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Title:
DEVICE AND METHOD FOR KILLING ANIMALS
Document Type and Number:
WIPO Patent Application WO/2013/151426
Kind Code:
A1
Abstract:
A device for killing animals comprises a container (10) for accommodating therein one or more animals (D) to be gassed. The container comprises a gas supply system (G) and is otherwise substantially closable in a gastight manner The device is characterized in that the container has a floor (20) for the animals and the gas supply system is arranged to introduce into the container gassing gas in a manner spread over the container via the floor. Further, a method is provided.

Inventors:
LAARMAN RUDOLPH EVERT (NL)
Application Number:
PCT/NL2013/050228
Publication Date:
October 10, 2013
Filing Date:
March 27, 2013
Export Citation:
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Assignee:
TOTAL CULLING CONCEPT GROUP (NL)
International Classes:
A22B3/00
Domestic Patent References:
WO2007120973A22007-10-25
WO2001091563A22001-12-06
WO2008128027A12008-10-23
WO2007107718A12007-09-27
Foreign References:
JP2007060925A2007-03-15
Attorney, Agent or Firm:
FEENSTRA, Louw et al. (XK Amsterdam, NL)
Download PDF:
Claims:
CLAIMS

1. Device for killing animals, comprising a container for accommodating therein one or more animals to be gassed,

wherein the container comprises a gas supply system and is otherwise substantially closable in a gastight manner, characterized in that the container has a floor and the gas supply system is arranged to introduce into the container a gassing gas in a manner spread over the container via the floor, and wherein preferably the floor is a floor for the animals.

2. Device according to claim 1, wherein the floor is provided with openings that yield an open fraction in a range between approx. 3% and 10% of open space with respect to the surface of the floor, preferably less than approx. 8%, and more preferably between 4% and 6% open fraction.

3. Device according to one of the preceding claims, wherein the floor is provided with a transporter having a conveyor belt that is preferably permeable to gas for the introduction through it of the gassing gas.

4. Device according to claim 3, wherein the conveyor belt is surrounded by the container and has an upper run and a lower run, wherein at least a part of the upper run constitutes a part of the floor and wherein at least a part of the lower run runs over or near a bottom wall of the container, and wherein then preferably at least a part of the lower branch is in contact with the bottom wall.

5. Device according to claim 3 or 4, wherein the container is provided with a support construction for supporting of at least a part of the floor part provided by the conveyor belt, and wherein preferably at least a part of the support construction constitutes compart- ments and the gas supply system has distribution openings in at least a number of compartments for the introduction of the gassing gas into those compartments.

6. Device according to one of the preceding claims, wherein the container has a bottom and at least a part of the bottom ends substantially without a barrier at an outside of the container and/or has a drain for liquids and/or manure.

7. Device according to one of the preceding claims, provided with an entrance and exit for the animals that are separate and closeable, wherein preferably the entrance and the exit are substantially facing each other, wherein preferably the entrance is provided with one of more folding doors and/or a bridge, and wherein the exit is provided with a sliding, lifting or rolling door .

8. Device according to one of the preceding claims, provided with a discharge transporter, preferably comprising a rolling track for the discharge of the gassed animals from the transporter of the container, and wherein preferably the discharge transporter links up to the floor, and wherein preferably at least a part of the discharge transporter is adjustable between at least two positions in which case that part with more preference is lockable in at least one of those two positions.

9. De.vice according to one of the preceding claims, wherein the floor has a relatively dark color, for example black, and wherein preferably the container has inside side walls that have at least a low, relatively dark colored part and above that a relatively light colored part, wherein with more preference the low part extends from near the floor to above eye height of the animals to be gassed.

10. Device according to one of the preceding claims, provided with a bright inside lighting, wherein preferably the container has an entrance and a rear wall substantially facing the entrance and at least the rear wall is at least illuminated relatively bright, relatively light colored, and/or comprises a window.

11. Device according to one of the preceding claims, provided with one or more releasable and/or movable fencings and/or dividers, in particular for dividing the floor into one or more animal compartments.

12. Device according to one of the preceding claims, wherein the device, in particular at least the container, is transportable, in particular on a truck, train and/or boat.

13. Device according to at least the preamble of one of the preceding claims, wherein the gas supply system is arranged for the supply of a gassing gas

substantially constituted of C02 and nitrogen gas and/or argon, wherein the CO2 fraction lies within a range between approx. 20% and 40%, preferably around 30%, and wherein preferably the gassing gas consists substantially of CO2 and nitrogen, for example approx. 30% C02 and approx. 70% nitrogen gas.

14. Method of gassing animals comprising

the introduction of one or more animals to be gassed into a container on a floor of the container,

the closing of the container in a substantially gas tight manner,

the introduction of a gassing gas into the container spread over the container through the floor and the thus gassing of the animals.

15. Method according to claim 14, using the device according to one of the preceding claims.

16. Method according to claim 14 or claim 15, comprising the removal of the gassed animals by means of a transporter with a gas permeable conveyor belt wherein at least a part of the conveyor belt provides at least a part of the floor for the animals.

17. Method of gassing animals, preferably according to one of the claims 14-16, comprising the gassing of animals with a gassing gas substantially comprised of CO2 and nitrogen gas and/or argon, wherein the fraction of CO2 lies within a range between approx. 20% and 40%, preferably around 30%, and wherein preferably the gassing gas consists substantially of CO2 and nitrogen, for example approx. 30% of C02 and approx. 70% of nitrogen gas .

Description:
Device and method for killing animals The present invention relates to a device according to the preamble of claim 1, as well as to a method, in particular for the killing of pigs, more in particular the killing of pigs as emergency slaughter.

Such a device and the use thereof are known from WO 2008/128027, wherein a forced gas flow is used with a controlled and time-dependent composition of the gas. A

disadvantage of this known method and device is that the method and the device are complex as a result of the required control of the process.

A method and device for the killing of animals are also known from WO 2007/107718. According to this document, a heavy suffocating gas is brought into the container steadily near the bottom thereof and the air is forced upwards by the even circulation of the gas.

A disadvantage of all these known methods and devices is that it appears impossible to determine the required time span for killing of the animals accurately and that the animals may have to fight a death struggle that prevents a quick and humane killing. Moreover, the animals many become agi- tated or in a panic. These disadvantages are undesired.

In order to diminish one or more of such disadvantages or to eliminate them, an improved method and device are provided in a first aspect, wherein the device is characterized in that the container has a floor and the gas supply system is arranged to bring the suffocation gas into the container in a manner spread over the container through the floor.

By bringing in the gas through the floor, it becomes possible to use a heavy suffocation gas and to spread it with relatively little turbulence through the container from be- low, in order to constitute a suffocating layer, preferably short of oxygen, at the bottom of the container for the gassing of the animals in order to anaesthetize and kill them.

For it has appeared that in the known devices and methods the circulation of the gas causes turbulences as a result of which it is possible that poorly mixed fractions are created with a low concentration of gassing gas and a high concentration of normal air from the environment. Animals in such poorly mixed fractions are not gassed efficiently and may be subjected to an undesired long and painful death struggle. This is especially true for the simultaneous treatment of groups of medium sized and/or large animals, such as may occur in the emergency culling of pigs, sheep, goats and/or cattle of stock breeding firms in relation to a contagious disease. Introduction of the gas above the bottom instead of through the bottom may increase the formation of such badly mixed fractions near the bottom, as a result of which lying animals that have been gassed partly may regain consciousness and a fast anesthesia and killing are postponed and a (further) extended death struggle may arise.

The present device prevents such undesired turbulence to a high degree, in particular when the floor is permeable to gas in the border areas as well as in a middle area, preferably substantially over its entire surface, for a distributed introduction of the gas. In such cases the introduction of the gas between animals of groups of simultaneously treated animals is facilitated, which reduces or prevents the amount of turbulence caused by the animals themselves and this simplifies the formation of an even gas blanket. As a result of this, the suffering of the animals is reduced or prevented. Preferably, the floor is provided with openings that yield an open fraction in a range of between approx. 3% and 10% of open space relative to the surface of the floor, preferably less than approx. 8%, and more preferably between 4% and 6% of open fraction. In this text "gassing" comprises stunning to immobility, making or letting become unconscious as well as killing, depending on what the situation implies in the context.

Further, a gassing gas is preferably different from nor- mal environmental air to such a high degree, that, when it is inhaled, at least after an amount of time, loss of consciousness and/or death occurs, preferably a gas with a low oxygen content, in particular substantially oxygen free gas.

A "heavy" gas comprises a gas having a weight and/or density higher than that of the normal environmental air in the container, for example CO2, argon, etc.

In order to simplify the formation of a gas blanket, a gas outlet system may be provided, preferably at or near an upper side of the container, with one or more gas outlets from an inside of the container for discharging displaced air. The provision of more outlets, in particular a number of discharge entrances arranged in a distributed manner over the container, is preferred since this makes it possible to prevent air pressure differences and turbulences to a higher degree. One or more outlets may be closable and pressure controlled, for example by an automatic and/or spring loaded valve or tap that opens at a certain overpressure inside the container, wherein the closing may prevent an undesired flow of air and/or intake of air from the outside. In order to prevent the leaking away of the gas blanket and/or turbulence, the container outside the gas supply system and the possible gas outlet system is substantially gas tight by at least avoiding as far as possible gas outlets and/or leaks below and near the intended upper side of the gas blanket.

Preferably the floor is a walking floor for the animals; this simplifies the transport of the animals into the container .

The floor may be fixed or at least partly movable. In an embodiment, the floor comprises one or more floor panels movably mounted in the container and preferably substantially entirely movable in and out of the container, for example a floor plate movable between or on rails and/or rolls. In a particular embodiment, the floor is provided with a transporter with a conveyor belt, preferably a conveyor belt to be driven by a motor. This simplifies at least the removal of the gassed animals and promotes a quick handling 0 of many animals, which is in particular important for emergency

clearing. With preference, the conveyor belt is gas permeable for the introduction of gassing gas through the conveyor belt; this simplifies the introduction of the gas in between the animals. A gas permeable conveyor belt may for example be constituted by an endless belt or chain having openings and/or chinks such as for hinged parts.

Preferably, a least a part of the conveyor belt consti- tutes substantially the entire floor. The conveyor belt may for example extend over substantially the entire available bottom surface of the container, in order to provide a large useful transport surface.

In an embodiment, the conveyor belt is surrounded by the container, thereby avoiding gas leaks. The conveyor belt may be and endless belt having an upper run and a lower run. Here at least a part of the upper run may constitute at least a part of the floor and also at least a part of the lower run may. run over or near a bottom wall of the container. Thus a space is defined between the upper and lower runs, where between the gas may be introduced, such that the gas may be supplied to the animals through the floor provided by the conveyor belt. The openings in the conveyor belt, in particu ¬ lar in the case of a conveyor belt having strips with small chinks between them, such as for example a chain of strips connected by links and/or hinges, provide a fine distribution of the gas flow that prevents undesired hefty turbulences and thus promotes the constitution of a tight gas layer. A conveyor belt of substantially gastight material, such as a dense plastic and/or rubber strip may be provided with perforations and/or other suitable gas permeable openings.

If the floor is constituted by an upper run, possible manure or other excrement of the animals may simply fall off the conveyor belt and be removed when the conveyor belt segments are turned around to the lower run, which promotes hygiene. Preferably, at least a part of the lower run runs close to a bottom wall of the container and/or is even in contact with the bottom wall. As a result of this, at least a part of the bottom wall of the container may be wiped clean by the conveyor belt. The conveyor belt and/or the bottom wall may be provided with one or more projections, such as hairs, strips or lips as a slide or wiper for the bottom wall respectively the conveyor belt.

In an embodiment with a conveyor belt, the container may be provided with a support construction for supporting at least a part of the floor part provided by the conveyor belt, with as a result that a stable walking floor is offered for the animals that therefore inspires confidence. This also al-lows for a relatively less strong conveyor belt. Preferably, at least a part of such a support construction creates compartments and the gas supply system has in at least a number of compartments dispensing openings for introducing the gas ¬ sing gas into those compartments. By offering the gas distributed in compartments below the floor, in particular below the conveyor belt, it becomes possible to create an even gas pressure below the floor and to prevent pressure and density differences and as a result thereof turbulence in the container. Preferably the compartments are mutually connected for a further equalization of the gas, wherein the open surface of the connection ( s ) between two adjacent compartments may be larger, or the gas flow resistance lower, than the open surface respectively the gas flow resistance of the floor above at least one of the respective compartments. This promotes an even gas (pressure) distribution in the neighboring compartments.

The container may have a bottom wherein at least a part of the bottom ends substantially without a barrier on an out- side of the container and/or has an outlet for liquids and/or manure, such that the bottom may be cleaned easily, for example by flushing it clean. The device may have a provision for slanting the bottom in order to simplify the flowing off of dirt by gravity, preferably in the direction of movement of the lower run of the transporter.

An embodiment may be provided with an entrance and exit for the animals that are separate and can be closed separately. Preferably, the entrance and exit are substantially facing each other. The entrance may be provided with folding doors and/or a bridge. The exit may be provided with a sliding-, lifting- or rolling door.

Provision of a separate and/or separately controllable entrance and exit prevents congestions and simplifies an efficient circulation of the incoming and outgoing animals. It also reduces possible unrest among the animals still to be treated, that could result from the observation of gassed congeners .

Arranging the entrance and exit opposite each other further spreads the (flows of) animals coming in and going out and turns out to stimulate the incoming animals more easily to enter the container when both are entirely or partly open. Further, the "airing" of the container is simplified more than with another arrangement, which may increase hygiene and operational safety for co-workers.

A bridge simplifies the introduction of the animals.

Such a bridge may bridge and/or mask the height occupied by the container and the possible transporter above a bottom floor. Sideward folding doors at the entrance side may help in creating a funnel that simplifies the introduction of the animals into the container. In combination with a bridge, certainly when it ends higher than the lower side of the doors thereby allowing the doors to overlap with the bridge, the folding doors may fence off and thereby prevent the incoming animals and/or co-workers to get off the bridge. It is also possible to use a movable bridge as a barrier for an entrance or an exit, thereby rendering separate doors

redundant .

A sliding, lifting, or rolling door, in particular a vertically moving door reduces the amount of floor surface required for mounting the device. Such a door may also usually be operated automatically in a simpler manner than folding doors. A vertically opening door simplifies a quick flowing out of heavy gassing gas ' , which increases safety for co-workers .

In an embodiment, the device is provided with a discharge transporter, preferably comprising a roller track, for the removal of the gassed animals from the transporter of the container. This simplifies the removal of the gassed animals. A roller track does not have to be driven when a lying gassed animal is placed thereon, which saves energy. Preferably the discharge transporter links up to the floor of the container, thereby enabling gassed animals to be removed from the container in a simple manner, especially in the case of a transporter in the container.

At least a part of the discharge transporter may be adjustable between two positions, in which case preferably that part is lockable in at least one of these two positions. This allows for adjustment of the discharge transporter to the operating circumstances. In particular the discharge

transporter may link up to the floor in one position and may enable the closing of the container exit in a second position .

Next to or instead of a bridge and/or a discharge transporter, it is also possible to provide another supply

provision, such as a transporter and/or a connection for an- other transporting system such as a truck, a fork-lift truck and such.

In an embodiment, the floor is relatively dark colored, for example black, and/or wherein preferably the container has inner side walls that have at least a low and relatively dark colored part and above that a relatively light colored part. In that case, the low part reaches preferably from near the floor to above eye height of the animals to be gassed, for example approx. 0.75-1 m of height from the surface of the floor in the case of pigs and small stock.

In an embodiment, the container is provided with a bright inner lighting wherein preferably the container has an entrance and a rear wall substantially facing the entrance and at least the rear wall is illuminated relatively

brightly, has a relatively light color and/or comprises a window .

Opposed to what is often thought, in particular pigs appear to dislike light walking floors, that they supposedly associate with water surfaces and thus with danger. A dark walking floor and dark walls with a lighter colour above appear to be perceived at least by pigs as agreeable or at least not distressing or frightening. Further, pigs appear to be averse from entirely dark places and curious to light places at the end of a relatively darker passageway such as provided by an (either or not artificially) illuminated rear wall. By one or more of these provisions, it becomes possible to let the animals remain relatively quiet and to herd them into the container easily. Dark parts of the side wall may also mask contamination.

Although groups of animals may remain calm in the provided device until and including the moment of definitive gassing, the device, in particular the container, is preferably provided with one or more releasable and/or movable fencing and/or dividers, in particular for the division of a walking floor into one or more animal compartments for being able to fix the position of one or more animals and/or for protecting animals and the device against each other.

The device, in particular at least the container, is preferably transportable, such as on a truck, train and/or boat. This makes cleaning of livestock possible at the location of an outbreak. The container may for example have a standard size of a freight- container, or even be a modified standard sea cargo container. The latter have the advantage that they are easily transportable, stackable and connect- able, that they are robust, made of material that can be machined well (for example steel that can be sawn and welded) and are closable with their doors substantially gastight by nature, in any case sufficiently gas tight for the intended use discussed here.

Hereby also a method is provided for the construction of

(a container for) a device as described here, wherein a container is provided with a gas supply system and/or a

transporter with a gas permeable transport belt for creating a floor.

In an embodiment, the device comprises a number of containers that are preferably similar of even almost identical, as a result of which it becomes easy to work in parallel.

In an aspect, a device is provided for the killing of animals, comprising a container for the accommodation therein of one or more animals to be gassed, wherein the container comprises a gas supply system and further is substantially closable in a gastight manner and/or according to one of the embodiments disclosed herein, characterized in that the gas supply system is arranged for the supply of a gassing gas substantially constituted of CO2 and nitrogen gas and/or argon in a ratio between approx. 20% of CO2 and approx. 80% of nitrogen gas and/or argon and 40% of C0 2 and approx. 60% of nitrogen gas and/or argon, preferably in a ratio of approx. 30% of CO 2 and approx. 70% of nitrogen gas and/or argon, wherein preferably the gas mixture substantially comprises no argon because it is expensive, such as between approx. 20% of CO2 and approx. 80% of nitrogen gas and 40% of CO2 and approx. 60% of nitrogen gas, preferably approx. 30% of CO2 and approx. 70% of nitrogen gas.

For the gassing of pigs until now usually almost pure

C0 2 is used. It appears that the pigs become very restless from this and suffer from pain. Almost pure argon is expensive and almost pure nitrogen may lead to restless behavior of the animals. Other gasses are expensive, ineffective, and/or poisonous for animals in such a manner that a reliable, quick, humane death and/or meat quality are influenced adversely. Additionally, the discharge of the used gas may cause problems, as opposed to natural atmospheric gases such as C0 2 , nitrogen and argon. The gas mixture referred to here turns out to constitute a reliable blanket of gas, certainly when the supply is from below, and it appears to provide a quick and certain anaesthesia and death for pigs, within a few tens of seconds respectively within a few minutes, wherein the animals do not become restless. Killing of ani- mals, in particular pigs, with such a gas mixture may thus, in any case in circumstances of emergency slaughter, be valued as humane.

In an aspect, a method of gassing animals is provided, using an embodiment of the device described herein. Thus, in a short time span many animals may be killed efficiently, such as is relevant for emergency cleanings.

In an embodiment the method comprises the introduction of one or more animals to be gassed into a container on a floor of the container, the substantially gas tight closing off of the container, the supply of a gassing gas in the container distributed through the floor of the container and the thus gassing of the animals and the removal of the gassed animals by means of a transporter with a gas permeable conveyor belt, wherein at least a part of the conveyor belt provides at least a part of the floor for animals. Preferably the animals are driven into the container while they are walking independently. This reduces actions and/or contact of personnel with possibly contaminated animals and it may prevent restless behaviour of the animals.

In a further aspect, a method for the gassing of animals is provided that comprises the gassing of animals with a gassing gas substantially consisting of C0 2 and nitrogen gas and/or argon in a ratio between approx . 20% of CO2 and approx. 80% of nitrogen gas and/or argon and 40% of CO2 and approx. 60% of nitrogen gas and/or argon, preferably in a ra ¬ tio of approx. 30% of CO2 and approx. 70% of nitrogen gas and/or argon. Because argon is expensive, the gas mixture preferably has no argon such as between approx. 20% of CO2 and approx. 80% of nitrogen gas and 40% of CO2 and approx. 60% of nitrogen gas preferably the gassing gas is approx. 30% of CO2 and approx. 70% of nitrogen gas.

The preceding will be clarified below, referring to the accompanying drawings, in which:

Fig. 1 is a top view of an embodiment of the provided device, wherein the view of Fig. 2 is indicated by lines II- II;

Fig. 2 shows a stage of the method in a side view of the container of Fig. 1, as indicated in Fig. 1 by line II-II, wherein in Fig. 2 the view of Fig. 1 is indicated by line I- I;

Figs. 3-4 show views as in Fig. 2 and different further stages of a method;

Figure 5 is a diagram of a progress of gas concentra- tions in the device.

It is noted that the shown embodiments only represent illustrative examples. The figures are further schematic and possibly not to scale,- wherein details that are unnecessary for an understanding may be left out. Further, substantially similar parts and aspects are indicated by substantially identical reference numerals.

Figs. 1-4 show a device 2 for the killing of animals, comprising a container 4 having an inner space S for accommodating therein one or more animals D to be gassed, for example pigs. The container is optionally on supports 6 by which the container can be oriented horizontally or rather inclined (not shown) . The container 4 comprises an entrance 8 and an exit 10, that are substantially closable by doors 12 and 14, respectively. Near the entrance 8 a supply provision 16 for animals is provided, here a bridge 16, and near the exit 10 a removal transporter ' 18 is provided. In this embodiment the bridge 16 is mounted hinged to the container 4 and it can be tipped up and optionally locked inside the container 4 for closing off the entrance 8 (Figs. 3-4) . This also simplifies the transport of the device 2. The container is provided with a floor 20 for the animals. A movable separation 22 is provided in order to demarcate a part of the floor 20. The separation 22 may be permeable to gas through openings, for example comprise one or more bars for counteracting turbulence. The container is provided with one or more light sources 24. The sidewalls have two colors, with a dark lower side and a light upper side. The inside of the rear door 14, that here is a vertical rolling door, has a light color. The bridge 16 has a dark color. Suitable dark colors are dark green, very dark grey and black. Suitable light colors are for example light grey and white.

The device 2 is provided with a transporter 26 compris- ing an endless conveyor belt 28 running over guides 30 such that an upper run 28A and a lower run 28B are constituted. One of the guides 30 is drivable via a controllable drive 32 for driving the conveyor belt 28. The upper run 28B constitutes a part of the floor at 20 and is supported by a support construction 34, thus providing a stable walking floor for the animals D. The lower run 28 runs near the bottom wall 36 of the container. The support construction 34 shown comprises rails 38 extending below the upper run 28B in the direction of movement of the conveyor belt 28. Between the rails 38 and the upper and lower runs 28A, 28B, compartments C are consti ¬ tuted, that are mutually in open connection for the

distribution of (pressure of) the gas, see also below.

The container is provided with a gas supply system 40 and a gas outlet system 41. In the shown embodiment, the gas supply system 40 is realized double and substantially symmetrical. Each part of the gas supply system 40 comprises a · terminal 42 for a gas pipe and/or gas reservoir G (Fig. 3), for example a gas tank, a gas tanker, and/or a gas generator on the basis of a suitable physical and/or chemical process for the formation of a gassing gas of one or a more gases, liquids and/or solids. The terminal 42 here is preferably accessible at an outside of the container 4. In the inner space S of the container 4 the gas supply system 40 is provided with a number of dispensing openings for example valves and/or holes spread out over the container and below the floor 20.

In the shown embodiment, the gas supply system 40 comprises a first duct 44, a divider 46 and number of second ducts 48. The second ducts 48 here are realized as rigid tubes provided with holes and which are mechanically connected to the rails 38 and form part of the support

construction 34. The second ducts 48 and the dispensing openings are arranged in a spread out manner over the container 4, such that a pattern is constituted of relatively equally spread holes below the floor 20, which is advantageous for a homogeneous distribution of the gas. In the shown embodiment, in all compartments C dispensing openings are arranged. The dispensing openings are preferably arranged for injection of the gas in a direction away from the floor, for example hori- zontally or downward. This causes a homogenization at the bottom side of the floor, leading to a more evenly distributed gas flow through the floor and impediment of turbulence above the floor.

One or more of the gas ducts 44-48 may comprise hoses and/or be fastened individually disconnectable . Further distribution ducts may be provided as well. One or more of the ducts may be ' provided with taps and/or valves that may be re ¬ motely controllable.

The container 4 may suitable have been made of a stan- dard 20 feet sea container, having inside dimensions of approx. 33.2 m 3 , (589 cm x 234 cm x 239 cm) . Here, a conveyor belt may be obtained with a running surface of approximately 200 cm x 560 cm, sufficient for the treatment of approximately 25 pigs ready for slaughter.

In order to obtain a useful inner space S of approximately 160 cm height for the animals, such that the container is also reasonably well to well accessible for human being, approximately 80 cm of height may be used for a transporter 26, lighting 24 and/or motor parts such as for example the control of the transporter and/or one or more doors, etc.

A fine distribution of openings for the flowing through of the gas through a floor, to be provided with an open fraction of within a range of between approximately 3% and 10% open space with respect to the surface of the floor, prefera- bly less than approx. 8%, and more preferably between 4% and 6% open fraction, such as by means of many hundreds to thou ¬ sands of small openings per m 2 of floor surface, results in a low flow resistance for the gas and turns out to allow for a very homogeneous gas distribution in the inner space S with little noticeable turbulence, also at a significantly more course distribution of dispensing openings of the gas supply system, for example in a range of approx. ten to approx. a hundred dispensing openings per m 2 . By providing a plurality of different successive distribution systems for the gas, such as here the staged distribution system of the gas supply system with spread out openings, a large number of small openings in the floor and further the division into compartments by the support construction, it becomes possible to obtain a homogeneous gas supply in the inner space at the lo- cation of the animals with a high flow rate.

A suitable conveyor belt is for example constituted by sheet formed hinging elements of for example approx. 15 cm x 5 cm at intervals of approx. 8 mm x 2 mm, as a result of which approx 3000 openings per m 2 are provided, resulting in an open fraction of approx. 4.8% (total open surface of openings / total floor surface) . Such a conveyor belt may

suitably be supported by a support construction having vertical ribs at a pitch of approx. 20 cm. suitable materials comprise metals and plastics, for example polypropylene, POM or nylon, which are durable and can be cleaned well ' .

A suitable gas supply system for a 20 feet sea container with this conveyor belt has for example as second ducts 42 eight tubes extending in a lateral direction of the container and being equally distributed in the direction of the length of the container. The tubes have in each compartment horizontal on either side an outflow opening, for example with a diameter of approx. 10-20 mm. In order to homogenize the gas pressure over the length of the tube, gas is supplied from both sides of the tube, although in one or more tubes gas may be supplied from a single side or from more positions along the respective tube.

An embodiment of use of the device 2 according to Figs. 1-4 comprises the main stages of loading animals, gassing animals and removing animals.

Figure 2 shows loading of the animals 6 into the device

2. The doors 12 of the container 4 are open and the bridge 16 has been installed and links up to the floor 20. The entrance 8 thus offers access for the animals 6 to the inner space S that is preferably brightly illuminated. Preferably, the rear door 14 is closed, so that the animals 6 do not observe what lies behind it. An optional fence 22 demarcates the end of the available part of the floor 20 for the animals and protects the rear door 14 and the end of the conveyor belt 28. The animals are driven into the container 4 over the bridge 16 on the floor 20, whereafter the container is closed in a substantially gas tight manner.

Figure 3 shows the container in a closed state. The entrance 8 is closed gas tight by the doors 12 which are protected by the tipped up bridge 16. From a gas reservoir G connected to a gas supply system 40, a heavy gassing gas is introduced into the inner space S of the container through the floor 20, wherein the gas is divided by the equally spread dispensing openings and the openings in the conveyor belt 28 (arrows) and no noticeable turbulence occurs.

For pigs the gas contains for example approx. 30% of C0 2 and 70% of nitrogen, substantially without further gases. In particular the supplied gas contains substantially no oxygen gas, e.g. much less than 3% of (¾, preferably less than 1% with more preference no more than 0.1%.

By the equal distribution and certainly by use of the gas that is relatively heavy in comparison to air an oxygen free gas layer (indicated by boundary line H in Fig. 3) is built up from below and the air originally present is displaced upwards, wherein this may leave the inner space S through the gas outlet system. All animals are equally and effectively gassed by the homogeneous gas layer.

Fig. 5 is a graph of the measuring results of a test showing that, when a container is used on the basis of a 20 feet sea container with a conveyor belt and gas supply system as described above into detail with a gas supply rate of 15 mVminute thus in approx. a minute at approx. 70 cm above the floor (average head height of pigs), the oxygen content of normally approx. 21% is halved and within approx. 2 minutes has been reduced to approx. 5% and after 3 minutes may be maintained at less than 0.3% for many minutes. As a result of this, the animals 6 are stunned and will die in a long- lasting stay. It has appeared that matured pigs (approx.. 120 kg) fall over under these circumstances on average after 130 seconds, after 180 seconds show no more brain activity (iso- electrical EEG) and after 350 second do not move anymore at all. A longer stay in the gas mixture, for example 10 minutes, guarantees death of animals also well over 250 kg, such that in the case of an emergency cleaning of a pig farm also heavy sows and boars can be killed in a reliable and humane manner with a cycle duration that is sound from a business economical perspective.

Fig. 4 shows the removal of the suffocated animals 6. The gas supply is closed and may be disconnected or remain connected. The rear door 14 is opened, allowing the gas to escape. Possibly the front doors 12 may also be opened and/or mechanical ventilation may be applied. By leaving the bridge 16 tipped up in that case, the suffocated animals 6 remain invisible from the front side, if the bridge is optically sufficiently closed because it is massive or has overlapping bars. After removal of the separation 22 that in this example may be slid or lifted upward by a motor, the suffocated animals 6 may be removed from the container 4 by means of the transporter 26 (see the arrows) .

In the shown embodiment, the discharge transporter 18 comprises a roller track. For the freedom of movement of the rear door 14 a part 18A of the discharge transporter 18 is movable. Here the part 18A of the discharge transporter is mounted on a hinged support 50 that provides adjustability to the part 18A to a first position wherein the rear door 14 may close the container (Figs. 2-3) and a second position wherein the discharge transporter links up to the conveyor belt 28, thus allowing the suffocated animals 6 to be brought onto the discharge transporter in a simple manner for further transport and/or treatment. The invention is not limited to what is described above, but may be realized in different manners varied within the scope of the claims. For instance, in an embodiment the gas supply system may be arranged for the generation of the suf- focation gas in the container by transport and distribution of one or more gas forming substances, such as one of more vaporizing, atomizing or sublimating substances including supercritical substances. An example thereof is supercritical C0 2 at a high pressure that becomes a gas near an outlet opening of the gas supply system.

One or more floors, a supply provision, and/or a removal provision may be provided with one or more transporters, in series and/or parallel that may possibly be of different types. Transporter of other kinds may also be provided. The device may be provided with a remote control for one of more components. A liquid connection for cleaning and/or dust reducing or contamination reducing mist may be provided. A controller may be provided for the automated execution and/or of (a part of) a cycle. One or more sensors for detection of gas concentrations and/or failures etc. Alarm means such as lamps, rotating light, horns, etc. may be provided, possibly separate from or in combination with a sensor.