Location: Poultry Microbiological Safety and Processing Research UnitTitle: Broiler chicken euthanasia by cervical dislocation: manual versus mechanical methods
|JACOBS, LEONIE - Virginia Tech|
|BOURASSA, DIANNA - Auburn University|
|Buhr, Richard - Jeff|
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/19/2018
Publication Date: 1/22/2019
Citation: Jacobs, L., Bourassa, D.V., Harris, C.E., Buhr, R.J. 2019. Broiler chicken euthanasia by cervical dislocation: manual versus mechanical methods [abstract]. International Poultry Scientific Forum. 98(E-Suppl.1):M121. p.38.
Technical Abstract: Manual cervical dislocation (MCD) is a common method to euthanize broiler chickens, but can be challenging due to fatigue or a lack of strength or training. Mechanical cervical dislocation is a potential alternative. The aim was to assess the onset of brain stem death based on the birds’ loss of induced reflex responses and skeletal muscle movements for two euthanasia methods. On three experimental days broilers were euthanized at 36 (n=60), 42 (n=80), and 43 days old (n=60), by MCD or the Koechner Euthanizing Device (KED). On the first day euthanasia was applied prior to bird placement in a cone. On days 2 and 3, euthanasia was applied to birds in cones and a modified KED treatment was added with the application of the KED, plus a head extension ~90 degrees (KED+). On those 2 days, gap size was estimated between the atlas cervical vertebra and the skull (cm). The onset of brain death was assessed by recording the cessation of the nictitating eye membrane reflex, gasping reflex and skeletal muscle movements (sec). Additionally, neck skin damage was recorded (y/n). In each batch (P<0.05 for all main effects, with exception of cessation of movement in batch 2, with P=0.073), MCD resulted in quicker loss of reflexes and movements (batch means of eye reflex duration: 2, 17, 19 sec; gasp duration: 0, 3, 20 sec; movement duration: 73, 88, 154 sec) compared to KED (batch means of eye reflex duration: 44, 58, 101 sec; gasp duration: 46, 64, 119 sec; movement duration: 89, 106, 193 sec), or KED+ (batch means of eye reflex duration: 46, 50 sec; gasp duration: 46, 56 sec; movement duration: 92, 110 sec). The eye reflex was absent and returned in 0, 10, and 15% of MCD birds, in contrast to 50 and 55% of KED birds (no data from batch 1), and 40 and 60% of KED+ birds. Skin damage occurred in 0% of MCD birds, 68, 75, and 95% of KED birds, and 85 and 95% of KED+ birds. In batch 2 and 3 KED birds had or tended to have a narrower skull-to-atlas gap compared to MCD and KED+ birds (P=0.008, P=0.065). In all three batches, MCD resulted in quicker death in broilers of 36, 42 and 43 days old. Although the additional head extension in KED+ resulted in similar skull-to-atlas gap as MCD, reflexes and movements persisted. Therefore, MCD would be the recommended euthanasia method for broilers.