Characterizing candidate decompression rates for hypobaric hypoxic stunning of pigs. Part 1: Reflexive behavior and physiological responses.

Autor: Martin JE; The Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom.; School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom., Baxter EM; Animal and Veterinary Sciences Research Group, Scotland's Rural College (SRUC), Edinburgh, United Kingdom., Clarkson JM; School of Biodiversity, One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom., Farish M; Animal and Veterinary Sciences Research Group, Scotland's Rural College (SRUC), Edinburgh, United Kingdom., Clutton RE; The Wellcome Trust Critical Care Laboratory for Large Animals LARIF, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom., Greenhalgh SN; The Wellcome Trust Critical Care Laboratory for Large Animals LARIF, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom., Gregson R; The Wellcome Trust Critical Care Laboratory for Large Animals LARIF, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom., McKeegan DEF; School of Biodiversity, One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
Jazyk: angličtina
Zdroj: Frontiers in veterinary science [Front Vet Sci] 2022 Nov 29; Vol. 9, pp. 1027878. Date of Electronic Publication: 2022 Nov 29 (Print Publication: 2022).
DOI: 10.3389/fvets.2022.1027878
Abstrakt: Alternatives to carbon dioxide (CO 2 ) stunning for the commercial slaughter of pigs are urgently needed because there is robust evidence that exposing pigs to hypercapnic environments is associated with pain, fear, and distress. Hypobaric hypoxia (via gradual decompression, also known as Low Atmospheric Pressure Stunning or LAPS) has been validated in poultry as a humane option, but its potential to improve the welfare of pigs at slaughter is unknown. We investigated the potential of hypobaric hypoxia to reliably elicit a non-recovery state in anesthetized weaner-grower pigs within a commercially viable timeframe. We determined the effect of candidate decompression rates (40, 60, 80, 100 ms -1 , at two cycle durations 480 s and 720 s) on a range of physiological and reflexive behavioral indicators of hypoxia and death. We found that the decompression rates tested caused a 100% death rate. As expected, the decompression rate had overarching effects on behavioral and physiological markers of hypoxia and death, with faster decompression rates resulting in shorter latencies to cardiac arrest and cessation of breathing. We observed a higher proportion of pigs displaying repeated and prolonged whole-body movements (likely indicative of convulsive activity) at higher frequencies when we applied the slowest decompression rate (40 ms -1 ) compared to all other rates. Since these responses may impact the carcass and meat quality, the slower rate of decompression (40 ms -1 ) should be excluded as a candidate decompression rate. Furthermore, given the marginal effects of decompression rate on physiological indicators of death and reflexive behavioral parameters, we also recommend that the fastest rate tested (100 ms -1 ) is excluded in further study on conscious pigs (to prevent conscious animals from being exposed to unnecessary faster decompression rates which may compromise animal welfare). This work represents a necessary proof of principle step and confirms the potential of gradual decompression for stunning purposes in pigs. Importantly, however, the data presented provide no information on the welfare outcomes associated with decompression in conscious pigs. Subsequent work should focus on the comprehensive welfare assessment of intermediate decompression rates to determine the potential of hypobaric hypoxia to provide a humane stunning method for pigs.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Martin, Baxter, Clarkson, Farish, Clutton, Greenhalgh, Gregson and McKeegan.)
Databáze: MEDLINE
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