Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-26T07:25:53.555Z Has data issue: false hasContentIssue false
  • English
  • Français

Assessment of Return to Consciousness After Electrical Stunning in Lambs

Published online by Cambridge University Press:  11 January 2023

A Velarde ,
J L Ruiz-de-la-Torre ,
C Roselló ,
E Fàbrega ,
A Diestre  and
X Manteca
A Velarde
Affiliation:
Centre de Tecnologia de la Cam, Institut de Recerca i Tecnologia Agroalimentàries, Granja Camps i Armet, 17121 Monells (Girona), Spain
J L Ruiz-de-la-Torre
Affiliation:
Unitat de Fisiologia Animal, Facultat de Veterinària, Universität Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
C Roselló
Affiliation:
Unitat de Fisiologia Animal, Facultat de Veterinària, Universität Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
E Fàbrega
Affiliation:
Unitat de Fisiologia Animal, Facultat de Veterinària, Universität Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
A Diestre
Affiliation:
Centre de Tecnologia de la Cam, Institut de Recerca i Tecnologia Agroalimentàries, Granja Camps i Armet, 17121 Monells (Girona), Spain
X Manteca*
Affiliation:
Unitat de Fisiologia Animal, Facultat de Veterinària, Universität Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
*
‡ Contact for correspondence and requests for reprints: xavier.manteca@uab.es
Get access Rights & Permissions [Opens in a new window]

Abstract

The return to consciousness of 24 electrically stunned lambs was assessed by measurement of physiological reflexes and electroencephalography (EEG) recordings. The physical activity of the lambs after head-only electrical stunning included one tonic phase and two clonic phases. The tonic phase began immediately after the stun and ended 10 s after the stun; the first clonic phase started immediately after the tonic phase and ended 36 s after the stun, and the second clonic phase started immediately after the first clonic phase and ended 70 s after the stun. During the tonic phase and the first clonic phase, electrical activity recordings of the brain showed a dramatic increase in the relative power spectra of alpha and beta frequencies. Both frequencies returned to pre-stun levels with the end of the first clonic phase. During the second clonic phase, the relative power spectrum of theta frequency was higher than that before stunning. These results suggest that during the tonic phase and the first clonic phase, the animal was unconscious, whereas during the second clonic phase the return of some conscious function began. Spontaneous breathing returned at about 29 s post-stun, whereas the corneal reflex returned at about 38 s. It is therefore suggested that the return of spontaneous breathing is the safest indicator that the animal is close to recovering consciousness.

Keywords

animal welfareEEGphysiological reflexessheepslaughterstunning
Type
Research Article
Information
Animal Welfare , Volume 11 , Issue 3 , August 2002 , pp. 333 - 341
Copyright
© 2002 Universities Federation for Animal Welfare

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

Anil, M H and McKinstry, J L 1991 Reflexes and loss of sensibility following head-to-back electrical stunning in sheep. Veterinary Record 128: 106–107CrossRefGoogle ScholarPubMed
Bager, F, Shaw, F D, Tavener, A, Loeffen, M P F and Devine, C E 1990 Comparison of EEG and ECG for detecting cerebrocortical activity during slaughter of calves. Meat Science 27: 211–225CrossRefGoogle Scholar
Bager, F, Braggins, T J, Devine, C E, Graafhuis, A E, Mellor, D J, Tavener, A and Upsdell, M P 1992 Onset of insensibility at slaughter in calves: effects of electroplectic seizure and exsanguination on spontaneous electrocortical activity and indices of cerebral metabolism. Research in Veterinary Science 52: 162–173CrossRefGoogle ScholarPubMed
Cook, C J, Devine, C E, Tavener, A and Gilbert, K V 1992 Contribution of amino acid transmitters to epileptiform activity and reflex suppression in electrically head stunned sheep. Research in Veterinary Science 52: 48–56CrossRefGoogle ScholarPubMed
Cook, C J, Devine, C E, Gilbert, K V, Smith, D D and Maasland, SA 1995 The effect of electrical head-only stun duration on electroencephalographic-measured seizure and brain amino acid neurotransmitter release. Meat Science 40: 137–147CrossRefGoogle ScholarPubMed
Council Directive 93/119/EC of 22 December 1993 on the protection of animals at the time of slaughter or killing. Official Journal of the European Communities L340, p 0021–0034Google Scholar
Croft, P G 1952 Problem of electrical stunning. The Veterinary Record 64: 255–258Google Scholar
Croft, P G and Hume, C W 1956 Electric stunning of sheep. The Veterinary Record 68: 318–321Google Scholar
Devine, C E, Gilbert, K V, Graafhuis, A E, Tavener, A, Reed, H and Leigh, P 1986 The effect of electrical stunning and slaughter on the electroencephalogram of sheep and calves. Meat Science 1 7: 267–281CrossRefGoogle Scholar
Gregory, N G 1993 Euthanasia: the assessment of welfare and scientific aspect. In: Alternative Methods in Toxicology, Volume 11. Proceedings of the World Congress on Alternatives and Animal Use in the Life Science. Mary Ann Liebert Inc: New York, USAGoogle Scholar
Gregory, N G 1998 Physiology of stress, distress, stunning and slaughter. In: Animal Welfare and Meat Science pp 64–92. CAB International: Boston, USAGoogle Scholar
Gregory, N G and Wotton, S B 1984 Sheep slaughtering procedures. 1. Survey of abattoir practice. British Veterinary Journal 140: 281–286CrossRefGoogle Scholar
Gregory, N G and Wotton, S B 1985 Sheep slaughtering procedures. 4. Responsiveness of the brain following electrical stunning. British Veterinary Journal 141: 74–81CrossRefGoogle Scholar
Gregory, N G and Wotton, S B 1988 Sheep slaughtering procedures. 5. Responsiveness to potentially painful stimuli following electrical stunning. British Veterinary Journal 144: 573–580CrossRefGoogle Scholar
Hoenderken, R 1978 Electrical stunning of pigs for slaughter. PhD Thesis, State University, Utrecht, The NetherlandsGoogle Scholar
Lambooy, E 1982 Stunning of sheep. Meat Science 6: 123–135CrossRefGoogle ScholarPubMed
Martin, P and Bateson, P 1986 Measuring Behaviour: An Introductory Guide. Cambridge University Press: Cambridge, UKGoogle Scholar
Raj, ABM 1999 EEG in assessment of animal welfare during stunning of animals for slaughter. In: Proceedings of the International Workshop on Stunning Systems for Pigs and Animal Welfare pp 1–5. Danish Meat Research Institute: Billund, DenmarkGoogle Scholar
Ruckebush, Y, Malbert, C H and Baha, F 1987 Activité electrocorticale qauantifiée et perte de vigilance chez le chien et le mouton. Revue de Medicine Véterinaiere 138: 325–332 [Title translation: Quantification of electrocortical activity and loss of vigilance in dogs and sheep]Google Scholar
Velarde, A, Ruiz-de-laTorre, J L, Stub, C, Diestre, A and Manteca, X 2000 Factors affecting the effectiveness of head-only electrical stunning in sheep. The Veterinary Record 147: 40–43CrossRefGoogle ScholarPubMed