A Systematic Literature Review on Depopulation Methods for Swine

Area of Science:

• Veterinary Science
• Animal Welfare Science
• Agricultural Science

Background:

• Swine mass depopulation addresses welfare issues from slaughter delays, exemplified by the 2020 COVID-19 pandemic.
• This practice involves the destruction of large numbers of pigs, potentially including healthy animals.

Purpose of the Study:

• To systematically review existing literature on swine depopulation methods.
• To identify critical knowledge gaps in current depopulation practices and research.

Main Methods:

• A systematic literature search was conducted across major electronic databases (Web of Science, MEDLINE, PubMed).
• Sixty-eight peer-reviewed publications on swine depopulation were assessed.

Main Results:

• Carbon dioxide inhalation was the most frequently reported method for both small and large-scale depopulation.
• A significant proportion of studies lacked measurements of consciousness to assess animal suffering and humaneness.
• No published method reliably and safely induces rapid unconsciousness in large groups of pigs.

Conclusions:

• There is a critical need for developing rapid, reliable, and safe mass depopulation methods for large swine groups.
• Standardized reporting guidelines for depopulation studies are urgently required to ensure consistent evaluation of animal welfare.
• Improved methods are necessary for emergency preparedness, balancing cost, personnel safety, and animal welfare standards.