Welfare assessment of novel on-farm killing methods for poultry

PLoS One. 2019 Feb 22;14(2):e0212872. doi: 10.1371/journal.pone.0212872. eCollection 2019.

Abstract

There is a need for novel mechanical devices for dispatching poultry on farm following the introduction of EU Regulation (EC) no. 1099/2009 On the Protection of Animals at the Time of Killing. We examined three novel mechanical killing devices: Modified Armadillo, Modified Rabbit Zinger, a novel mechanical cervical dislocation device; and traditional manual cervical dislocation. The four killing methods were tested on 230 chickens across four batches. We measured behavioural, electroencephalogram and post-mortem outcomes in anesthetized laying hens and broilers at two life stages (juveniles and adults/slaughter age). Graeco Latin-Square designs systematically randomized killing treatment, bird type, age and kill order. All birds were lightly anaesthetized immediately prior to the killing treatment with inhalation of Sevoflurane. The novel mechanical cervical dislocation method had the highest kill success rate (single application attempt only, with no signs of recovery) of a mechanical method (96%). The Modified Armadillo was the least reliable with 49% kill success. Spectral analysis of electroencephalogram signals at 2 s intervals for successfully killed birds only revealed progressive decreases in median frequency alongside increases in total power. Later, total power decreased as the birds exhibited isoelectric electroencephalogram signal. Latencies to pre-defined spectral ranges associated with unconsciousness showed that birds subjected to manual and novel mechanical cervical dislocation achieved these states sooner than birds subjected to the modified Armadillo. Nevertheless all methods exhibited short latencies (<4 s). The Modified Rabbit Zinger had the shortest duration of reflex persistence for nictitating membrane, pupillary and rhythmic breathing post method application. Of the methods tested, the novel mechanical cervical dislocation device is the most promising mechanical method for killing poultry on-farm based on a range of behavioural, electroencephalogram and anatomical parameters. This device has the potential to fulfil the current need for a mechanical alternative to manual cervical dislocation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Husbandry / methods*
  • Animal Welfare*
  • Animals
  • Behavior, Animal
  • Chickens
  • Electrodes
  • Electroencephalography
  • Female
  • Poultry
  • Rabbits
  • Turkeys

Associated data

  • figshare/10.6084/m9.figshare.7021691.v1

Grants and funding

This research was funded by the Humane Slaughter Association (HSA, https://www.hsa.org.uk/) via their Centenary Research Training Scholarship (RTS), awarded to JM in 2011. Livetec Systems Ltd. provided support in the form of salary to JS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.