A Systematic Literature Review on Depopulation Methods for Swine
Abstract
:Simple Summary
Abstract
1. Introduction
2. Materials and Methods
2.1. Article Search Strategy
2.2. Article Screening and Selection Criteria
- Type of study: descriptive and analytical (observational and experimental) studies
- Date of publication: articles published between January 1990 and May 2020
- Geographic focus: worldwide
- Population: applied to individual pigs or groups
- Outcomes/efficiency measurements: speed of unconsciousness, insensibility, and death
2.3. Article Assessment Process
3. Results
3.1. Overview of the Included Studies
3.2. Small-Scale Studies Using AVMA Preferred Depopulation Methods
3.2.1. Injectable Anesthetic Agents
3.2.2. Inhaled Agents/Gas
3.2.3. Physical Methods
3.3. Small-Scale Studies Using Methods Permitted in Constrained Circumstances
3.3.1. Ingested/Oral Formulations
3.3.2. Other: Ventilation Shutdown
3.4. Depopulation Methods Scalable to Large Populations
3.5. Important Considerations for Depopulation Studies
4. Discussion
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Age Category | Method | Preferred | Permitted in Constrained Circumstances |
---|---|---|---|
All ages | Injectable | Anesthetic overdose, intravenous barbiturates and barbituric acid derivatives | Expired, compounded, non-pharmaceutical grade injectable euthanasia agents or anesthetics |
Inhaled/gas | Carbon dioxide | ||
Physical methods | Gunshot to the head (not appropriate for depopulation of suckling pigs), penetrating captive bolt, electrocution | ||
Ingested/Oral | Sodium nitrate | ||
Other | Ventilation shutdown (VSD) or VSD plus | ||
Only for suckling and young pigs | Physical methods | Manual blunt force trauma, non-penetrating captive bolt |
National Pork Board (NPB), 2016 [47] | OIE, 2019 [53] | ||||||
---|---|---|---|---|---|---|---|
Human Safety Risk | Skill Required | Aesthetics | Limitations | Approved for | Restraint Necessary | Animal Welfare Concerns If Applied Inappropriately | |
Carbon dioxide (CO2) | moderate | moderate to low, based on equipment design | bloodless, some excitatory movement or vocalization | practical for small pigs only; maintenance of equipment | all ages (may not be practical for pigs over 70 pounds (31.7 kg)) | yes | slow induction of unconsciousness, averseness of induction |
Gunshot | high | moderate to high | discharge of blood from wound | security of firearms; legal restrictions; maintenance of equipment | nursery pigs or older | no | non-lethal wounding |
Non-penetrating captive bolt | low | low | minimal to some blood discharge as a 1-step process | may be a 2-step process based on equipment design and size of pig; maintenance of equipment | pigs less than 70 pounds (31.7 kg) | yes | non-lethal wounding |
Penetrating captive bolt | moderate | moderate | discharge of blood from wound | may be a 2-step process depending on equipment design; maintenance of equipment | pigs greater than 12 pounds (5.4 kg) | yes | ineffective stunning, non-lethal wounding, regaining of consciousness before death |
Electrocution (head-only and head-to-heart) | low if proper lock out/tag out procedure followed | moderate | muscle contraction; minimal to no blood discharge | adequate amperage and voltage needed; head only is a 2-step process; cleanliness of electrodes | pigs over 3 days of age | yes | pain associated with cardiac arrest after ineffective stunning; design of the stunning tongs not appropriate for the small head or body of neonates |
Veterinarian administered anesthetic overdose | low | high, veterinary administration only | no blood discharge, limited pig movements | applicable agents available only to licensed veterinarian; carcass disposal | all ages but may not be practical | yes | non-lethal dose, pain associated with injection site |
Manual blunt force trauma | low | moderate | some blood discharge; objectionable for some | only applicable to small pigs; ability of caretaker to apply sufficient force | pigs up to 12 pounds (5.4 kg) | yes | non-lethal wounding |
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Arruda, A.G.; Beyene, T.J.; Kieffer, J.; Lorbach, J.N.; Moeller, S.; Bowman, A.S. A Systematic Literature Review on Depopulation Methods for Swine. Animals 2020, 10, 2161. https://doi.org/10.3390/ani10112161
Arruda AG, Beyene TJ, Kieffer J, Lorbach JN, Moeller S, Bowman AS. A Systematic Literature Review on Depopulation Methods for Swine. Animals. 2020; 10(11):2161. https://doi.org/10.3390/ani10112161
Chicago/Turabian StyleArruda, Andréia G., Tariku J. Beyene, Justin Kieffer, Joshua N. Lorbach, Steven Moeller, and Andrew S. Bowman. 2020. "A Systematic Literature Review on Depopulation Methods for Swine" Animals 10, no. 11: 2161. https://doi.org/10.3390/ani10112161