Comparison of Water-Based Foam and Inert-Gas Mass Emergency Depopulation Methods

Abstract

Current control strategies for avian influenza (AI) and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. Selection of the best method of emergency mass depopulation involves maximizing human health and safety while minimizing disease spread and animal welfare concerns. Proper selection must ensure that the method is compatible with the species, age, housing type, and disposal options. No one single method is appropriate for all situations. Gassing is one of the accepted methods for euthanatizing poultry. Whole-house, partial-house, or containerized gassing procedures are currently used. The use of water-based foam was developed for emergency mass depopulation and was conditionally approved by the United States Department of Agriculture in 2006. Research has been done comparing these different methods; parameters such as time to brain death, consistency of time to brain death, and pretreatment and posttreatment corticosterone stress levels were considered. In Europe, the use of foam with carbon dioxide is preferred over conventional water-based foam. A recent experiment comparing CO2 gas, foam with CO2 gas, and foam without CO2 gas depopulation methods was conducted with the use of electroencephalometry results. Foam was as consistent as CO2 gassing and more consistent than argon-CO2 gassing. There were no statistically significant differences between foam methods.

Technical assistance to the Commission (Article 31 of Regulation (EC) No 178/2002) for the preparation of a data collection system of welfare indicators in EU broilers’ slaughterhouses

“…The method used for culling impacts animal welfare (van den Berg and Houdart, 2008;Alphin et al, 2010).…”

Comparison of water-based foam and carbon dioxide gas mass emergency depopulation of White Pekin ducks

“…Two leads were implanted in the complexus muscle just below the base of the skull for electromyography (EMG). The ducks were given 0.4 mg/kg of carprofen injection subcutaneously after the procedure and were then allowed to recover for 24 h. The surgical procedure was based on Kostal (1997, 2006) and Alphin et al (2010).…”

“…Previous studies compared the effectiveness of CO 2 gassing Alphin et al, 2010) and argon-carbon dioxide gassing (Alphin et al, 2010) to water-based foam for the depopulation of floor-reared poultry and found that the mentioned methods are comparable. There are physiological differences in the mechanisms causing death for foam and CO 2 gas.…”

Application of wireless electroencephalogram (EEG) to measure stress in ducks

“…EEG has been used to monitor brain activity of humans and a number of different species. EEG has been used in connection with animal welfare studies to determine the time to unconsciousness and brain death during euthanasia or depopulation (Alphin et al, 2010;Gerritzen et al, 2006;Raj, 1998). Radiotelemetery systems have been used to allow the real time measurement of heart rate, blood pressure, body temperature and telencephalic EEG to be used as an indicator of bird welfare parameters (Savory and Kostal, 1997).…”

“…The hypothesis of these two experiments was that an increase would be seen in the relative alpha or relative beta frequencies and a decrease would be seen in the relative delta or relative theta frequencies during the application of stressful stimuli. It was assumed that relative delta/theta would decrease during a stressful period because relative delta/theta tend to increase during unconsciousness , when an animal is not responding to stimuli (Lambooij et al, 2002;Lopes, 1983;Raj et al, 1992;Raj, 1998, Gerritzen et al, 2004Alphin et al, 2010). Plasma corticosterone levels were used in Experiment 2 as a standard measure of evaluating stress (Harvey et al, 1980;Klingbeil, 1985;de Boer et al, 1988) against which any changes seen in the relative frequency bands of the EEG were measured.…”