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The effect of electrical head-to-chest stunning on the EEG in sheep

Published online by Cambridge University Press:  01 January 2023

A Mason ,
E Tolo ,
L Hektoen  and
HA Haga
A Mason*
Affiliation:
Animalia AS (Norwegian Meat and Poultry Research Institute), PO Box 396, Økern, 05 13, Oslo, Norway
E Tolo
Affiliation:
Animalia AS (Norwegian Meat and Poultry Research Institute), PO Box 396, Økern, 05 13, Oslo, Norway
L Hektoen
Affiliation:
Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Pb 369 Sentrum, 0102 Oslo, Norway
HA Haga
Affiliation:
Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Pb 369 Sentrum, 0102 Oslo, Norway
*
∗ Contact for correspondence and requests for reprints: alex.mason@animalia.no
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Abstract

Head-to-body stunning is regarded as ‘best practice’ stunning for sheep. The benefits are loss of consciousness followed by cardiac arrest, death, prevention of animal movements post stun/kill and improved meat quality. Commercial equipment places electrodes on the head and back, which is known to cause pelt burning, thus reducing the value of the skins. The aim was to demonstrate that passing current at 1.5 A and 50 Hz from the top of the head to the chest in lambs for 3.1 s would result in epilepsy. Electroencephalographic (EEG) and electrocardiographic (ECG) activity was recorded in sheep using non-invasive electrodes. Measurements in this trial were successfully performed on three lambs (live weight 25 to 39 kg) which were anaesthetised and given neuromuscular blockers to inhibit muscle activity. EEG information showed that the head-to-chest stunning produced an epileptic-like episode, which was followed by an isoelectric output. ECG recordings showed that ventricular fibrillation (VF) was induced and coincided with the epileptic brain activity observed. No animals regained brain activity or sinus heart rhythm after applying the stated stunning conditions. As a conclusion, it is postulated that modified stunning equipment passing an electrical current from the top of the head to the sternum in lambs (1.5 A, 50 Hz; 3.1 s) may induce an epileptic seizure and VF.

Keywords

animal welfareEEGelectrical stunninghead-to-backhead-to-chestsheep
Type
Articles
Information
Animal Welfare , Volume 27 , Issue 4 , November 2018 , pp. 343 - 350
Copyright
© 2018 Universities Federation for Animal Welfare

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References

Anil, MH and McKinstry, JL 1992 The effectiveness of high fre-quency electrical stunning in pigs. Meat Science 31: 481–491. https://doi.org/10.1016/0309-1740(92)90030-8CrossRefGoogle Scholar
Ball, T, Kern, M, Mutschler, I, Aertsen, A and Schulze-Bonhage, A 2009 Signal quality of simultaneously recorded inva-sive and non-invasive EEG. Neuroimage 46: 708–716. https://doi.org/10.1016/j.neuroimage.2009.02.028Google ScholarPubMed
Blackmore, DK 1989 Electrocardiograms as an aid in assessing the stunning of cattle and pigs. New Zealand Veterinary Journal 37:59–61. https://doi.org/10.1080/00480169.1989.35560CrossRefGoogle ScholarPubMed
Blackmore, DK and Newhook, JC 1982 Electroencephalographic studies of stunning and slaughter of sheep and calves, Part 3: The duration of insensibility induced by electrical stunning in sheep and calves. Meat Science 7: 19–28. https://doi.org/10.1016/0309-1740(82)90094-8Google ScholarPubMed
Blackmore, DK and Petersen, GV 1981 Stunning and slaugh-ter of sheep and calves in New Zealand. New Zealand Veterinary Journal 29: 99–102. https://doi.org/10.1080/00480169.1981.34812Google ScholarPubMed
Cook, CJ, Devine, CE, Gilbert, KV, Smith, DD and Maasland, SA 1995 The effect of electrical head-only stun duration on elec-troencephalographic-measured seizure and brain amino acid neu-rotransmitter release. Meat Science 40: 137–147. https://doi.org/10.1016/0309-1740(94)00043-7CrossRefGoogle ScholarPubMed
Devine, CE, Gilbert, KV, Graafhuis, AE, Tavener, A, Reed, H and Leigh, P 1986 The effect of electrical stunning and slaughter on the electroencephalogram of sheep and calves. Meat Science 17: 267–281. https://doi.org/10.1016/0309-1740(86)90045-8CrossRefGoogle ScholarPubMed
European Union 2009 Council Regulation (EC) No 1099/2009 on the protection of animals at the time of killing. EC: Brussels, UKGoogle Scholar
Gilbert, KV, Devine, CE, Hand, R and Ellery, S 1984 Electrical stunning and stillness of lambs. Meat Science 11: 45–58. https://doi.org/10.1016/0309-1740(84)90016-0CrossRefGoogle ScholarPubMed
Gregory, NG 1998 Animal Welfare and Meat Science. CAB International: Wallingford, UKGoogle Scholar
Gregory, NG and Wotton, SB 1984 Observations on the mode of action of electrical stunning. Veterinary Anaesthesia and Analgesia 12:12–25. https://doi.org/10.1111/j.1467-2995.1984.tb00407.xGoogle Scholar
Haluk Anil, M 2012 Effects of slaughter method on carcass and meat characteristics in the meat of cattle and sheep. Final Project Report. EBLEX: UK. http://www.eblex.org.uk/wp/wp-content/uploads/2013/04/slaugh-ter_and_meat_quality_feb_2012-final-report.pdfGoogle Scholar
Llonch, P, Rodríguez, P, Casal, N, Carreras, R, Muñoz, I, Dalmau, A and Velarde, A 2015 Electrical stunning effective-ness with current levels lower than 1 A in lambs and kid goats. Research in Veterinary Science 98: 154–161. https://doi.org/10.1016/j.rvsc.2014.12.009CrossRefGoogle Scholar
Mason, A, Tolo, E and Haga, HA 2017 Non-invasive EEG meas-urement during electrical stunning of sheep. In: Mukhopdhyay, S (ed) International Conference on Sensing Technology pp 162–167. 4-6 December 2017, IEEE, Sydney, AustraliaGoogle Scholar
Sánchez-Barrera, IC, Albarracin, W and Rojas, MJ 2014 Electroencephalographic spectrum power of sheep's brain after stunning. Journal of Applied Animal Research 42: 73–76. https://doi.org/10.1080/09712119.2013.822805CrossRefGoogle Scholar
Tatum, WO 2014 Normal EEG. In: Tatum, WO (ed) Handbook of EEG Interpretation pp 376. Demos Medical Publishing: New York, USA. https://doi.org/10.1891/9781617051807.0001CrossRefGoogle Scholar
Verhoeven, MTW, Gerritzen, MA, Kluivers-Poodt, M, Hellebrekers, LJ and Kemp, B 2015 Validation of behavioural indicators used to assess unconsciousness in sheep. Research in Veterinary Science 101: 144–153. https://doi.org/10.1016/j.rvsc.2015.06.007CrossRefGoogle ScholarPubMed