Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-28T00:28:45.809Z Has data issue: false hasContentIssue false

Recent developments in stunning and slaughter of poultry

Published online by Cambridge University Press:  01 September 2006

A.B.M. RAJ
Affiliation:
School of Clinical Veterinary Science, University of Bristol, LangfordBS40 5DU, United Kingdom E-mail: M.Raj@bristol.ac.uk
Get access

Abstract

A requirement under humane slaughter regulation is that stunning methods should induce immediate loss of consciousness and sensibility. If the onset of unconsciousness is not immediate, the induction of unconsciousness with a stunning method should not cause in animals avoidable anxiety, fear, pain, distress or suffering. The duration of unconsciousness induced by a stunning procedure must be longer than the sum of time that lapses between the end of stun and the time to onset of death. Since the effect of a stunning method is momentary, the onus of preventing resumption of consciousness thereafter relies on the efficiency of slaughter procedure; i.e. the prompt and accurate severance of blood vessels supplying oxygenated blood to the brain. Electrical water baths and gas or controlled atmospheres are commonly used for stunning poultry under commercial conditions. The electrical waveforms (sine wave alternating current or pulsed direct current) and frequencies (Hz) employed to stun poultry and the amount of current applied to individual birds in a water bath stunner widely varies. Rationalisation of electrical variables is urgently warranted. Varieties of gas mixtures have been proposed or used for stunning or killing poultry in crates or conveyors however the bird welfare implications have not been communicated effectively to facilitate progress. This review deals with the efficacy of electrical variables used in the water baths and of slaughter methods, and the relative merits of different gas mixtures used for stunning or killing broilers.

Type
Review Article
Copyright
Copyright © World's Poultry Science Association 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

BANZETT, R. and MOOSAVI, S.H. (2001) Dyspnoea and pain: similarities and contrasts between two very unpleasant sensations. American Pain Society Bulletin 11(2). Can be accessed at www.ampainsoc.org/pub/bulletin/mar01/upda1.htm.Google Scholar
BENACKA, R. and TOMORI, Z. (1995) The sniff-like aspiration reflex evoked by electrical stimulation of the nasopharymx. Respiratory Physiology 102: 163174.CrossRefGoogle Scholar
BEYSSEN, C., BABILE, R. and FERNANDEZ, X. (2004) Electrocorticogram spectral analysis and somatosensory evoked potentials as tools to assess electrical stunning efficiency in ducks. British Poultry Science 45: 409415.CrossRefGoogle ScholarPubMed
COATES, E.L., KNUTH, S.L. and BARTLETT, D. Jr. (1996) Laryngeal CO2 receptors: influence of systemic PCO2 and carbonic anhydrase inhibition. Respiration Physiology 104: 5361.CrossRefGoogle ScholarPubMed
COENEN, A., SMIT, A., ZHONGHUA, L. and VAN LUIJTELAAR, G. (2000) Gas mixtures for anaesthesia and euthanasia in broiler chickens. World's Poultry Science Journal 56: 225234.CrossRefGoogle Scholar
DELL, P., HUGELIN, A. and BONVALLET, M. (1961) In: Cerebral Anoxia and the Electroencephalogram, edsGustaut, H. and Meyer, J.S., pp. 46. Springfield, IL: Charles C Thomas.Google Scholar
ERNSTING, J. (1965) The effect of anoxia on the central nervous system. In: A Text Book of Aviation Physiology, pp. 271289, ed. Gillies, J.A.. Pergamon Press.Google Scholar
ERLICHMAN, J.S. and LEITER, J.C. (1997) Comparative aspects of central CO2 chemoreception. Respiration Physiology 110: 177185.CrossRefGoogle ScholarPubMed
EUROPEAN COMMUNITY (1993) Directive 93/119/EC on the protection of animals at the time of slaughter or killing. European Community Official Journal 340: 2134.Google Scholar
EUROPEAN FOOD SAFETY AUTHORITY (2004) Welfare aspects of animal stunning and killing methods. Can be accessed at www.efsa.eu.int/science/ahaw/ahaw_opinions.Google Scholar
EUROPEAN FOOD SAFETY AUTHORITY (2005) Aspects of the biology and welfare of animals used for experimental and other scientific purposes. Annex to the EFSA Journal 292: 1136.Google Scholar
FAWC (1982) Report on the welfare of poultry at the time of slaughter. Present address: Farm Animal Welfare Council, 1A Page Street, London, SW1P 4PQ, UK.Google Scholar
FAWC (2003) Welfare of Farmed Animals at Slaughter or Killing (Red Meat Animals). Can be accessed at www.fawc.org.Google Scholar
FEDDE, M.R., NELSON, P.I. and KUHLMANN, W.D. (2002) Ventilatory sensitivity to changes in inspired and arterial carbon dioxide partial pressures in the chicken. Poultry Science 81: 869876.CrossRefGoogle ScholarPubMed
HEMPLEMAN, S.C. and BEBOUT, D.E. (1994) Increased venous PCO2 enhances dynamic responses of avian intrapulmonary chemoreceptors. American Journal of Physiology Regulatory Integrative Comparative Physiology 266: R15R19.CrossRefGoogle ScholarPubMed
HEMPLEMAN, S.C., POWELL, F.L. and PRISK, G.K. (1992) Avian arterial chemoreceptor responses to steps of CO2 and O2. Respiration Physiology 90: 325340.CrossRefGoogle ScholarPubMed
HEMPLEMAN, S.C., RODRIGUEZ, T.A., BHAGAT, Y.A. and BEGAY, R.S. (2000) Benzolamide, acetazolamide, and signal transduction in avian intrapulmonary chemoreceptors. American Journal of Physiology Regulatory Integrative Comparative Physiology 279: 19881995.CrossRefGoogle ScholarPubMed
HOENDERKEN, R., VAN LOGTESTJIN, J.G., SYBESMA, W. and SPANJAARD, W.J.M. (1979) Kohlendioxid-Betabung von Schlachtschweinen. Fleischwirtschaft 59: 15721578.Google Scholar
INGLING, A.L. and KUENZEL, W.J. (1978) Electrical terminology, measurement and units associated with the stunning technique in poultry processing plants. Poultry Science 57: 127133.CrossRefGoogle Scholar
ITURRIAGA, R., LAHIRI, S. and MOKASHI, A. (1991) Carbonic anhydrase and chemoreception in the cat carotid body. American Journal of Physiology Cell Physiology 261: C565C573.CrossRefGoogle ScholarPubMed
JODKOWSKI, J.S., GUTHERIE, R.D. and CAMERON, W.E. (1989) The activity pattern of phrenic motoneurones during the aspiration reflex: an intracellular study. Brain Research 505: 187194.CrossRefGoogle ScholarPubMed
KUENZEL, W.J. and WATHERS, J.H. (1978) Heart rate, blood pressure, respiration, and brain waves of broilers as affected by electrical stunning and bleed out. Poultry Science 57: 655659.CrossRefGoogle Scholar
LAMBOOIJ, E., GERRITZEN, M.A., ENGEL, B., HILLEBRAND, S.J.W., LANKHAAR, J. and PIETERSE, C. (1999) Behavioral responses during exposure of broiler chickens to different gas mixtures. Applied Animal Behaviour Science 62: 255265.CrossRefGoogle Scholar
LUDDERS, J.W. (2001) Inhaled anaesthesia for birds. In: Recent Advance in Veterinary Anesthesia and Analgesia: Companion Animals, Gleed, R D and Ludders, J W(Eds)International Veterinary Information Service, Itheca, New York, USA. Can be accessed at www.ivis.org.Google Scholar
LUKATCH, H.S., ECHON, R.M., MACIVER, M.B. and WERCHAN, P.M. (1997) G-force induced alterations in rat EEG activity: a quantitative analysis. Electroencephalography and Clinical Neurophysiology 103: 563573.CrossRefGoogle ScholarPubMed
MCKEEGAN, D.E.F., DEMMERS, T.G.M., WATHERS, C.M. and JONES, R.B. (2003) Chemosensitivity responses to gaseous pollutants and carbon dioxide: implications for poultry welfare. Poultry Science 82 (supplement 1): 16.Google Scholar
MANNING, H.L. and SCHWARTZSTEIN, R.M. (1995) Pathophysiology of Dyspnoea. New England Journal of Medicine 333 (23): 15471553.CrossRefGoogle Scholar
MCINTYRE, C.C. and GRILL, W.M. (2002) Extracellular stimulation of central neurones: Influence of stimulus waveform and frequency on neuronal output. Journal of Neurophysiology 88: 15921604.CrossRefGoogle ScholarPubMed
MILSOM, W.K. (2001) Abstract 1.5. Phylogeny of central CO2/pH chemoreception in vertebrates. In: Neural Control of Breathing. An Official Satalite of the International Congress of Physiological Societies (IUPS) 2001, Rotorua, New Zealand, 14 September 2001. Can be accessed at http://respiratoryresearch.com/content/2/S1.Google Scholar
MOUCHONIÈRE, M., LE POTTIER, G. and FERNANDEZ, X. (1999a) The effect of current frequency during waterbath stunning on the physical recovery and rate and extent of bleed out in turkeys. Poultry Science 77: 485489.CrossRefGoogle Scholar
MOUCHONIÈRE, M., LE POTTIER, G. and FERNANDEZ, X. (1999b) The effect of current frequency during waterbath stunning on the physical recovery and rate and extent of bleed out in turkeys. Poultry Science 77: 485489.CrossRefGoogle Scholar
MOUCHONIÈRE, M., LE POTTIER, G. and FERNANDEZ, X. (2000) Effect of current frequency during electrical stunning in a water bath on somatosensory evoked responses in turkey's brain. Research in Veterinary Science 69: 5355.CrossRefGoogle Scholar
MU, Q., BOHNING, D.E., NAHAS, Z., WALKER, J., ANDERSON, B., JOHNSON, K.A., DENSLOW, S., LOMAREV, M., MOGHADAM, P., CHAE, J-H. and GEORGE, M.S. (2004) Acute vagus nerve stimulation using different pulse widths produces varying brain effects. Biological Psychiatry 55: 816825.CrossRefGoogle ScholarPubMed
RAJ, A.B.M. (1996) Aversive reactions of turkeys to argon, carbon dioxide, and a mixture of carbon dioxide and argon. Veterinary Record 138: 592593.CrossRefGoogle Scholar
RAJ, A.B.M. (1997) Gas stunning broilers: welfare and product quality. In: Alternative Stunning Methods for Poultry, Lambooij, E.(Ed)ID-DLO Institute for Animal Science and Health publication number 97.037.Google Scholar
RAJ, A.B.M. (2003) A critical appraisal of electrical stunning in chickens. World's Poultry Science Journal 59: 8998.CrossRefGoogle Scholar
RAJ, A.B.M. and GREGORY, N.G. (1990) Effect of rate of induction of carbon dioxide anaesthesia on the time to onset of unconsciousness and convulsions. Research in Veterinary Science 49: 360363.Google Scholar
RAJ, A.B.M. and GREGORY, N.G. (1995) Welfare implications of gas stunning pigs 1. Determination of aversion to the initial inhalation of carbon dioxide or argon. Animal Welfare 4: 273280.CrossRefGoogle Scholar
RAJ, A.B.M. and GREGORY, N.G. (1996) Welfare implications of gas stunning pigs 2. Stress of induction of anaesthesia. Animal Welfare 5: 7178.CrossRefGoogle Scholar
RAJ, A.B.M. and O'CALLAGHAN, M. (2004a) Effect of amount and frequency of stunning currents on the electroencephalogram and somatosensory evoked potentials in broilers. Animal Welfare Journal 13: 159170.CrossRefGoogle Scholar
RAJ, A.B.M. and O'CALLAGHAN, M. (2004b) Effects of electrical water bath stunning current frequencies on the spontaneous electroencephalogram and somatosensory evoked potentials in hens. British Poultry Science Journal 45: 230236.CrossRefGoogle ScholarPubMed
RAJ, A.B.M., GREGORY, N.G. and WOTTON, S.B. (1991) Changes in the somatosensory evoked potentials and spontaneous electroencephalogram of hens during stunning in argon-induced anoxia. British Veterinary Journal 147: 322330.CrossRefGoogle ScholarPubMed
RAJ, A.B.M., O'CALLAGHAN, M. and KNOWLES, T.G. (2006a) The effects of amount and frequency of sine wave alternating current used in water bath stunning and neck–cutting methods on electroencephalograms in broilers. Animal Welfare 15: 718.CrossRefGoogle Scholar
RAJ, A.B.M., O'CALLAGHAN, M. and HUGHES, S.I. (2006b) The effects of amount and frequency of a pulsed direct current used in water bath stunning and neck–cutting methods on electroencephalograms in broilers. Animal Welfare 15: 19-19-24.Google Scholar
RAJ, A.B.M., O'CALLAGHAN, M. and HUGHES, S.I. (2006c) The effects of pulse width of a direct current used in water bath stunning and of slaughter methods on spontaneous electroencephalograms in broilers. Animal Welfare 15: 2530.CrossRefGoogle Scholar
RICHERSON, G.B. (1995) Response to CO2 of neurons in the rostral ventral medulla in vitro. Journal of Neurophysiology 73: 933944.CrossRefGoogle ScholarPubMed
TEHOVNIK, E.J. (1996) Electrical stimulation of neural tissue to evoke behavioural responses. Journal of Neuroscience Methods 65: 117.CrossRefGoogle Scholar
SCHUTT-ABRAHAM, I., WORMUTH, H-J., FESSEL, J. and KNAPP, J. (1983) Electrical stunning of poultry in view of animal welfare and meat production. In: Eikelenboom, G. (ed) Stunning of Animals for Slaughter, pp. 154. Martinus Nijhoff: The Hague, The Netherlands.Google Scholar
TSCHORN, R.R. and FEDDE, M.R. (1974) Effects of carbon monoxide on avian intrapulmonary carbon dioxide-sensitive receptors. Respiration Physiology 20: 313324.CrossRefGoogle ScholarPubMed
WEBSTER, A.B. and FLETCHER, D. (2004) Assessment of the aversion of hens to different gas atmospheres using an approach-avoidance test. Applied Animal Behaviour Science 88: 275287.CrossRefGoogle Scholar