Humane stun and dispatch

Abstract

A method for the humane stun and dispatch (HSD) of animals such as rodents, broilers and even larger animals using a device that includes one or more magnetic field generators based on a dielectric ri

Description

Description HUMANE STUN AND DISPATCH Technical Field

[0001] The present invention relates to use of a magnetic field (B-field) for the humane euthanasia and / or stun and dispatch of various animals. Background Art

[0002] Since 1979, the stunning of livestock has been mandatory in the EU, although each member state is free to grant its own exemptions for religious reasons. In the UK, the Humane Slaughter Association and the RSPCA have easily accessible information on-line about the humane transportation, stunning and slaughter of animals for human consumption.

[0003] Common stunning methods include electrical stunning, captive-bolt stunning or the use of carbon dioxide gas. Captive-bolt stunning devices where the bolt enters the brain (penetrative bolt) will result in greater stunning efficiency than non-penetrative stunners (‘mushroom-headed’ bolt) that rely on the percussive blow on its own to achieve immediate insensibility.

[0004] GB 25925244A relates to a system for wireless power transfer of electrical power of 100s of kW / module at over 90% efficiency by use of dielectric ring resonators (DRRs). Wireless power transfer relates to transferring electrical energy across a spatial region from a transmitter to a receiver. Although paragraph

[0021] alludes to use of this technology in humane stun and dispatch of vertebrates such as broilers and sheep in slaughterhouses and which is Halal compliant no details about this possible application are provided. This document is primarily concerned with application of the technology described to the charging of electric vehicles (EVs). Summary of invention

[0005] The present invention provides a method for the humane stun and dispatch (HSD) of animals such as rodents, broilers and even larger animals using a device that includes one or more magnetic field generators based on a dielectric ring resonator (DRR) to generate a strong magnetic B-field to stun or dispatch a target, an animal brain for example, without affecting a remaining part of the animal. Thus, the brain of the animal is simply a Load entered into the device. The device used in the method of the present invention is aimed at maximising the magnetic B-field and minimising the electric E-field. Magnetic induction heating relies on the electrical conductivity of a material, whereas dielectric heating relies on the permittivity and loss tangent of the material. Bone has a low electrical conductivy and high permittivity and loss tangent and is therefore not affected by magnetic induction heating. Another important feature of the invention is that it uses the reactive near electromagnetic field (near-field), which is less than about half a wavelength of the electromagnetic energy from the source. Whereas the Prior Art identified uses the radiative far electromagnetic field (far-field), which is a distance greater than about half a wavelength of the electromagnetic energy from the source. Electromagnetic absorption in the near-field is dominated by magnetic effects (i.e. induction heating), whereas in the far-field it is dominated by electric effects (i.e. dielectric heating). Where methods use far-field devices, dielectric heating will dominate, which cause excessive heating of bone for HSD. Reactive near-field devices do not tend to radiate energy to the surroundings, whereas with far-field devices all the energy is radiated. The method has two modes of action: a static mode where a user inserts a Load into the device and a moving mode where the Load is moved relative to the device. The applications for this technique are very broad, but the inventors are developing the idea specifically for the humane stun and / or dispatch of lab rodents, boilers and even extending to larger animals. There is an urgent need for more humane dispatch methods for animals, especially poultry in slaughterhouses. Stunning is commonly used to render the animal unconscious prior to and during exsanguination, preventing unnecessary suffering. Most poultry slaughtered in the UK are stunned using controlled atmospheric stunning (CAS) with CO2, or by the electrical water bath method. Yet, it's recognised that exposure to CO2 can cause pain, anxiety, dyspnoea and nausea, and have high capital and running costs. Electrical water bath stunning is widely recognised as having significant welfare issues. Furthermore, there is a big consumer-driven pull to increase health and welfare of production animals, and the slaughterhouse industry want to respond. The DRR device used in the method according to the invention is an alternative, cheaper, contactless humane stun and / or dispatch method based on radio- frequency (RF) magnetic B-field induction heating of the brain for rapid dispatch of slaughter weight broilers. RF magnetic B-field induction may also heat the brain to provoke recoverable unconsciousness (stunning) for the Halal markets.

[0012] This method and associated DRR device can also be used for humane euthanasia of lab rodents. In the UK, 10 million lab rodents per year are killed, which make up the vast majority of research animals. Current techniques for killing them include inhalation methods, such as chambers that fill with carbon dioxide or anaesthetic gases, and injecting barbiturates. Physical methods include cervical dislocation (breaking of the neck), or decapitation with specialist rodent guillotines.

[0013] The device including a DRR used in the method according to the invention may produce an electromotive density (frequency x peak B-field) A = 6642 MHz.mT with only 330 W of power, which is sufficient to heat a rodent or chicken brain by enough to cause a coma or death in under 1 second. Brief description of drawings

[0014] The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

[0015] Fig. 1a illustrates a general device used in the method according to the invention having a ring of dielectric material 10 and an excitation coil 20 housed within a cavity 30.

[0016] Fig. 1b shows the magnetic flux density 15 around the dielectric ring 10 with the arrow volume providing an indication of the size of the magnetic flux density 15.

[0017] Fig. 2a shows a mouse head 64 in a dielectric ring 10 (cavity not shown), part of a benchtop, pass through DRR device 1.

[0018] Fig. 2b shows a picture of the mouse skull 66 with the heating plot on the right- hand side indicating the brain 50 temperature distribution caused by the strong B- field generated by the dielectric ring shown in Fig. 1a operating at a frequency of 915 MHz.

[0019] Fig. 2c shows a picture of a chicken / broiler skull 68 with the heating plot on the right-hand side indicating the brain 50 temperature distribution caused by a strong B-field generated by a similar dielectric ring to that shown in the earlier Fig. 1a operating at a frequency of 168 MHz. Description of embodiments

[0020] Figures 1a and 1b illustrate the basic concept of a pass-through DRR 1. A dielectric ring 10 is resonating at its fundamental frequency and uses the strong magnetic field (B-field) generated in the centre of the ring. The dielectric ring 10 is driven by an excitation means 20 and needs to be housed in a cylindrical cavity 30 having an inner wall surface 35, to prevent power loss due to radiation, although the cavity 30 may be open at one or both ends. Note: The DRR 1 comprises the cavity 30, excitation means 20 and the dielectric ring 10. Figure 2a provides an example induction method for humane euthanasia of lab rodents using a bench-top, mains-driven pass-through DRR 1. The cavity is sealed at one end but can have an opening at the other end into which a live lab rodent 64 is inserted (for example in a small bag or cardboard box) into the centre of the pass-through dielectric ring before turning the device on. A polystyrene insert can be used to correctly locate the rodent 64 in the centre of the ring. Alternatively, a small conveyor belt can transport the rodent 64 through the device. As shown in Fig. 2b, the mouse brain temperature is 50°C (14°C temperature rise) after 1 s heating at an input power of 188 W at a frequency of 915 MHz (A = 680 MHz.mT). A 14 °C temperature rise of the brain 50 is more than sufficient to euthanise the rodent 64. No part of the rodent 64 is heated to a point which would cause a smell of cooking, or other signs of burning or damage. It is thus a cheap, clean method of euthanasia. The same magnetic induction method is also suitable for the HSD of chickens (broilers) in a slaughterhouse. The DRR 1 is fundamentally the same as that shown in Fig. 1a but as apparent to those skilled in the art it will need to be adapted to fit the DRR device used in the method according to the invention into a production line. Fig. 2c shows a chicken (broiler) skull 68 with brain 50, whose temperature is 46°C (10°C temperature rise) after 1 s heating at 300 W power at 168 MHz (A = 360 MHz.mT). A 7°C temperature rise of the brain 50 is sufficient to induce a recoverable coma (stun), and 10°C temperature rise sufficient to dispatch the chicken. A recoverable coma is needed for Halal markets.

Claims

Claims 1. A humane method of rapid stun and / or dispatch of animals using a DRR (1) having a dielectric ring (10) in which a strong radio-frequency (RF) magnetic B-field is generated in the centre of the ring, wherein the magnetic B-field causes induction heating of the brain (50) of the animal.

2. A humane method of rapid stun of animals according to claim 1, wherein the brain (50) of the animal is heated to provoke recoverable unconsciousness prior to dispatch.

3. A humane method of rapid stun and dispatch according to claim 1, for the euthanasia of lab rodents (64) using a bench-top, mains-driven pass-through DRR (1).

4. A humane method of rapid stun and dispatch according to claim 3, wherein a live lab rodent is inserted into a small bag or cardboard box having a polystyrene insert to correctly locate the rodent in the centre of a pass-through DRR (1).

5. A humane method of rapid stun and dispatch according to claim 4, wherein the rodent (64) is transported through the DRR (1) on a conveyor belt.

6. A humane method of rapid stun and dispatch of chickens in a slaughterhouse, wherein the pass-through DRR (1) is adapted to fit into a production line.

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