Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-23T15:22:24.969Z Has data issue: false hasContentIssue false
  • English
  • Français

Assessing pig welfare at stunning in Swedish commercial abattoirs using CO2 group-stun methods

Published online by Cambridge University Press:  01 January 2023

S Atkinson ,
A Velarde ,
P Llonch  and
B Algers
S Atkinson*
Affiliation:
Department of Animal Environment and Health, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Box 234, 532 23 Skara, Sweden
A Velarde
Affiliation:
Animal Welfare Subprogram, IRTA, Finca Camps i Armet s/n Monells, 17121, Girona, Spain
P Llonch
Affiliation:
Animal Welfare Subprogram, IRTA, Finca Camps i Armet s/n Monells, 17121, Girona, Spain
B Algers
Affiliation:
Department of Animal Environment and Health, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Box 234, 532 23 Skara, Sweden
*
* Contact for correspondence and requests for reprints: Sophie.Atkinson@slu.se
Get access Rights & Permissions [Opens in a new window]

Abstract

While regular monitoring of stun quality in abattoirs is now required by EU law, guidelines specific to species and stun method have not been adequately developed. Carbon dioxide (CO2) gas stunning of pigs in groups is widely used because of efficiency and reduced pre-slaughter stress. However, some pigs may recover from the stun process if it is not correctly managed. In light of these concerns, this study aimed to develop and implement a standardised assessment for stun quality for use in commercial pig abattoirs. Eight abattoirs and 9,520 slaughter pigs were assessed for stun group size, stick time and stun quality. The stun system, CO2 concentrations and exposure times were also investigated. A stun-quality protocol (SQP) identified and risk-rated symptoms signifying recovery of consciousness. In abattoirs using paternoster stun-boxes, pigs consistently showed no stun-quality problems despite 65% with stick times between 70 and 100 s. Stun-quality problems were detected in 1.7 to 3.3% of pigs in abattoirs using dip-lift stun-boxes and 75% of stick times were below 60 s. In 36 of 38 cases of inadequately stunned pigs, a combination of symptoms from the SQP was seen. Regular gasping preceded other symptoms in 31 cases and was a valid indicator of inadequate stunning. In response to the stun-quality assessments, two abattoirs serviced the stun machines (increasing CO2 concentrations and exposure times). All pigs were adequately stunned in follow-up studies. Implementation of stun-quality assessments, such as developed in this study, can assure monitoring of animal welfare at slaughter, beneficial not only to the industry and relevant authorities but also the concerned consumer.

Keywords

animal welfareCO2 stunningcommercial abattoirspig welfarestun-quality assessmentstun-quality protocol
Type
Research Article
Information
Animal Welfare , Volume 21 , Issue 4 , November 2012 , pp. 487 - 495
Copyright
© 2012 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, A and McKinstry, J 1991 Reflexes and loss of sensibility following head to back electrical stunning in sheep. The Veterinary Record 128(5): 106–107. http://dx.doi.org/10.1136/vr.128.5.106CrossRefGoogle ScholarPubMed
Anil, A and McKinstry, J 1993 Results of a survey of pig abattoirs in England and Wales. MAFF Meat Hygiene Division: Tolworth, London, UKGoogle Scholar
Anil, A, Whittington, P and McKinstry, J 2000 The effect of the sticking method on the welfare of slaughter pigs. Meat Science 55: 315–319CrossRefGoogle ScholarPubMed
Anil, MH 1991 Studies on the return of physical reflexes in pigs following electrical stunning. Meat Science 30: 13–21. http://dx.doi.org/10.1016/0309-1740(91)90030-TCrossRefGoogle ScholarPubMed
Barton-Gade, P and Christensen, L 2002 Transportation and pre-stun handling: CO2-systems. Veterinary Congress pp 1–5. 19-27 November 2002, Helsinki, FinlandGoogle Scholar
Channon, HA, Payne, AM and Warner, R 2003 Effect of stun duration and current level applied during head to back and head only electrical stunning of pigs on pork quality compared with pigs stunned with CO2. Meat Science 65: 1325–1333. http://dx.doi.org/10.1016/S0309-1740(03)00053-6CrossRefGoogle ScholarPubMed
Christensen, L and Barton-Gade, P 1997 New Danish developments in pig handling at abattoirs. Fleischwirtschaft International 77: 604–607Google Scholar
Dalmau, A, Temple, D, Rodríguez, P, Llonch, P and Velarde, A 2009 Application of the Welfare Quality® protocol at pig slaughterhouses. Animal Welfare 18: 497–505Google Scholar
Danish Meat Research Institute 2011 http://www.dti.dk/specialists/30402?cms.query=guidlines+for+co2+stunningGoogle Scholar
EC (European Community) 1993 Council Directive No 93/119/EC on the protection of animals at the time of slaughter or killing. EC: Brussels, BelgiumGoogle Scholar
EC (European Community) 2009 Council Regulation No 1099/2009 on the protection of animals at the time of killing. Official Journal of the European Union L303: 1-30. EC: Brussels, BelgiumGoogle Scholar
EFSA 2004 Welfare aspects of animal stunning and killing methods. Scientific Report on the Scientific Panel for Animal Health and Welfare on a request from the Commission. Adopted on the 15th of June 2004. EFSA: Brussels, BelgiumGoogle Scholar
Forslid, A 1987 Transient neocortical, hippocampal and amygdaloid EEG silence induced by one-minute inhalation of high concentration carbon dioxide in swine. Acta Physiological Scandinavica 130: 1–10CrossRefGoogle ScholarPubMed
Grandin, T 2010 Recommended animal handling guidelines and audit guide. A systematic approach to animal welfare. American Industry Foundation: USAGoogle Scholar
Gregory, N 1999 Animal Welfare and Meat Science. CABI Publishing: Oxford, UKGoogle Scholar
Gregory, N, Moss, BW and Leeson, RH 1987 An assessment of carbon dioxide stunning in pigs. Veterinary Record 121: 517–518. http://dx.doi.org/10.1136/vr.121.22.517CrossRefGoogle ScholarPubMed
Hall, LW, Clarke, KW and Trim, CM 2001 Veterinary Anaesthesia, Tenth Edition. Harcourt Publishers: UKGoogle Scholar
Hartmann, H, Rindermann, G, Siegling-Vlitakis, C, Arndt, G, Wolf, K and Fries, R 2010 Relationship between the response to the corneal reflex (depth of narcosis) and specific parameters in the slaughter blood of pigs narcotised with CO2. Animal Welfare 19: 515–522Google Scholar
Holleben, KV, Schuette, A, Wenzlawowicz, MV and Bostelmann, V 2002 Call for veterinary action in the slaughterhouses. Deficient welfare at CO2 stunning of pigs and captive bolt stunning of cattle. Fleischwirtschaft International 3: 8–10Google Scholar
Holst, S 2001 Carbon dioxide stunning of pigs for slaughter. Practical Guidelines for Science and Technology, Good Animal Welfare. Proceedings of the 47th International Congress of Meat Science pp 48–54. 21-26 August 2001, Krakow, PolandGoogle Scholar
Nowak, B, Mueffling, TV and Hartung, J 2007 Effect of different carbon dioxide concentrations and exposure time in stunning of slaughter pigs: Impact on animal welfare and meat quality. Meat Science 75: 290–298. http://dx.doi.org/10.1016/j.meatsci. 2006.07.014CrossRefGoogle ScholarPubMed
Official Statistics Sweden 2011 07JO 48SM 1109. http://www.scb.se/Pages/PublishingCalendarViewInfo259923.aspx?PublObjId=15811Google Scholar
Panella-Riera, N, Dalmau, A, Fabrega, E, Font, I, Furnols, M, Gispert, M, Tibau, J, Soler, J, Velarde, A, Oliver, MA and Gil, M 2008 Effect of supplementation with MgCO3 and L-Tryptophan on the welfare and on the carcass and meat quality of two halothane pig genotypes (NN and nn). Livestock Science 115: 107–117. http://dx.doi.org/10.1016/j.livsci.2007.06.014CrossRefGoogle Scholar
Raj, M 1999 Behaviour of pigs exposed to mixtures of gases and the time required to stun and kill them: welfare implications. The Veterinary Record 13: 165–168. http://dx.doi.org/10.1136/vr.144.7.165CrossRefGoogle Scholar
Rodríguez, P, Dalmau, A, Ruiz-de-la-Torre, JL, Manteca, X, Jensen, EW, Rodríguez, B, Litvan, H and Velarde, A 2008 Assessment of unconsciousness during carbon dioxide stunning in pigs. Animal Welfare 17: 341–349Google Scholar
SJVFS 2008 69: L22: Chapter 7:2. Swedish Board of Agriculture: Jönköping, SwedenGoogle Scholar
Stoier, S, Aaslyng, MD, Olsen, EV and Henckel, P 2000 The effect of stress during lairage and stunning on muscle metabolism and drip loss in Danish pork. Meat Science 59: 127–131. http://dx.doi.org/10.1016/S0309-1740(01)00040-7CrossRefGoogle Scholar
Terlouw, EMC, Arnould, C, Auperin, B, Berri, C, Le Bihan-Duval, E, Deiss, V, Lefe, F, Lensink, BJ and Mounier, L 2008 Pre-slaughter conditions, animal stress and welfare: current status and possible future research. Animal 2: 1501–1517. http://dx.doi.org/10.1017/S1751731108002723CrossRefGoogle ScholarPubMed
Tranquilli, WJ and Thurmon, JC 2007 Veterinary Anaesthesia and Analgesia. Blackwell Publishing: Iowa, USAGoogle Scholar
Van de Perre, V, Permentier, L, De Bie, S, Verbeke, G and Geers, R 2010 Effect of unloading, lairage, pig handling, stunning and season on pH of pork. Meat Science 86: 931–937. http://dx.doi.org/10.1016/j.meatsci.2010.07.019CrossRefGoogle ScholarPubMed
Velarde, A, Gispert, M, Faucitano, L, Manteca, X and Diestre, A 2000a Effect of stunning method on the incidence of PSE meat and haemorrhages in pork carcasses. Meat Science 55: 309–314. http://dx.doi.org/10.1016/S0309-1740(99)00158-8CrossRefGoogle ScholarPubMed
Velarde, A, Gispert, L, Faucitano, L and Diestre, A 2000b Survey of the effectiveness of stunning procedures used in Spanish pig abattoirs. Veterinary Record 146: 65–68. http://dx.doi.org/10.1136/vr.146.3.65CrossRefGoogle ScholarPubMed
Velarde, A, Ruiz-de-la-Torre, J, Roselló, C, Fabrega, E, Diestre, A and Manteca, X 2002 Assessment of return to consciousness after electrical stunning in lambs. Animal Welfare 11: 333–341Google Scholar
Vogel, KD, Badtram, G, Claus, IR, Grandin, T, Turpin, S, Weyker, RE and Voogd, E 2011 Head-only followed by cardiac arrest electrical stunning is an effective alternative to head-only electrical stunning in pigs. Journal of Animal Science 89: 1412–1418CrossRefGoogle ScholarPubMed
Von Holleben, K, von Wenzlawowic, M, Gregory, N, Anil, H, Velarde, A, Rodríguez, P, Cenci Goga, B, Catanese, B and Lambooij, B 2010 Report on good and adverse practices: Animal welfare concerns in relation to slaughter practices from the viewpoint of veterinary sciences. Dialrel report. http://www.dialrel.eu/images/veterinary-concerns.pdfGoogle Scholar