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Further study to develop a humane method to kill poultry using gas filled foam - MH0144

DEFRA and Animal Health as their operational partner, have a requirement for in-situ emergency killing of poultry flocks in the event of a notifiable disease outbreak. Two systems are currently available for use, the Containerised Gassing Units (CGU) and Whole House Gassing (WHG). Not all poultry buildings are suitable for WHG due to the fact they cannot be adequately sealed, in particular mobile free range poultry houses which may have colonies of up to 4000 birds. According to the GB Poultry Register as at 7 March 2007, there were 23,982 premises in Great Britain of this size, and a total of 13,049 premises (54%) are registered as having possible outdoor access. DEFRA has previously funded a study to assess the efficacy of low density foam as a humane method of anoxic gas delivery for whole house killing of poultry (MH0143). This work investigated the effect of nitrogen filled foam on individual birds and showed that the method was highly effective and humane. There is some concern about the efficacy of foam when applied to groups of birds, and more work is needed to determine critical parameters affecting efficacy such as depth of foam and optimum stocking density. This will allow an operational protocol to be developed.

A small number of trials have been made on groups of poultry both in the UK and in Holland which have indicated that wing flapping of groups of poultry can cause significant destruction of the foam and that the height of foam above birds before flapping onset (15 – 18 s after submersion) is critical. Other field trials have shown that rather than the gross volume flow rate of the foam, it is the forward speed and the depth and distribution of the foam bow wave that will have the most significant impact on the effectiveness of the technique. Further research is required to refine this approach and make its practical application in disease control situations a possibility.
Objective 1. Using different forward speeds and depths of foam bow wave, determine the depth of foam required at the point the birds start flapping, how much foam is destroyed and how this is affected by stocking density.

Objective 2. Determine how the factors in objective 1 impact on the likelihood of birds regaining consciousness (measured by EEG), allowing clear recommendations about foam delivery to be made.

Objective 3. Develop a field method to evaluate the quality and suitability of a sample of foam to kill birds quickly, safely and reliably.

Objective 4. Contribute to practical recommendations for design including an operational protocol.
Project Documents
• EVID4 - Final project report : MH0144 Final report   (734k)
Time-Scale and Cost
From: 2009

To: 2010

Cost: £75,049
Contractor / Funded Organisations
University - Glasgow, Livetec
Animal Welfare              
Plants and Animals              
Fields of Study
Animal Welfare