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Gas mixtures for anaesthesia and euthanasia in broiler chickens

Published online by Cambridge University Press:  18 September 2007

Anton Coenen
Affiliation:
NICI, Department of Psychology, University of Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlandsand
Annika Smit
Affiliation:
NICI, Department of Psychology, University of Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlandsand
Li Zhonghua
Affiliation:
Department of Pharmacology, School of Basic Medical Sciences, Beijing Medical University, Beijing 100083, P.R., China
Gilles Van Luijtelaar
Affiliation:
NICI, Department of Psychology, University of Nijmegen, P.O. Box 9104, 6500 HE Nijmegen, The Netherlandsand
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Abstract

The aim of this experiment was to develop an alternative, acceptable and humane method for killing broiler chickens. Our main premise was that euthanasia should preferably take place in two steps. Firstly, the bird should be anaesthetised quickly and completely using appropriate procedures and, secondly, the anaesthetised bird should be killed as quickly as possible. Two gas mixtures were considered for anaesthesia: 40% carbon dioxide with 30% oxygen and 30% nitrogen or 40% carbon dioxide with 15% oxygen and 45% nitrogen. It was found that the birds' behaviour in the high oxygen environment was less disturbed, with less agitation and distress being demonstrated. For this reason, the high oxygen condition is to be preferred and this anaesthetic was used in the second part of the experiment. The bird was exposed for one minute to 40% carbon dioxide, 30% oxygen and 30% nitrogen (anaesthesia) and then to 80% carbon dioxide, 5% oxygen and 15% nitrogen (euthanasia). This condition was compared with the frequently used eutha- nasia condition involving argon. The use of argon is based on the idea that it produces fast suffocation of the birds. The argon condition consisted of 30% carbon dioxide and 60% argon in air with less than 2% oxygen and 8% nitrogen. The chickens died significantly later in the oxygen/carbon dioxide condition than in the argon condition. Judgements of death were based on both the pattern of electrical brain activity and on heart rate. The time taken for the chickens to become unconscious, as judged from the isolectric electroencepha- logram, was also significantly longer in the oxygen/carbon dioxide condition than in the argon condition. However, in the argon condition the birds immediately showed strong signs of agitation and distress, particularly intense and heavy muscle contractions, whereas these signs were less pronounced in the oxygen/carbon dioxide condition. It is concluded that, although the chickens lost consciousness sooner and also died sooner in the argon condition, there are good reasons to prefer the oxygedcarbon dioxide condition because it results in less disturbed behaviour and the birds exhibited milder signs of distress during the period when consciousness cannot be fully excluded. Hence, a milder death, taking somewhat longer, is preferred to a quicker but more distressing death. Finally, the oxygen/carbon dioxide condition was repeated with turkeys when, in general, the results were the same.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2000

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References

Anton, F., Euchner, I. and Handwerker, H.O. (1992) Psychophysiological examination of pain induced by defined carbon dioxide pulses applied to the nasal mucosa. Pain 49: 5360CrossRefGoogle Scholar
AMERICAN VETERINARY MEDICAL ASSOCIATION (AVMA) (1993) Report of the AVMA Panel on Euthanasia. Journal of the American Veterinary Medical Association 202: 230249Google Scholar
Cain, W.S. and Murphy, C.L. (1980) Interaction between chemoreceptive modalities of odour and irritation. Nature 284: 255257CrossRefGoogle ScholarPubMed
Clifford, D.H. (1984) Preanesthesia, anesthesia, analgesia and euthanasia. In: Lubvratory Animal Medicine (Fox, J.G., Cohen, B.J. and Loew, F.M., Eds), Academic Press, Orlando, USA, pp. 527562CrossRefGoogle Scholar
Coenen, A.M.L., Drinkenburg, W.H.I.M., Hoenderken, R. and Van Luijtelaar, E.L.J.M. (1995) Carbon dioxide euthanasia in rats: oxygen supplementation minimizes signs of agitation and asphyxia. Laboratoy Animals 29: 262268CrossRefGoogle ScholarPubMed
Forslid, A. (1987) Transient neocortical, hippocampal and amygdaloid EEG silence induced by one minute inhalation of high concentration carbon dioxide in swine. Acta Physiologica Scandinavica 130: 10CrossRefGoogle ScholarPubMed
Forslid, A., Ingvar, M., Rosen, I. and Ingvar, D.H. (1986) Carbon dioxide narcosis: influence of short-term high concentration carbon dioxide inhalation on EEG and cortical evoked response in the rat. Acta Physiologica Scandinavica 127: 281287CrossRefGoogle ScholarPubMed
Freed, D.L.J. (1983) Carbon dioxide euthanasia. Nature 304: 482CrossRefGoogle Scholar
Kobal, G. (1985) Pain-related electrical potentials of the human nasal mucosa by chemical stimulation. Pain 22: 151163CrossRefGoogle ScholarPubMed
Komai, M. and Bryant, B.P. (1993) Acetazolamide specifically inhibits lingual trigeminal nerve responses to carbon dioxide. Brain Research 612: 122129CrossRefGoogle ScholarPubMed
NATIONAL RESEARCH COUNCIL (1992) Euthanasia. In: Recognition and Alleviation of Pain and Distress in Laboratory Animals. A Report of the Institute of Laboratory Animal Resources Committee on Pain and Distress in Laboratory Animals, National Academy Press, Washington DC, USA, pp. 102116Google Scholar
Paton, W.D.N. (1983) Is carbon dioxide euthanasia humane? Nature 305: 268CrossRefGoogle Scholar
Raj, A.B.M. (1996) Aversive reactions of turkeys to argon, carbon dioxide and a mixture of carbon dioxide and argon. Veterinary Record 138: 592593CrossRefGoogle Scholar
Raj, A.B.M. and Whittington, P.E. (1995) Euthanasia of day-old chicks with carbon dioxide and argon. Veterinary Record 136: 292294CrossRefGoogle ScholarPubMed
Stevens, J.C. and Cain, W.S. (1986) Aging and the perception of nasal irritation. Physiology and Behaviour 37: 323328CrossRefGoogle ScholarPubMed
Thurauf, N., Ditterich, W. and Kobal, G. (1994) Different sensitivity of pain related chemosensory potentials evoked by stimulation with carbon dioxide, tooth pulp event-related potentials, and acoustic event-related potentials to the tranquilizer diazepam. British Journal of Clinical Pharmacology 38: 545555CrossRefGoogle Scholar