Abstract:
A device ( 10 ) for receiving and confining an animal, such as a bail, is disclosed. The device ( 10 ) comprises a pen ( 12 ) having at least two elongate walls ( 21, 22 ) spaced apart to define a space into which the animal is received. An entry gate assembly ( 24 ) is located at a first end of the pen ( 12 ) and is movable between an open position, which permits entry of the animal into the pen ( 12 ), and a closed position. An exit gate assembly ( 26 ) is located at a second end of the pen ( 12 ) and movable between an open position, which permits the release of the animal from the pen ( 12 ), and a closed position, which prevents release of the animal from the receiving pen ( 12 ). At least one of the entry gate assembly ( 24 ) and the exit gate assembly ( 26 ) includes a pair of door members ( 30 ), each having a substantially vertically extending planar surface ( 32 ). Each door member ( 30 ) is rotatably mounted to the pen ( 12 ) at the first and/or second end of the pen such that when the gate assembly ( 24, 26 ) is moved to the closed position, the door members ( 30 ) rotate such that their planar surfaces ( 32 ) abut to extend substantially across the first and or second end of the pen ( 12 ), and when the gate assembly ( 24, 26 ) is moved to the open position, the door members ( 30 ) rotate such that their planar surfaces ( 32 ) are located adjacent a respective elongate wall ( 21, 22 ) of the pen ( 12 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a national phase entry under 35 U.S.C. § 371 of International Patent Application PCT/AU2007/000412, filed Mar. 30, 2007, published in English as International Patent Publication WO 2007/112487, which claims priority from Australian Provisional Patent Application No 2006901647 filed on 30 Mar. 2006, the contents of each of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a device for handling livestock and, in particular, to a device that facilitates monitoring and sorting of livestock. 
       BACKGROUND 
       [0003]    In countries such as Australia, the livestock industry contributes greatly to the economical and social wellbeing of the nation. The success of the livestock industry is greatly dependent upon the ability of primary producers, such as farmers, to control and monitor their livestock to ensure an acceptable degree of livestock quality, such that the industry is sustainable. 
         [0004]    With increased demands being placed on primary producers, livestock production and maintenance is a business requiring significant investment in both time and resources. In recent times, with the loosening of various trade restrictions between countries, there has been an increase in competition between livestock producers and suppliers, resulting in a need for farmers and other such primary producers to adopt even more efficient work practices to ensure production of a high quality at a competitive price. 
         [0005]    The beef industry in Australia is one of Australia&#39;s major agricultural industries with about a quarter of the Australian farming establishments deriving their main income from beef cattle farming. The types of farming establishments dedicated to cattle farming varies from intensively managed small holdings in the southeast region of Australia, where water supplies and soil conditions facilitate high stocking rates, to extensive large-scale cattle stations in northern and central parts of Australia, where cattle roam relatively free with minimal regular human contact. 
         [0006]    As discussed above, the need to monitor and assess the growth and health of individual animals is important in order to maintain a competitive and sustainable livestock industry. This is typically performed by gathering the animals and individually assessing them and, where necessary, sorting the animals for further processing. The animals are typically sorted in terms of their weight and/or age, such that they can be made available for slaughter and/or selling/export, thereby providing a source of income to the farmer. As the income is typically dependant upon the health and/or condition of the animal, regular monitoring and assessment of the animal is important to ensure maximum return to the farmer. 
         [0007]    As such, a number of systems have been introduced to assist the farmer in individually monitoring and assessing their livestock. Such systems typically employ a variety of chutes and gates for individually directing the animals in a controlled manner through a variety of devices whereby an individual animal can be isolated from the rest of the animals for assessment and/or treatment. Assessment may include weighing, branding, applying medical treatment, and/or otherwise examining the animal. 
         [0008]    Generally, the chutes are designed to be long and narrow in configuration so as to form an elongate space into which one animal at a time is manually driven. A head gate may be inserted into the chute to prevent the animal from progressing further while a tail gate is driven into the chute behind the animal preventing the animal from backing away from the space, thereby isolating the animal from the other animals for assessment and/or treatment. As will be appreciated, such a manual means of isolating individual animals requires considerable labor that is generally not readily available in remote locations or in instances where the farm is operated by a single farmer with limited assistance. This can also increase farm operating costs due to the need to hire workers to perform such tasks. 
         [0009]    For this reason, automated systems have been proposed that are remotely controlled by an operator to initiate capture of an animal within a confined space. These systems can also be used with various drafting devices to provide the operator with the ability to sort the animals into two or more herds following assessment and/or treatment of the individual animals. A common problem with most existing systems is that they employ sliding of swinging gates to close in front of and behind the animal to capture the animal, which can obstruct the animals as they pass through the chutes of the various systems. Such obstructions can significantly reduce the flow of the animals passing through the chutes, thereby resulting in the need for the operator to intervene to urge the livestock to flow in an orderly manner. This is a particular problem when large volumes of livestock are being assessed and the availability of human assistance is scarce. 
         [0010]    Further, sliding and/or swinging gates have a tendency to tilt and wedge during use, particularly when used with cattle and the like, which have significant weight and apply significant force against the hinges and rails of the gates during use. This can cause the gates to malfunction, thereby requiring repair and/or replacement. Such repair/replacement of the gates can cause significant delays and unnecessary costs to the farmer. Also, most existing gate arrangements swing or otherwise move beyond the livestock handling area or chutes and into the area occupied by the equipment operators. Such moving components can create and pose significant risks to the wellbeing of the operators. 
         [0011]    Therefore, there is a need to provide a livestock handling system that is designed to assist the progress of animals through the system, and that is not prone to malfunction during use, and/or compromise the safety of the operator(s). 
         [0012]    A discussion of documents, act, materials, devices, articles or the like, which has been included in the present specification, is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. 
       SUMMARY OF THE INVENTION 
       [0013]    According to a first aspect, the present invention is a device for receiving and confining an animal comprising:
       a pen having at least two elongate walls spaced apart to define a space into which the animal is received;   an entry gate assembly located at a first end of the pen and movable between an open position, which permits entry of the animal into the pen, and a closed position; and   an exit gate assembly located at a second end of the pen and movable between an open position, which permits the release of the animal from the pen, and a closed position which prevents release of the animal from the receiving pen;   wherein at least one of the entry gate assembly and the exit gate assembly includes a pair of door members each having a substantially vertically extending planar surface, and wherein each door member is rotatably mounted to the pen at the first and/or second end of the pen such that when the gate assembly is moved to the closed position, the door members rotate such that their planar surfaces substantially abut to extend across the first and/or second end of the pen, and when the gate assembly is moved to the open position, the door members rotate such that their planar surfaces are located adjacent a respective elongate wall of the pen.       
 
         [0018]    In one embodiment, when the gate assembly is moved to the open position, the door members rotate such that their planar surfaces are substantially parallel to the respective elongate walls of the pen. In another embodiment, when the gate assembly is moved to the closed position, the door members rotate such that their planar surfaces extend substantially orthogonal to the elongate walls of the pen. 
         [0019]    The planar surfaces of each door member may comprise a panel extending between a pair of plates. The plates may be rotatably mounted to the pen such that each door member is able to rotate about a vertical axis. 
         [0020]    An elongate roller member may be mounted between the pair of plates so as to extend along an edge of the panel. The edge of the panel may be a distal edge of the planar surface. The elongate roller member may be free to rotate about its vertical axis. 
         [0021]    In another embodiment, each door member is rotated between the open and closed positions by a linear actuator connected to at least one of the plates. Reciprocal movement of the linear actuator may cause the door member to rotate about its vertical axis between the open and closed positions. The linear actuator may be a pneumatic ram that is controlled by a control system to provide remote control of either or both of the entry and exit gate assembly. In another form, the linear actuator may be manually operated. 
         [0022]    In yet another embodiment, the space into which the animal is received is adjustable to accommodate a wide variety of animal types and sizes. In one form, one or more of the at least two elongate walls of the pen may be moveable to alter the size of the space. In this regard, one or more of the at least two elongate walls of the pen may be inwardly pivotal. 
         [0023]    According to a second aspect of the present invention, the present invention provides a gate assembly for a pen for receiving and confining an animal, comprising:
       a pair of door members rotatably mounted to the pen so as to independently rotate about a vertical axis, each door member having a substantially vertically extending planar surface; and   a linear actuator mounted to the pen so as to be in connection with the pair of door members;   wherein actuation of the linear actuator in a first direction causes the pair of door members to rotate such that their planar surfaces extend substantially orthogonal to a direction of travel of the animal so as to close an opening of the pen, and actuation of the linear actuator in a second direction causes the pair of door members to rotate such that their planar surfaces are located substantially parallel to the direction of travel of the animal so as to open an opening of the pen.       
 
         [0027]    According to an embodiment of this aspect of the invention, the planar surfaces of each door member comprise a panel extending between a pair of plates. The plates may be rotatably mounted to the pen such that each door member is able to rotate about a vertical axis. 
         [0028]    An elongate roller member may be mounted between the pair of plates so as to extend along an edge of the panel. The edge of the panel may be a distal edge of the planar surface. 
         [0029]    According to a third aspect, the present invention is a livestock receiving device for receiving and confining an animal compromising:
       at least two side walls spaced apart to define an elongate receiving space into which the animal is received;   an entry gate assembly located at a first end of the receiving space and movable between an open position, which permits entry of the animal into the receiving space, and a closed position, which prevents entry of the animal into the receiving space; and   an exit gate assembly located at a second end of the receiving space and movable between an open position, which permits the release of the animal from the receiving space, and a closed position, which prevents release of the animal from the receiving space;   wherein at least one of the entry gate assembly and the exit gate assembly includes at least one vertically extending gate member that is rotated between the open position and the closed position such that movement of at least one gate member does not extend beyond a perimeter of the device.       
 
         [0034]    In one embodiment of this aspect of the invention, at least one of the entry gate assembly and the exit gate assembly comprises a pair of vertically extending gate members arranged proximal the side walls of the receiving space. Each of the gate members may be configured such that when they are in the open position, they are substantially parallel to the side walls along each side of the receiving space, and when they are in the closed position, they extend substantially orthogonal to the side walls. 
         [0035]    Each gate member may comprise a panel extending between a pair of plates. The plates may be mounted to the device such that the gate member is able to rotate about a vertical axis, thereby moving the panel between an open position where the panel is substantially parallel to the side walls and a closed position where the panel extends substantially orthogonal to the side walls. A roller member may extend along an edge of the panel. The edge of the panel may be a leading edge of the panel; namely the outermost edge of the panel when the panel is rotated to the closed position. The roller member may be mounted between the plates such that it is free to rotate about a vertical axis. In this arrangement, the roller member may contact the animal as the gate member opens and/or closes, such that the gate member is able to ride over the animal. 
         [0036]    The gate member may be rotated between the open and closed positions by a linear actuator connected to at least one of the plates. Reciprocal movement of the linear actuator may cause the gate member to rotate about its vertical axis between the open and closed position. In one form, the linear actuator may be a pneumatic ram, which is controlled by a control system to provide remote control of either or both of the entry and exit gate assemblies. In another form, the linear actuator may be manually operated. 
         [0037]    In another embodiment, the receiving space may be provided with a weighing scale to obtain the weight of the animal received within the receiving space. In this arrangement, the device may comprise an electronic reading device to read an identification tag of an animal, such as an ear tag or an electronic chip implanted under the animal&#39;s skin, to identify the animal such that the obtained weight can be stored against the animal. A control system may store the obtained weight data with the animal to facilitate sorting of the animals into desired groups upon leaving the receiving space. In this regard, a sorting or drafting device may be arranged proximal the exit gate assembly and controlled by the control system to sort the animal upon exiting the receiving space. 
         [0038]    In another embodiment, the receiving space may be adjustable to accommodate a wide variety of animal types and sizes. In this regard, one or more of the at least two side walls may be moveable to alter the size of the receiving space. A locking means may be provided to lock the side walls in one of a variety of positions, according to the size and/or type of animal being handled. 
         [0039]    According to a fourth aspect, the present invention is a livestock receiving device for receiving and confining an animal comprising:
       at least two side walls spaced apart to define an elongate receiving space into which the animal is received;   an entry gate assembly located at a first end of the receiving space and movable between an open position, which permits entry of the animals into the receiving space, and a closed position, which prevents entry of the animal into the receiving space; and   an exit gate assembly located at a second end of the receiving space and movable between an open position, which permits the release of the animal from the receiving space, and a closed position, which prevents release of the animal from the receiving space;   wherein at least one of the side walls is movable with respect to another of the side walls so that the elongate receiving space can be altered to receive animals of varying sizes.       
 
         [0044]    According to a fifth aspect, the present invention is a gate assembly for a livestock handling device comprising:
       a vertically extending panel mounted between a pair of mounting plates;   an elongate roller arranged to extend along an edge of the panel between the plates and being free to rotate about its axis;   wherein the mounting plates are configured to be mounted to the device such that the panel and roller can rotate between an open and closed position.       
 
         [0048]    Throughout this specification the word “comprise,” or variations such as “comprises” or “comprising,” will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0049]    By way of example only, preferred embodiments of the intention are now described with reference to the accompanying drawings, in which: 
           [0050]      FIG. 1  is a perspective view of one embodiment of the livestock handling system of the present intention; 
           [0051]      FIG. 2  is a top view of the embodiment of  FIG. 1 ; 
           [0052]      FIGS. 3 and 4  are perspective views of the pen of the system of  FIGS. 1 and 2  showing the entry gates in the closed and open positions, respectively; 
           [0053]      FIGS. 5A and 5B  are front and side views, respectively, of one embodiment of the door members of the entry and exit gates of the system of  FIG. 1 ; 
           [0054]      FIGS. 5C and 5D  are top views of the door members of  FIGS. 5A and 5B , respectively; 
           [0055]      FIGS. 6A and 6B  are front and rear views of the door members of  FIGS. 5A to 5D  in the closed position; and 
           [0056]      FIG. 7  is a top view of the pen of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0057]    A livestock handling device  10  in accordance with one embodiment of the present invention is shown generally in the accompanying figures. While the device  10  will be described in relation to its use in handling cattle, it will be appreciated that the device  10  could be equally employed for handling a variety of livestock, such as sheep, pigs and the like. 
         [0058]    As shown in  FIGS. 1 and 2 , the device  10  generally comprises a pen  12  for isolating and holding an individual animal and a sorting device  14  for sorting the animals exiting the pen  12 . The cattle may be sorted into at least two herds in accordance with a variety of sorting methods, which will be discussed in more detail later in the description. 
         [0059]    A chute  11  is provided to feed the cattle into the pen  12  in the direction of arrow A. The chute  11  is constructed such that the cattle can move in a single line towards the pen  12 , with minimal obstruction to hamper their progress. In this regard, the chute  11  could be constructed in a variety of forms, as would be appreciated by those skilled in the art. The cattle may be manually urged or prodded to travel along the chute  11  by a farmer or other individual, or the cattle may naturally progress along the chute  11  due to the orientation of the chute  11  with respect to its surroundings. 
         [0060]    The pen  12  is in the form of an enclosure having a pair of upright side walls  21 ,  22  arranged substantially parallel to the path of the cattle moving in the direction of arrow A. The walls  21 ,  22  are spaced apart a sufficient distance to accommodate the cattle passing therethrough such that an individual animal can be comfortably received therebetween. The walls  21 ,  22  are constructed in a manner that retains the animal within the pen  12  and that also enables a farmer to access the animal in a manner as will be discussed in more detail below. 
         [0061]    Entry gates  24  are provided at one end of the pen  12 , proximal the chute  11 . The entry gates  24  are actuated to move between an open position that permits entry of an animal into the pen  12 , and a closed position and prevents the animal within the pen  12  from backing out of the pen  12 , as well as other animals entering the pen  12 . Exit gates  26  are also provided at an end proximal the sorting device  14 , and are controlled to move between a closed position that encloses the animal within the pen  12 , and an open position that releases the animal from the pen  12  into the sorting device  14 . Upon entry of the animal into the sorting device  14 , the animal is sorted or drafted into an appropriated holding pen or race in accordance with a desired drafting/sorting regime employed by the farmer, which is not the subject of the present invention. 
         [0062]    As shown more clearly in  FIG. 2 , the walls  21 ,  22 , entry gates  24  and exit gates  26  define a space into which an animal is received so that it can be isolated from the rest of the herd for monitoring and/or assessment by a farmer. The length of the pen  12 , namely the length of the space between the entry gates  24  and the exit gates  26  (shown as X in  FIG. 1 ) is sufficient to accommodate the type of animal to be assessed/monitored. In this regard, the length X of the pen  12  may vary and is typically selected by the farmer in accordance with the type of livestock to be passed through the pen  12 . In the embodiment as shown, the length X is sufficient to accommodate cattle of variable lengths. 
         [0063]    As will be discussed below, as the cattle move through the device  10 , the operator controls the operation of the entry gates  24  to close behind the animal thereby capturing the animal in the pen  12  between the entry gates  24  and closed exit gates  26 . The entry gates  24  may be remotely actuated by the operator through a remote control pad or the like (not shown). In this regard, the opening and closing of the entry gates  24  can by synchronized to control the progress of the cattle through the device  10 . 
         [0064]    By isolating the animal in the pen  12  as it progresses through the chute  11  to the sorting device  14 , the animal can be monitored/assessed by the farmer/operator in a variety of ways. In the embodiment as shown, the pen  12  is configured to function as a weighbox for weighing the individual animals as they pass therethrough. In this arrangement, the weight of the animal can be ascertained and recorded to provide the operator with a record of the history of the animal, which can be used to ascertain the readiness of the animal for sale, and/or the health and condition of the animal. Upon assessing the weight of the animal, the sorting device  14  can be controlled to sort the cattle according to their weight. 
         [0065]    It will be appreciated that while the pen  12  is described in relation to a weighbox for measuring the weight of animals passing therethrough, the pen  12  could also be arranged to perform a variety of functions, for example, as a “cattle crush,” to capture the animal to assist a farmer in administering medication to the animal or branding the animal. 
         [0066]    The sorting device  14  is arranged adjacent the exit gates  26  of the pen  12  such that when the exit gates  26  open and the animal exits the pen  12 , the animal enters the sorting device  14 . The sorting device  14  comprises an elongated chute, similar to chute  11 , having a pair of pivoting side walls  27 ,  28 . The side walls  27 ,  28  are positioned to direct the exiting cattle in a desired direction under the action of one or more pneumatic actuators  29 . In the embodiment as shown in  FIGS. 1 and 2 , the side wall  27  is pivoted towards side wall  28 , thereby directing the exiting cattle in the direction of arrow B. It will be appreciated that by positioning the walls  27 ,  28  such that they are substantially parallel with the pen  12 , the exiting animals will be directed along path C, and by positioning side wall  27  such that it is substantially parallel with pen  12  and moving side wall  28  towards side wall  27 , the animals will be directed along path D. As discussed above, the path, which the exiting cattle take, is controlled in accordance with the measured weight of the animal. However, other factors can be used to determine the desired path of the exiting animal. 
         [0067]    A control system  5  is provided to control and coordinate the overall operation of the device  10 . The control system  5  generally comprises a central computer, such as a portable lap top computer, which controls the actuation of the entry and exit gates  24 ,  26  and the weighing arrangement of the pen  12 , as well as the pneumatic actuators  29  of the sorting device  14 . In this regard, the control system  5  can be employed so that the cattle passing through the device  10  can be sorted according to their measured weight. The control system  5  may comprise a memory storage that stores and records the weight data for each individual animal to provide to the operation information pertaining to the history of the animal, together with any other pertinent information. In this regard, an electronic reader may also be mounted to the pen  12  or chute  11  to identify the animal entering the pen  12  such that the weight of the animal can be stored against that particular animal. In this regard, the animal may be provided with an identification device, such as an ear tag or implanted microchip, which is detected by the electronic reader as the animal passes the reader to identify the individual animal. Such systems are well known in the art and will not be described in further detail. It will be appreciated that the control system  5  could also be in the form of an integrated computer system provided within the pen  12  or sorting device  14 . 
         [0068]    The control system  5  can be easily operated by a sole operator, thereby substantially reducing the requirement for additional labor to assist weighing and recording the information for each animal. 
         [0069]    Referring to  FIGS. 3 and 4 , the pen  12  of device  10  is shown in isolation. In  FIG. 3 , both the entry gates  24  and exit gates  26  are shown in the closed position as is the case when an animal is positioned within the pen for weighing. The pen  12  comprises a substantially rectangular frame  20  forming a substantially rectangular holding space for holding the animal, defined by the wall  21 ,  22  and gates  24  and  26 . The holding space is designed to accommodate the animal as securely as possible and to prevent the animal from turning around or significantly moving within the holding space. Such an arrangement reduces the likelihood of the animal causing harm or injury to itself by becoming cast or stuck within the pen  12 , and also reduces the likelihood of the animal causing damage to the pen  12  as a result of moving within the holding space. 
         [0070]    As is shown in  FIG. 3 , the upper portion  25  of the walls  21 ,  22  are substantially open and comprise an enclosed lower portion  23  made from a sheet of galvanized steel or the like. The open upper portion  25  is in the form of one or more steel bars. Such an arrangement provided in the upper portion  25  reduces the likelihood of any portion of the animal, such as the animal&#39;s legs, protruding or otherwise extending through the wall  21 ,  22 , as the enclosed lower portion  23  leaves no exposed gaps through which limbs can extend. This is particularly important if the animal becomes agitated and attempts to kick-out when in the pen  12 . The open upper portion  25  provides the operator with the ability to access the animal to administer medication or the like to the animal as required. 
         [0071]    As will be appreciated, cattle sizes can vary depending on a variety of factors, in particular the age of the individual animals. Hence, the holding space of the pen  12 , is generally designed so as it can readily accommodate the largest cattle sizes. In many instances, particularly where calves are being weighed and handled, the holding space of the pen  12  may be too large for the calves. Such an overly large holding space, can allow the animal to move around within the holding space of the pen, increasing the likelihood of the animal causing damage to the pen  12  or causing injury and harm to itself. 
         [0072]    As shown in  FIG. 4 , in order to deal with variable cattle sizes, the enclosed lower portion  23  of the side wall  22  is pivotally adjustable inwards. This inward pivotal movement of the side wall  22  reduces the width of the holding space of the pen  12  such that the animal is securely retained between the walls  21 ,  22  of the pen  12 , thereby being prevented from turning around within the pen  12 . 
         [0073]    To facilitate pivotal movement of the side wall  22 , the upper end of the enclosed lower portion  23  is pivotally connected to the frame  20  of the pen  12 . This allows the lower end to pivot inwards towards the wall  21 . An anchor pin  19  is provided adjacent to the lower end of the enclosed lower portion  23 , which is spring loaded to be received in one of a plurality of holes  17  provided in the floor  18  of the pen  12 . While only one side wall of the pen  12  is shown as being inwardly pivotal and adjustable, it will be appreciated that either or both side walls may be adjustable to facilitate a wide variety of animal sizes and shapes. 
         [0074]    While not shown in  FIGS. 3 and 4 , the pen  12  comprises a plurality of load cells mounted in the roof  15  of the pen  12 , to weigh the animal as it stands upon the floor  18  of the pen  12 . 
         [0075]    The animal is permitted into the pen  12  by moving the entry gates  24  from the closed position as shown in  FIG. 3  to the open position as is shown in  FIG. 4 . In the closed position, shown more clearly in  FIG. 6A , the entry gates  24  substantially block the path of the animal, presenting a substantially solid wall to the animal. When the entry gates  24  are in the open position, they provide a straight open path for the animal to pass, substantially free of obstacles, which may cause the animal to baulk or become unsure of what lies ahead of them. Such an arrangement is important, particularly with respect to providing steady flow of cattle through the device  10 , as any obstruction may require operator intervention to force the animal against their will through the device  10 . 
         [0076]    A similar arrangement is provided with the exit gates  26 . In this arrangement, when the animal progresses into the pen  12  and is presented on the floor  18  of the pen  12  for weighing by the load cells, the exit gates  26  are in the closed position as shown in  FIG. 6B . In this position, the exit gates  26  extend across the animal&#39;s path, thereby presenting a solid obstacle to the animal. Following weighing of the animal, the exit gates  26  are moved to their open position, thereby providing a straight open path for the animal to pass, substantially free of obstacles, which may cause the animal to baulk or become unsure of what lies ahead of them. 
         [0077]    The configuration of the gates  24 ,  26  and the manner in which they move between open and closed positions provides additional assistance in progressing the animal into and out of the pen  12 . In the embodiment as shown in  FIGS. 3 and 4 , the configuration of the entry gates  24  and the exit gates  26  is substantially the same. However, it will be appreciated that the entry gates  24  and the exit gates  26  could vary in construction and still fall within the spirit of the present invention. 
         [0078]    Referring to  FIGS. 5A and 5B , one embodiment of the entry gates  24  and exit gates  26  is shown. The gates  24 ,  26  comprise a pair of opposing door members  30 , which are activated to open and close the ends of the pen  12  so as to permit entry of the animal into the holding space of the pen  12 , and exit of the animal from the pen  12 . 
         [0079]    As shown more clearly in  FIGS. 3 and 4 , each door member  30  has a height that extends substantially the height of the pen  12 . In this regard, for handling cattle, the height of the door may be between 1.9-2.2 meters to facilitate a variety of cattle types and sizes. The door member  30  comprises a planar surface or panel  32 , which is substantially flat and extends the length of the door member  30 . The panel  32  may be formed from a sheet of galvanized steel such that the lower portion of the panel  32  is fully enclosed. An opening  33  (as shown by cross hatches in  FIG. 5A ) may be provided in the upper portion of the panel  32 , which opens into the holding space of the pen  12 . A guide member  31  is attached to the lower portion of the panel  32  and is angled to extend downward and away from the panel  32 . The guide member  31  is made from a sheet of galvanized steel, the purpose of which will be discussed in detail below. 
         [0080]    The panel  32  extends between an upper pivot plate  34  and a lower pivot plate  35 . As shown in  FIGS. 5C and 5D , the pivot plates  34 ,  35  are substantially triangular in shape and are made from a sheet of galvanized steel, thereby enabling the panel  32  to be welded or otherwise attached between the plates  34 ,  35 . In this regard, the panel  32  is attached to the plates  34 ,  35  along a base edge  36 , which forms the base of the triangular plates  34 ,  35  (see  FIGS. 5C and 5D ). In this arrangement, the width of the panel  32  is such that it extends from one end of the base edge  36  of the plates  34 ,  35 , but terminates before reaching the other end. This then results in a gap being formed between the end of the panel  32  and the end of the base edge  36  of the plates  34 ,  35 . 
         [0081]    A roller  38  is mounted in this gap to extend longitudinally between the pivot plates  34 ,  35 . The roller  38  is made from steel and is mounted such that it is free to rotate between the plates  34 ,  35  along its longitudinal axis. In this arrangement, the roller  38  is an extension of the panel  32  such that both the panel  32  and the roller  38  form a wall of the door member  30 . In this regard, when opposing door members  30  are in a closed position such that they are in abutting arrangement across the opening/exit of the pen  12  (as shown in  FIGS. 6A and 6B ), the rollers  38  of each of the door members  30  are located adjacent to each other. 
         [0082]    A pivot pin  37  extends from the outer surface of each of the pivot plates  34 ,  35  to facilitate mounting of the door member  30  to the frame  20  of the pen  12  as shown in  FIGS. 3 ,  4  and  7 . In this arrangement, the door members  30  are mounted at either sides of the opening to the pen  12 , and rotate with respect to the pen  12  to open and close the ends of the pen  12 . As shown in  FIGS. 5C and 5D , the pivot pin  37  is positioned opposite the base edge  36  of the plates  34 ,  35 , namely in the angle joining the other two sides on the plates  34 ,  35 . This arrangement allows the door member  30  to rotate about the pivot pin  37  under action of a pneumatic actuator, such that the door member can be moved between the opening and closing positions as will be discussed in more detail below. An actuator post  39  is also provided along an edge of the upper pivot plate  34  that extends between the roller  38  and the pivot pin  37 , to facilitate connection to a pneumatic actuator such that rotational movement can be imparted to the door member  30 . 
         [0083]      FIG. 6A  shows the door members  30  of the entry gates  24  in a closed position, as seen from the perspective of an animal awaiting entry into the pen  12 . As is shown, the door members  30  provide a barrier, which prevents an animal progressing further along the chute  11  into the pen  12 . The guide members  31  arranged at the lower portion of the panels  32  prevent the feet of the animal gripping the edge of the pen  12 , as they are angled to deflect the animal&#39;s feet away from the pen  12 . This arrangement prevents the animal awaiting entry in the pen  12  from stepping on the floor of the pen  12  which could have an adverse affect on the weight measurement being taken by the load cells of the pen  12 . Further, it ensures that the next animal entering the pen  12  is away from the entry gates  24  as they open, to assist the operator in controlling movement of the animals through the device. 
         [0084]    As is shown, when the door members  30  are in the closed position, the rollers  38  are arranged adjacent to each other with a small gap provided therebetween. This gap may be around 40-50 mm in width, thereby preventing the tail of the animal being caught between the closing door members  30 . Pinching of the animal&#39;s tail between the door members  30  as they close may cause irritation to the animal. 
         [0085]      FIG. 6B  shows the door members  30  of the entry and exit gates  24 ,  26  in the closed position as seen from within the pen  12 . In this arrangement, the panels  32  present a substantially flat surface to the animal, thereby enclosing the animal within the pen in a relatively safe and secure manner. 
         [0086]    As alluded to above and shown in  FIG. 7 , the opening and closing operation of the entry and exit gates  24 ,  26  is controlled by the control system  5 , which in turn is controlled by an operator. The control system  5  communicates with a pneumatic actuator  40  to move a reciprocating piston  42  in a desired direction. As shown, the pneumatic actuator  40  is centrally mounted in the roof  15  of the pen  12 , such that the piston  42  is positioned substantially between the door members  30  at each end of the pen  12 . The piston  42  is attached at an end thereof to the actuator posts  39  extending from the upper pivot plates  34  of the door members  30  by linking arms  44 . 
         [0087]    In order to open the pen  12 , the operator provides a signal whereby the control system causes the pneumatic actuator to move the piston  42  such that it is retracted within the actuator  40 , as shown with respect to entry gates  24  of  FIG. 7 . In this position, the door members  30  of the entry gates  24  rotate to an open position, thereby permitting entry of the animal into the pen  12 . In the open position, the panel  32  of the door members  30  is arranged parallel to the direction of the movement of the animal, thereby providing a substantially open and unrestricted path for the animal to travel into the pen  12 . The panels  32  of the door members  30  are rotated out of the way of the progressing animal such that they are located substantially adjacent the side walls  21 ,  22  of the pen  12 , so as not to substantially restrict the size of the opening of the pen  12 . 
         [0088]    Upon receiving the animal in the pen  12 , the control system sends a signal to the pneumatic actuator  40  to move the piston  42  into an extended position whereby the piston is moved in the direction of arrow G, out of the actuator  40 . Movement of the piston  42  in this manner causes the linking arms  44  to pull against the actuator posts  39  so as to impart rotational motion to the pivot plates  34 , thereby rotating the door members  30  into the closed position as shown in  FIGS. 6A and 6B . As the rollers  38  are arranged along the leading edge of the door members  30 , when the door members  30  are brought into the closed position, the rollers  38  ride across the rump of the animal as they close. Such an arrangement provides a positive force against the rear of the animal urging the animal into or out of the pen  12 . As the door members  30  roll across the rear of the animal, there is no significant pinching or squeezing of the animal that may cause discomfort resulting in the animal becoming agitated. Further, this action ensures that the door members  30  close around the animal, thereby substantially reducing the likelihood of more than one animal entering the pen  12  at any one time. 
         [0089]    Following admittance of the animal into the pen  12  and closing the entry gates  24 , the animal is then weighed by the load cells, whereby the control system  5  sets the sorting device  14  to direct the animal to a desired holding region. The exit gates  26  are then opened by the control system  5  causing the pneumatic actuator  40  to retract the piston  42  in the direction of arrow H. This in turn causes the door members  30  to rotate into their open position, whereby the panel  32  is parallel to the direction of movement of the animal, which provides a clear passage for the animal to exit the pen  12  and enter the sorting device  14  to be delivered to the desired holding region. 
         [0090]    Once the animal is clear of the pen  12 , the operator can then indicate to the control system  5  to open the entry gates  24  to allow the waiting animal to enter the pen  12  for weighing. 
         [0091]    While operation of the entry and exit gates  24 ,  26  has been described above as being pneumatically actuated, it will be appreciated that the gates  24 ,  26  could also be manually actuated by an operator and still fall within the spirit of the present invention. 
         [0092]    Further, it will be appreciated that while the above invention has been described as being controlled by a control system, such as an automated computerized control system, the present invention could be manually controlled as desired. 
         [0093]    It will be appreciated that the present invention provides a system for handling livestock that enhances the natural progression of the animal through the entire system. The rotary action of the entry and exit gates of the system provides a simple means for directing and guiding the animal into an enclosed space, without the need for excessive human intervention. Such rotational action of the entry and exit gates prevents tilting/jamming of the gates, which is common with existing sliding/swinging gate systems and also ensures that the doors operate within a confined space that does not extend beyond the pen and into the area occupied by the operators. Such a rotational action of the gates also provides for quick actuation of the gates to ensure that individual animals are captured and released from the pen as desired, thereby greatly improving the handling ability of the device. Further, the ability to alter the holding space of the system allows a system that can safely cater for a variety of sizes of stock, reducing the possibility of injury to livestock and equipment. 
         [0094]    It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made in the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.