AU751926B2 - Method of stimulating animals during slaughter - Google Patents

Description

WO 00/27211 PCT/AU99/00983 1 METHOD OF STIMULATING ANIMALS DURING SLAUGHTER This invention relates to animal slaughter treatment procedure, and in particular to a method of stimulating animals during slaughter for the purpose of eliminating or controlling reflex activity.

A major problem which has always existed during animal slaughter procedure has been the risk of serious injury to the slaughtermen as a result of reflex kicking of the animal being slaughtered. Prior to slaughtering, it is normal procedure for the animal to be stunned, eg by means of a mushroom-head stunner or a type of bolt gun, following which the stunned animal is placed on a conveyor (or hung therefrom) and the jugular vein opened at the neck to bleed the animal. The animal may then be laid on a work surface with its legs extending upwardly or it may be kept hanging during the subsequent meat cutting procedure. Throughout this procedure, several workmen are involved, eg the sticker and rodder, head dropper, dehorner and leggers, and there is always the danger of any one of them being kicked or buffetted by the dead animal.

A further problem with existing procedures is that insufficient initial bleeding of the animal occurs and the blood continues to drain from the animal as it moves to successive work stations located around the kill floor area. This normally results in significant quantities of blood being sprayed into the air and onto the workmen.

It is desirable therefore that a procedure be devised which will effectively reduce or eliminate the dangerous reflex activity of the animal after the initial stunning step. It is also desirable that a greater amount of blood is drained from the animal while it is on the bleed rail, thereby reducing the amount of bleeding which occurs when the dead animal proceeds past the sticking area.

SUBSTITUTE SHEET (RULE 26) RO/AU It is the main object of the present invention therefore to provide an improved method of slaughtering animals which will eliminate or at least significantly reduce the risk of worker injury as a result of reflex activity of the animal being slaughtered.

It is another object of the present invention to provide an improved animal slaughter procedure which results in relatively small amounts of blood draining from the animal once it has left the sticking area, thereby improving the cleanliness of the work floor, and reducing the risk of blood contamination.

It is a still further object of the present invention to provide an improved animal slaughter procedure which results in vastly improved productivity due to the ability of the workmen to carry out their work procedures on the dead animal far more effectively due to the relatively quick immobilisation of the muscles of the 15 animal.

i Broadly according to this invention therefore, there is provided a method of treatment of an animal during the slaughter thereof which includes the step of S••injecting pressure fluid into the cranial cavity of the animal in a manner so that the muscles of the animal are effectively immobilised. Conveniently the pressure fluid is filtered compressed air.

Desirably the compressed air is jetted into the cranial cavity of the animal using an injector device and which is effective to destroy its brain structure, and desirably also into the animal's spinal cavity so as to sever the fine nerve endings attached to the spinal cord of the animal, thereby completely immobilising its muscles. The step of air injection will normally be carried out after the animal has been stunned and which, in the case of a bolt gun, provides an opening which allows the nozzle of the injector to be inserted into the cranial cavity.

WO 00/27211 PCT/AU99/00983 3 More specifically according to this invention, there is provided a method of slaughtering animals including the steps of: stunning the animal, inserting an elongate nozzle into the cranial cavity of the animal and orientating same so that the nozzle is directed towards the spinal cavity, and admitting pressure fluid, eg compressed air, through the nozzle and into the cranial and spinal cavities of the animal in a number of short bursts, so as to destroy the brain structure and to expand the spinal cavity. Desirably, each burst is for a period of a few seconds.

Trials which have been carried out have shown that the compressed air discharge into the cranial cavity produces a brief period of stimulation, following which no further reflex stimulation occurs. The entry of the compressed air into the spinal cavity results in a pressure build up sufficient to crush the spinal cord and also tear the fine nerve endings off the spinal cord. Desirably the pressure needed to complete this procedure is in the order of 140 KPA. Preferably the pressure air is injected into the cranial cavity in two or three successive four second bursts.

The trials have also shown that following the compressed air discharge into the cranial cavity, the neck opening procedure (prior to the thoracic sticking) evokes no further flinching of the animal carcass, and similarly for the head removal (spinal transection) procedure.

Preferably the injection of compressed air is carried out after the animal has reached the point of irreversible insensibility.

In addition to the improved safety aspect provided by the method of this invention, the following advantages also apply: SUBSTITUTE SHEET (RULE 26)RO/AU WO 00/27211 PCT/AU99/00983 4 the amount of blood that is drained from the animal whilst still in the sticking area, is significantly increased, which of course means that there is less bleeding of the carcass once it leaves the sticking area. As air is injected, the body stiffens for a brief moment and pumps out a large amount of blood. Some of this blood would normally drain out of the body as it progresses around the kill floor and therefore would not be saved; (ii) a significant shortening in the time for transferring the bodies from the bleed chain to the legging chain, which allows the speed of the conveyor chain to be significantly increased with the knowledge that none of the workers will be accidentally kicked in these areas; (iii) the head of the animal is easier to skin because air seeps in between the skull and the hide; (iv) head meat can be removed from the bone easier because air is forced into the muscle seams; dropping tongues is easier due to the fact that as the air is forced up into the spine, it also causes the inside of the head (jaw area) to expand allowing more area for the tongue to be dropped; (vi) during the sawing procedure, normally the body of the animal twitches as the saw blade runs down the spine which makes difficult the saw operators task of keeping the saw in-line with the back bone. However, with the present invention, as a result of the nerve endings being severed, there is no twitching or flinching, thereby increasing the likelihood of a straight back bone cut being achieved; (vii) the injection of the pressure air, in being forced up the spine, penetrates the spinal cavity and seams the muscles around the neck area. In some cases, this results in the meat being lifted off the neck bones, which is of assistance to the hot neck boners; and (viii) provides a more consistent meat colour which is more appealing to the customer and beneficial to the meat industry. It will be appreciated that at the point of stimulation, all the muscles in the body are relaxed and the blood is able to flow SUBSTITUTE SHEET (RULE 26)RO/AU WO 00/27211 PCT/AU99/00983 freely out of the tense muscles. When the muscles are tense, the blood vessels will burst when the animal experiences spasms and this will cause meat discolouration a problem associated with existing slaughter procedures.

A preferred embodiment of the invention will now be described in more detail with reference to the accompanying drawing which shows an injector hand piece and nozzle which is used to inject pressure fluid into the cranial cavity of the animal.

According to this embodiment, an animal is first herded into a device such as a V-restrainer or knocking box where it is stunned using either a conventional mushroom-head stunner or a bolt gun. In the case of a mushroom-head stunner, the cranium of the animal is hit with such force that the head of the mushroom-head stunner in most cases penetrates the cranial cavity of the animal, while in the case of a bolt gun, the bolt penetrates the cranial cavity with relative ease leaving an almost perfect round hole with a diameter in the order of 10 mm.

The stunned animal is then shackled by placing a shackle chain connected to a roller around its rear right hock. The roller is then placed onto a section of rail and where a V-restrainer is used, it forwardly propels the animal out onto a dry landing table. A mechanised chain gathers the shackle roller and elevates the shackled animal up and onto a bleed rail which is suspended from the slaughter room ceiling.

In the case of a knocking box, a false floor or door opens and the animal rolls out onto its side so that it can be shackled. Next, an electric hoist lifts the animal up onto the bleed rail. The time taken from the point of the animal being stunned to being placed onto the bleed rail is a minimum of 15 seconds and a maximum of seconds.

SUBSTITUTE SHEET (RULE 26) RO/AU WO 00/27211 PCT/AU99/00983 6 Using the injector device 10 shown in the drawing, the elongate nozzle 11 of the injector device 10 is inserted into the cranial cavity of the animal via the damaged cranium which has resulted from the stunning procedure. The nozzle of the injector device is then elevated in the direction of the spinal cavity at the back of the animals head. The nozzle should be correctly positioned with at least 50 to 70 mm of its shaft inserted into the cranial cavity; however this will depend on the size of the animal being slaughtered. The trigger or button actuator on the injector device is then pressed so as to discharge compressed filtered air into the cranial cavity and through to the spinal cavity. Desirably pressure air is jetted into the cranial cavity for two or three successive bursts each of approximately four seconds. This causes the spinal cavity to expand and the air forces its way out between the cervical and thoracic vertebrae and into the seams between the muscles in the forequarter. The damage to the cranial cavity is such that any remaining brain structure is destroyed instantly the moment the pressure air is introduced into the cranial cavity. As the compressed air enters the spinal cavity, pressure build up is so great that is crushes the spinal cord and also tears the fine nerve endings off the spinal cord, thereby completely immobilising the muscles of the animal. Desirably the pressure needed to complete this procedure is in the order of 140 KPA.

The injector procedure produces a brief period of stimulation. After this stimulation period is complete, there is no reflex activity in the animal and this is evidenced by the observation that the neck opening procedure which is the next step in the slaughter process (and which is prior to the thoracic sticking) evokes no further flinching of the carcass, and similarly for the head removal (spinal transection) procedure.

Referring once again to the accompanying drawing, the injector device comprises a hand piece 12 which detachably connects to the elongate nozzle 11, the hand piece 12 incorporating a suitable one-way control valve 13 for controlling the SUBSTITUTE SHEET (RULE 26) RO/AU WO 00/27211 PCT/AU99/00983 7 delivery of compressed air through the nozzle 11, the compressed air being pumped through an air delivery hose 14 which at its downstream end connects to the inlet of the control valve 13 housed in the hand piece 12 while its upstream end connects to a compressor which delivers the filtered compressed air. The same compressor can be used as that which powers the air powered knives and other equipment on the floor.

The hand piece 12 also includes an actuating button 15 for actuating the control valve 13.

The elongate nozzle 11 has a shield 16 slidably fitted thereon for protection of the injector operator. Where the injector is being used to inject into the atlas join of the animal, the shield 16 would normally be located adjacent the forward end of the hand piece, while if the nozzle is inserted into the head of the animal, only 60 to mm of nozzle is needed and the shield 16 can be moved closer to the head of the animal to better protect the operator.

The nozzle 11 is provided with a conical tip end 17 to assist its penetration into the cranial cavity of the animal. The tip 17 is designed so that its edge can be readily sharpened.

It should of course be appreciated that the method of the present invention is not necessarily limited to the use of compressed air and any other suitable pressure fluid, eg jetted water, which does not pose an additional contamination risk to the quality of the meat of the animal, can be used. The use of compressed air is convenient given that an air compressor is already required for powering some of the equipment used by the slaughtermen.

A brief consideration of the above described embodiment will indicate that the invention provides for an extremely simple and effective treatment method for substantially eliminating the potentially dangerous reflex activity in animal carcasses SUBSTITUTE SHEET (RULE 26)RO/AU WO 00/27211 PCT/AU99/00983 8 during the slaughter thereof, and in turn the risk of slaughtermen being seriously injured during the slaughtering procedure.

SUBSTITUTE SHEET (RULE 26)RO/AU

Claims (9)

1. A method of treatment of an animal during the slaughter thereof which includes the step of injecting pressure fluid into the cranial cavity of the animal to effectively immobilise the muscles of the animal.

2. A method according to claim 1 wherein said pressure fluid is compressed air.

3. A method according to claim 2 wherein said compressed air is delivered at a pressure in the order 140 KPA.

4. A method according to any one of either claims 1 to 3 wherein said pressure fluid is injected into the cranial cavity and also the spinal cavity of the animal.

5. A method of slaughtering animals including the steps of: stunning the animal; inserting an elongate nozzle of an injector unit into the cranial cavity of the animal and orientating same so that the nozzle is directed towards the spinal cavity, 0 *.i and; admitting pressure fluid through the nozzle and into the cranial and spinal cavities of the animal in a number of short bursts, so as to destroy the brain structure of the animal and to expand the spinal cavity thereof.

6. A method according to claim 5 wherein said p urssure fluid is compressed air.

7. A method according to either claim 5 or 6 wherein each said burst is for a period of a few seconds.

8. A method according to any one of claims 5, 6 or 7 wherein said compressed air is injected into said cranial and spinal cavities of the animal at a pressure in the order of 140 KPA.

9. A method according to any one of claims 5 to 8 wherein the step of stunning the animal is effected by means of a bolt gun. A method according to claim 9 wherein the elongate nozzle is inserted into the opening formed by said bolt gun. Dated this 11 th day of July, 2002. RICHARD SYDNEY WIGG and I KELIE ANN WIGG S: 15 By their Patent Attorneys MADDERNS 0* o* 0Ooo