Emergency depopulation of chicken farms during an avian influenza outbreak (design and development of whole house gassing and sealing method for offsite testing facility)

Abstract

The method of whole house gassing using carbon dioxide gas has been used extensively overseas in countries like Canada and Netherlands for depopulating spent-hens and preventing the outbreak of Avian Influenza in both barn and multi-tiered cage environments for chickens. Carbon dioxide gas is favoured and deemed humane for culling as it displaces oxygen and does not suffocate the chickens but rather provides an anaesthesia effect. This causes the chickens to feel a loss of sensation and awareness to pain which eventually lead to death after higher concentrations of carbon dioxide is introduced. However, such methodologies have not yet been tested and proven in Singapore. In collaboration with the Agri-Food Veterinary Authority of Singapore, the aim of this research is to pilot the feasibility and the outcome of whole house gassing using Carbon Dioxide Gas in Singapore while taking into consideration the welfare of the chickens through experimental Offsite Testing Facility. Design and development of the mock-up for the adopted whole house gassing method and sealing of the experiment will be discussed in this report, along with the experimental outcomes to validate the designs. This report is in conjunction with the design and development of the delivery and measurement system that are discussed by Chang Wei Jun Zachary and Wong Teng How Adam respectively.