Abstract:
An erectable module for gassing animals, the module including a frame and at least one cover being supported by the frame to define a chamber.

Description:
TECHNICAL FIELD 
       [0001]    The present invention generally relates to harvesting animals for slaughter and use in the food industry and, more particularly, to a device for euthanizing animals on an industrial scale. The present invention has particular application to poultry. 
       BACKGROUND 
       [0002]    The harvesting of animals for slaughter can be an inhumane and gruesome process that can be traumatic for the animals and the people harvesting those animals. The inhumane nature of the harvesting process can be exemplified by the following description of current practice in the chicken farming industry. 
         [0003]    Free range chicken farms typically comprise at least one large barn (which is approximately 100 m long and 12 m wide) which may contain around 15,000 chickens. Before slaughtering the chickens, the chickens are given no food or water for 12 hours to reduce the amount of excrement and urine within their bodies. The chickens are then gathered in the barn and corralled down temporary, purpose built tunnels within the barn. Workers then grab the chickens by the legs as they emerge at the end of the tunnels and shove the chickens into cages. The cages are typically 2.8 metres wide, 1.05 metres depth and 1.55 metres high. Around 30 or more birds are put into each cage. The conditions are cramped. 
         [0004]    Putting the chickens in cages can be a brutal process, as the farmer&#39;s workers generally have little regard for animals which are shortly destined for slaughter. The workers must psychologically desensitise themselves to cruelty, or be individuals who have such inclinations naturally. The chickens are often injured and stressed whilst being captured and may sustain broken limbs and bruising. This can be a difficult process for the farmer to watch or partake, because he or she has raised those chickens from hatchlings with a relative degree of kindness and has treated those chickens as pets to some extent. 
         [0005]    A great deal of noise is created by the chickens within the barn during the harvesting process. This noise often carries to neighbouring barns containing other chickens and creates a great deal of distress amongst those chickens. Thereafter, those other chickens often flee at the sight of the farmer and his workers, as they now are aware of what humans are capable of. The intelligence of these birds is often underestimated. 
         [0006]    The caging process typically takes 6 to 9 hours. The chickens are left in cages outside the barn, in the sun, before being loaded by forklift onto semi-trailer trucks and driven to a slaughterhouse. Most truck drivers prefer to drive in groups and will not leave the farm with the chickens until all of the cages have been loaded onto all of the trucks at the end of the day. Slaughterhouses are often located many hours travel from chicken farms. Most chickens will not survive the caging process and journey to the slaughterhouse due to shock, injury, dehydration and/or fatigue. 
         [0007]    At the slaughterhouse, the chickens are removed by hand from the cages and placed upside down on hooks, which clasp their feet and often penetrate the skin of the chicken. This can be an incredibly painful and distressing process for those chickens which are still alive. The chickens are then typically passed into a water bath with an electric current running through it to electrocute them. 
         [0008]    When battery chickens (which are kept in cages) are to be slaughtered, the common practice is to remove each chicken from its cage by hand and then break their necks. The chickens are then thrown into a portable storage container along with other chickens. However, this frequently does not kill the chicken, but merely paralyses it. In this situation, the chicken is still able to experience pain and suffering after its neck has been broken and it has been thrown into the storage container. 
         [0009]    If a serious disease outbreak occurs within a population of chickens, there are a number of other methods of exterminating the chickens. One method involves gathering the chickens in a barn, opening canisters filled with carbon dioxide gas and draping large sheets of plastic over the chickens and gas canisters to suffocate the chickens. The gas escapes directly into the environment because the sheet of plastic only contains the gas momentarily and the barn itself is unsealed. This gas can be fatal to humans. Workers must wear gas mask respirators. A large amount of gas is wasted using this method. This drastic method of exterminating chickens is only employed in emergency situations and is not cost effective for general industrial use. The dead chickens are then buried between layers of sawdust. Another method of exterminating diseased chickens is to set the diseased birds on fire whilst they are still alive (this method of extermination is known to have been practiced in Indonesia). 
         [0010]    Hence, a more humane and efficient method of harvesting animals for slaughter is desired. The preferred embodiment of the present invention is directed to an improved device for slaughtering animals, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice. 
         [0011]    The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge. 
       SUMMARY OF INVENTION 
       [0012]    According to a first aspect of the present invention, there is provided an erectable module for gassing animals, the module including a frame and at least one cover being supported by the frame to define a chamber. 
         [0013]    Preferably, the frame is formed from an interconnected three-dimensional lattice of inflatable tubes. Advantageously, the frame may be inflated on site to gas the animals. The frames are adapted to be connected in series so as to form a module network. 
         [0014]    The tubes may have one or more internal bladders surrounded by an external sleeve, so that the tubes can withstand a higher degree of pressure. 
         [0015]    In some forms of the invention, the frame is frame is unitary. However, in other forms of the invention, the frame may comprise discrete sections adapted to be connected to form a module. Discrete sections may be used when a module is required to surround an existing structure such as battery cages. 
         [0016]    Preferably, the animals are euthanized when gassed. However, the modules may also be used to anesthetize animals. The preferred gas is carbon dioxide. The level of this gas inside the chamber can be used to either euthanize or anesthetize the animals. 
         [0017]    The gas could be trapped in a liquid, such as foam. Conventional fire-fighting foam can be used to euthanize the chickens. Alternatively, the gas can be trapped in a solid form, such as absorbent granules which are adapted to release a poisonous gas. 
         [0018]    The erectable module may comprise a removable roof portion. The cover may include a single sheet or multiple sheets of material for affixing onto the frame. The material may be formed from polymeric material. 
         [0019]    The device may include a gas conduit for introducing gas into the chamber. The device may include a pump for pumping gas in or out of the conduits. 
         [0020]    The frame may include a plurality of handles to facilitate handling. Anchor means may be used on the frame so that ground pegs or weights may be fastened to the device. 
         [0021]    According to a second aspect of the present invention, there is provided a device for gassing animals, the device including:
       (a) a frame having at least one inflatable portion;   (b) at least one cover being supported by the frame to define a chamber; and   (c) means for supplying gas into the chamber in which the animals are located.       
 
         [0025]    According to a third aspect of the present invention, there is provided a method of euthanizing chickens on a free-range farm having a barn, the method comprising:
       (a) installing one or more modules defining a gas chamber outside the barn;   (b) ejecting chickens from a barn during the day,   (c) closing the doors to the barn so as to prevent the chickens from re-entering the barn;   (d) opening the modules before nightfall;   (e) allowing the chickens to roost underneath the modules;   (f) sealing the modules; and   (g) gassing the chickens.       
 
         [0033]    According to a fourth aspect of the present invention, there is provided a method of euthanizing chickens on a free-range farm having a barn, the method comprising:
       (a) installing one or more modules defining a gas chamber inside the barn;   (b) closing the doors to the barn so as to prevent the chickens from exiting the barn;   (c) waiting until nightfall;   (d) entering the barn;   (e) placing the chickens inside the modules;   (f) sealing the modules; and   (g) gassing the chickens.       
 
         [0041]    According to a fifth aspect of the present invention, there is provided a method of euthanizing chickens on a free-range farm having a barn, the method comprising:
       (a) installing one or more modules defining a gas chamber adjacent to a door of the barn;   (b) driving the chickens through the door and into the modules;   (c) closing the door to the barn;   (d) sealing the modules; and   (e) gassing the chickens.       
 
         [0047]    According to a sixth aspect of the present invention, there is provided an erectable module for gassing animals inside an animal shelter, the module comprising one or more retractable covers to define a chamber within the animal shelter. 
         [0048]    The animal shelter may be a barn for poultry. Preferably, the retractable covers are awnings made of PVC. The awnings should be gas impervious. A first awning can be mounted on the roof of the barn and drawn downwards to the floor of the barn. A second awning can be mounted beneath a mesh floor of the barn and retracted or extended from outside the barn. The first and second awnings form a chamber inside the barn for gassing the poultry. The awnings can be extended or retracted using a manually or automatically operated crank. 
         [0049]    Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0050]    Various embodiments of the invention will be described with reference to the following drawings, in which: 
           [0051]      FIG. 1  is an illustration of a series of rectangular and triangular shaped modules according to the present invention, in use by a farmer next to a chicken barn. 
           [0052]      FIG. 2  is a perspective view of the rectangular module of  FIG. 1 . 
           [0053]      FIG. 3  is a perspective view of the rectangular module of  FIG. 2  at a first stage of assembly. 
           [0054]      FIG. 4  is a side perspective view of the rectangular module of  FIG. 2  at a second stage of assembly. 
           [0055]      FIG. 5  is a perspective view of a fanner accessing a gas canister in a rectangular module using a built in glove. 
           [0056]      FIG. 6  is a perspective view of the triangular shaped module of  FIG. 1 . 
           [0057]      FIG. 7  is a perspective view of a module network according to another embodiment of the present invention, in use on a battery of chicken cages. 
           [0058]      FIG. 8  is a perspective view of a dome-shaped module according to another embodiment of the present invention. 
           [0059]      FIG. 9  is a side view of an assembly of operating the rectangular module of  FIG. 1  inside a barn. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0060]    Chickens  10  on free range farms are typically housed in a large barn, such as barn  12  shown in  FIG. 1 . These types of barns typically hold around 15,000 chickens. The chickens  10  enter and exit the barn  12  via doors  14 . The chickens  10  are kept within the barn  12  overnight and the doors  14  are closed to protect the chickens from predators, such as foxes or dogs. The chickens  10  on the highest pecking order will ordinarily come out of the barn  12  when the doors  14  are opened in the morning. Chickens  10  which are lower on the pecking order may never come out of the barn  14 . 
         [0061]    Rectangular modules  16  and triangular modules  18  according to the present invention are placed alongside the walls  20  of the barn. Triangular modules  18  (see also  FIG. 6 ) can be placed in front of the doors  22  of the barn  12 . The modules  16  and  18  can be connected in series by rolling up the side panels  24  of the modules  16  and the side panels  90  of the triangular modules  18  (see  FIG. 6 ). The side panels  24  can be held up by means of a clip and strap mechanism  26 . 
         [0062]    The chickens  10  can be driven into the triangular modules  18  from inside the barn  12 , or they can voluntarily huddle under the rectangular modules  16  and triangular modules  18 . 
         [0063]    Any chicken  10  which leaves the barn  12  will return to the barn  12  to roost before nightfall for a sense of security. If the doors  22  to the barn  12  are shut before the chickens  10  return to the barn  12  to roost, the natural tendency of the chickens  10  is to huddle against the walls  20  the barn for security. If the doors  22  to the barn  12  are shut before the chickens  10  can re-enter the barn  12 , the chickens  10  will seek any shelter they can find near the walls  20  of the barn  12 . The modules  16  and  18  provide that apparent shelter. The chickens naturally go to sleep huddled together on mass. Unless the chickens are greatly disturbed in the dark, they will not move as they have very poor night vision. 
         [0064]    Once a sufficient amount of chickens  10  have entered the modules  16  and  18 , the side panels  20  may be rolled down and zipped shut. The zips, such as zip  30  in  FIG. 1 , may have covers over them to prevent the ingress of dirt within the zip and to prevent the escape of the gas from the modules. 
         [0065]    The farmer  28  may connect gas canisters  32  via conduits  34  to input valves  36  on the modules  16  (see  FIG. 2 ). The pressure from the canister  32  distributes the gas within the modules  16 . Carbon dioxide is used to asphyxiate the chickens  10 . 
         [0066]    A standard hose connection for a gas canister may freeze due to the pressure and speed at which the gas emerges from the canister. One means of overcoming this problem is to have a wider hose so that the gas is not forced at high speed through the valve of the canister. A larger orifice from the canister leading into hose of a 5 cm diameter is effective in transferring gas over distance without freezing (see  FIG. 2 ). 
         [0067]    A certain level of carbon dioxide will anesthetize the chickens  10  (i.e. render the chickens unconscious), but a higher level of carbon dioxide will euthanize the chickens  10 . In some situations, the chickens may need to be anesthetized, rather than euthanized. Chickens may need to be anesthetized before their beaks are clipped. A machine is used to clip the chicken&#39;s beaks. The clipping process can be distressing for the chickens. If the chicken&#39;s heads are not correctly aligned within the clipping machine, an inexperienced operator of the clipping machine may prematurely remove the chicken from the machine and break the jaw of the chicken during the process. The jaws of chickens are often broken during the clipping process. 
         [0068]    As shown in  FIG. 2 , each module  16  may comprise a gas meter  38 , so that the farmer  28  may ascertain the gas level inside the module  18 . The modules  18  may comprise a gas extraction outlet  40  so that a hose  42  connected to a pump  44  may be used to expel the carbon dioxide gas at a safe distance from the module  16  (for occupational health and safety reasons). The pump  44  can be used to assist with the transfer of gas from one module to the next by connecting the outlet of one module to the inlet of another. 
         [0069]    The rectangular modules  16  can also be placed inside the barn  12 . The internal floor of the barn  12  (not shown) is typically comprised of grates which are suspended above the ground. Chicken faeces drop through the grates onto the ground, which is approximately 1 meter beneath the grates. Accordingly, a plastic sheath (not shown) is required to be placed underneath the modules  18 , so that the gas cannot escape from beneath the modules  16  and asphyxiate the user, such as farmer  28 . 
         [0070]    In another form of the invention, fire extinguishing foam may be introduced into the modules  16  to suppress the oxygen levels and thereby asphyxiate the chickens  10 . In this embodiment of the invention, the foam may be introduced into an orifice (not shown) located at the centre of roof panels  47  and  49  (see  FIG. 1 ) of the module  16 . A flange located underneath the orifice inside the module  16  may be used to ricochet and disperse an incoming stream of foam around the inside of the module  16 . 
         [0071]    In other forms of the invention, the gas could be produced by granules impregnated with a poisonous agent, such as hydrogen cyanide (prussic acid). These granules could be introduced into the modules to poison the animals. 
         [0072]    Chicken barns are often constructed so that the ground slopes away from the walls of the barn. Accordingly, an awning  45  may be used to fasten the module to the wall  20  of the barn  12  to prevent the module  16  from sliding down the slope. The awning  45  may have side drapes (not shown) to prevent chickens  10  from accessing the area under the awning  34  between the module  16  and the wall  20  of the barn  12 . It could be difficult for the fanner  28  to remove chickens  10  from behind the awning  45 , particularly if multiple modules are joined in a series. 
         [0073]      FIG. 3  shows the internal components of the module  16 . The module  16  has a frame  48  with horizontal supports  50  and vertical struts  52 . The modules  16  are made of plastic and the frame  48  is inflatable to reduce the overall weight of the modules  16 . This confers a number of advantages on the invention, including enabling a single user to readily lift and move the light frame  48  and retrieve the dead chickens underneath it. In addition, the inflatable frame  48  can be deflated and readily stored or transported when not the module  16  is not in use. Plastic is also a cheap and readily available material for mass production of the modules. 
         [0074]    In another embodiment, the frame  48  could include an internal inflatable bladder covered by an external sleeve (e.g. of one or more layers of polyvinyl chloride), which would enable the construction of stronger (and lighter) but slimmer frames. The bladder allows an increased amount of pressure to be introduced into the frame  48 . The strength of the frame  48  depends on the amount of pressure in it. A normal frame  48  with no bladder would burst under the pressure which can be introduced into the bladder/sleeve system. 
         [0075]    In an alternative embodiment of the present invention, the frame  48  could be filled with extruded polystyrene foam (e.g. Styrofoam™). 
         [0076]    The seams of the module  16  are heat-welded, so that the seams will not leak (unless punctured). A blower would be required to keep the module continuously inflated if the seams are stitched rather than welded, as stitches are not air-tight. 
         [0077]    The frame  48  is inflated at a single inflation valve  54  (see  FIG. 3 ). The frame  48  can incorporate a relief valve  56  to prevent the accidental over-inflation of frame  48  by a user. 
         [0078]    The frame  48  has a recess channel  58  for supporting a first roof lattice  60 . The embodiment of the invention shown in  FIG. 3  also has a second roof lattice  62 . Each roof lattice  60  and  62  may be separated from the frame  48 , so that the farmer  26  may readily retrieve or place chickens within the module  16 . 
         [0079]    In some embodiments of the invention, the frame  48  can have a mesh  64  to allow ventilation for chickens when the roof lattice  62  has been removed. The mesh  64  also prevents the escape of the chickens from within the module  16  when the roof lattice  62  is opened. 
         [0080]    The lattices  60  and  62  have covers (see  FIG. 2 ) made of an air impervious material polymeric plastic material such as PVC. The covers can be opaque or transparent. Chickens are likely to feel a greater sense of security within the module  18  if the panels are opaque. However, it may be useful for at least a portion of the covers to be transparent so that the farmer can see how many chickens are inside the module  16 . 
         [0081]    One or more anchor lugs  66  may be positioned around the frame  48  to connect to a rope to a peg for insertion into the ground (as shown in  FIG. 2 ), or weights to hold the frame  48  down. The frame  48  and roof lattices  60  and  62  may have one or more handles  68  attached to it to facilitate handling. 
         [0082]      FIG. 4  shows a first gas conduit  70 , having an inlet  72  and an outlet  74 , which is connected to the roof lattice  60 . The conduit  70  may be perforated so that it may distribute the gas evenly around the interior of the module  16 . The second roof lattice  62  also has a gas conduit  76  which has an inlet  78  and an outlet  80 . The outlet  74  can be connected to an inlet  78 . A pump (not shown) can be used to draw the gas from the first gas conduit  70  through to the second gas conduit  76 . 
         [0083]      FIG. 5  shows another means of introducing gas into the module  16 . In this embodiment of the invention, a front panel  82  of the module  16  has an in-built glove  84 , so that the farmer  28  can reach inside the module  16  and open the gas canister  86 . This method of operating the invention quickly releases the gas into the module  16 . The quicker the gas is released into the module  16 , the quicker the chickens  10  are euthanized and the less suffering they experience. The gas canister  86  can be placed next to a metal baffle plate  88  so that the jet stream of gas emerging from the canister  86  does not hurt a chicken before euthanizing it. 
         [0084]    A base panel (not shown) for the module  16  is required when the module  16  is to be used inside a chicken barn. This is because the floor of a typical chicken barn is comprised of plastic slats that are perforated with holes for manure to pass through to the ground, which is typically around 1 metre beneath the slats. The gas could escape through the slats and pose a safety hazard if the module  16  does not have a base panel in these circumstances. 
         [0085]      FIG. 6  shows the triangular shaped module  18  in more detail. In particular, the module  18  has side panels  90  which can be rolled up, so that it can connect with a rectangular shaped module  16  (as shown in  FIG. 1 ). The module  18  is shaped as a triangle because the large side  92  is adapted to cover the door  22  of the chicken barn  20 . The module  18  has a top-panel  94 , which can be rolled up so that the farmer can access the chickens  10  within the module  18 . 
         [0086]      FIG. 7  shows another embodiment of the invention for chickens  96  in battery cages  98 . These chickens  96  are kept in the cages  98  for their entire life. They lay eggs  100  in their cages  98 , which are then automatically rolled onto conveyor belts  102 . When the hens  96  reach a certain point in their lifetimes, they no longer produce an efficient amount of eggs per day. Consequently, they have to be exterminated and replaced with new chickens. The process of extermination is brutal and involves removing each chicken  96  from its cage  98  by hand and breaking its neck. This often paralyses the chicken rather than kills it. The paralysed chickens are then thrown into a storage container which moves down the aisle  104  between the cages  98 . The paralysed chickens can still experience pain and distress before they die. The dead chickens are then sold off to the meat market. Obviously, it would be more humane if the chickens  96  experienced little or no pain before a quick death. 
         [0087]    One solution to this problem is provided in the form of module  106 . The module  106  encompasses the cages  98  to euthanize the chickens  96 . As shown in  FIG. 7 , the farmer  28  places vertical panels  108  against the front of the cages  98  using the handles  110 . One or more horizontal panels  112  are placed on top of the cages  98  to create a seal with the vertical panels  108  and form the module  106 . Carbon dioxide gas can be transferred into the module  106  from a canister  114  via a hose  116 . This suffocates the chickens  96  so that they can be easily removed from their cages  98 . 
         [0088]    Modules of any shape or size can be made according to the present invention. For example,  FIG. 8  shows another embodiment of the invention in the form of a dome shaped module  118 , including a lattice framework which can cover a large area and many chickens. 
         [0089]      FIG. 9  shows a side section view of the barn  12  of  FIG. 1 . The barn  12  has a hutch  120  in which the chickens  10  lay their eggs. The hutch  120  runs the length of the barn  12  and divides it into two halves. The barn  12  has a floor  122  which sits above a trench  124 . The trench  124  is dug beneath ground level  126  outside the barn  12 . The floor  122  is made of a series of slats which have a mesh that allows the manure  127  of the chickens  10  to pass through to the trench  124 . 
         [0090]    One or more modules  16  are placed in the barn  12  along with one or more gas canisters  32 . If gas is pumped into a module  16  which does not have a base, it would escape through the mesh in the floor  122  and potentially suffocate the farmer  28 . 
         [0091]    In order to overcome this problem, the barn  12  has an assembly according to present invention to contain the gas. A first part of the assembly is an awning  128  which is drawn from roof of the barn  12  to the floor  122  of the barn  12 . The awning  128  should be drawn partially along the floor  122  and secured using a hook  130  to create a seal. The awning  128  divides the right hand side of the barn  12  from the left hand side. Another part of the assembly is an awning  132 , which can be extended and retracted under the floor  122  of the barn  12  using a crank  134 . The awnings  128  and  132  form a chamber on the right hand side of the barn  12 . 
         [0092]    The chickens  10  on the right hand side of the barn  12  can be herded into the modules  16 . The gas canisters  32  can then be opened to gas the chickens  10  in the right hand side of the barn  12 . The gas can then slowly dissipate outside the barn  12  so that the chickens  10  on the left hand side of the barn remained unharmed. 
         [0093]    In other embodiments of the invention, the modules  16  may not be required and the awnings  128  and  132  can form an erectable module in which to euthanize the chickens. However, in this embodiment of the invention, more gas is required to fill the volume of space defined by the awnings  128  and  132 . 
         [0094]    Various embodiments of the frame of the module are within the scope and ambit of the present invention. In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.