clamp (for example clamp 42) with cryogenic material to a sheep for about 1-2 seconds in 13 a number of breech sections that need to be processed (typically 2-6 sections), for example, while another station can be used to apply a further single clamp (for example clamp 44) with ) cryogenic material to a sheep for about 1-2 seconds in a number of tail sections that need to be processed (typically 2-4 sections). This provides a faster and more efficient use of the stand and 5 the apparatus 30. The various hoses and connectors as well as the blades of the clamps are shown as frosted which is due to the effect of the extremely cool liquid nitrogen. Shown in Figures 15 and 16, are support stands 140 and 142 which respectively hold in position the sets of hoses that are attached to the clamps. Each of the support stands 140 and 142 are respectively attached just 10 below the manifold sections 40 and 50. The support stands 140 and 142 better position and hold in place the clamps and associated hoses. Figures 1, 2, 18 and 19 are a sequence of rear views of a sheep 2 at various times before and after cryogenic processing. This single case sequence illustrates the changes in the skin which can occur following cryogenic processing. 15 Referring to Figure 1, there is shown a sheep 2 prior to cryogenic processing. The sheep has generally vertically aligned skin folds 4 present at the rear of the sheep. In particular, there is one pair of skin folds 4 on opposite lateral aspects of the tail 20, and three pairs of generally parallel skin folds 4 along the back of the hind legs 18. Figure 2 shows the sheep 2 of Figure 1 immediately following cryosurgical processing. 20 Outlined breech regions 6 and tail regions 8 represent areas of skin to which liquid nitrogen was applied, with the application of liquid nitrogen causing these areas of skin to be frozen at the time of processing. The areas processed will darken over the first day after processing and then from that time, up to about seven days after, swelling of the skin will occur. Figure 18 shows the sheep 2 of Figure 1 approximately two weeks post processing. As 25 shown, the processed areas of skin (i.e. the breech regions 6 and the tail regions 8) have contracted with resultant scabbing or skin crusts with hardened skin formation, appearing superficially like dry areas of skin with matted wool. Contraction of the skin in the breech and tail regions, 6 and 8 respectively, has resulted in flattening of the skin folds 4 within these regions. Additionally, contraction of the skin in the breech and tail regions 6, 8 has resulted in 30 pulling of the surrounding skin towards the processed area, thereby reducing skin folds 4 in the surrounding skin. This process of contraction and eschar formation generally takes place over 7 to 42 days after processing. 14 Referring to Figure 19, the sheep of Figure 1 is shown approximately four to five weeks post processing. The breech and tail regions of skin, 6 and 8 respectively, have further ) contracted to form longitudinal scars which do not grow wool. In addition, folds in the skin surrounding the breech and tail regions 6, 8 have further reduced with smoothness of the skin 5 being evident in the general areas around the breech and lateral aspects of the tail. Referring to Figure 20, there is a table 150 showing the results of wrinkle measurements of a sample of lambs before and after application of the cryogenic material to the tail and breech sections of lambs. The lambs are identified by tag numbers in column 151. On 9 April 2015 each lamb's tail wrinkle score (TWS) is given in column 152, with a "5" indicating very wrinkly 10 to a "1" indicating a firm skin with very little if any wrinkles, and the breech wrinkle score (BWS) is given in column 153. The breech width in mm is given for each lamb in column 154. About three months later after the application of the method of the present invention, on 7 July 2015, the measurements of the TWS is given in column 155 and the BWS in column 156, with the breech width in column 157. As can be seen the average TWS has reduced from 4.4 to 1.5 15 and the average BWS has reduced from 3.8 to 1.4 in that time span, providing a marked improvement in the reduction of wrinkles. The present invention provides a system, method and apparatus to apply a cryogenic process to animals, particularly merino sheep, that tautens the skin in the breech area by a process of freezing skin, enabling necrosis and eschar formation to occur, with a resultant lineal 20 scar which pulls the skin either side of the scar towards each other to effectively tighten the skin and make the processed sheep a plain skin sheep. It is preferably to use a one clamp system at at least one station of a rotating apparatus to process a lamb, with the rotating apparatus either being manually turned or powered to turn, with each sheep positioned in a cradle. Typically the apparatus is operated by two people and one clamp at each station placed subsequently on the 25 areas of skin to be processed. Different sized clamps can be used depending on the anatomy, conformation and body condition of the animals. 15

Claims (15)

1. Apparatus for tautening the skin of an animal by reducing the size of a skin fold on the animal, including: clamping means for clamping the skin fold of the animal and adapted to apply a 5 cryogenic material or agent to the skin of the animal within the confines of the clamping means; conduit means for supplying the cryogenic material to the clamping means; and control means for controlling the supply of cryogenic material to the clamping means, wherein the skin surrounding the processed area of skin contracts or tautens and the area of skin has a reduced or eliminated skin fold through the resultant skin necrosis and absorption 10 via an eschar formation on the processed area of skin.

2. Apparatus according to claim 1 wherein the clamping means includes one or more clamps for processing separate areas of the skin. 15

3. Apparatus according to claim 2 wherein each clamp has a pair of handles and a pair of shields controllable by manipulating the handles, each shield gripping one side of the skin to be processed.

4. Apparatus according to claim 3 further including nozzle means through which the 20 cryogenic material is dispersed.

5. Apparatus according to claim 4 wherein said nozzle means is positioned on one or more of the shields and has a series of apertures through which the cryogenic material is emitted to process the clamped skin fold. 25

6. Apparatus according to claim 5 wherein the nozzle means is a rod positioned on an interior face of the shield. 16

7. Apparatus according to any one of the previous claims further including a junction in the form of a manifold between a conduit leading to the control means and one or more conduits leading to said clamping means. 5

8. Apparatus according to any one of the previous claims wherein the control means is at least one solenoid valve having one or more conduits at an output leading to said clamping means and input means for receiving the cryogenic material from a cryogenic material source, either immediately proximal to the at least one solenoid valve or at a distance away from the at 10 least one solenoid valve.

9. A method of tautening the skin of an animal by reducing the size of a skin fold on the animal, the method including: clamping the skin fold with clamping means to present an area of skin to be processed; 15 supplying cryogenic material through a system of conduits to the skin fold; applying the cryogenic material from the clamping means for a predetermined period of time to said skin fold; so that the skin surrounding the processed area of skin contracts or tautens and the area of skin has a reduced or eliminated skin fold through the resultant skin necrosis and absorption via 20 an eschar formation on the processed area of skin.

10. A device for holding and positioning an animal to be processed including: a frame; a pair of angled members secured to the frame and defining a first opening into which the 25 animal is positioned and restrained; wherein the device is attached to a further frame so that the device is raised above the ground thereby providing access to the restrained animal. 17

11. A device according to claim 10 wherein each angled member includes a series of rollers to assist in correctly positioning the animal in the device. 5

12. A device according to claim 10 or claim II further including a pair of locking devices for temporarily restraining the hind legs of the animal.

13. A device for holding and positioning an animal to be processed that holds a single animal in an upright natural position and is restrained by the shape of the device. 10

14. A device for holding and positioning an animal to be processed that holds a single animal in an upright natural position and restrained by the shape of the device and wherein the hind legs of the animal are restrained.

15 15. A device according to claim 16 wherein the animal is a pig and the processingincludes trimming of feet of the pig. 18