Welfare indicators for stunning versus non-stunning slaughter in sheep and cattle: A scoping review

Abstract

Background: While most cattle and sheep in the United Kingdom are stunned before slaughter, non-stun methods are permitted to supply meat to specific consumers. This study aimed to identify the existing literature that compared animal welfare indicators during stun and non-stun slaughter, using a scoping review framework. Method: Following a structured search strategy, including the establishment of a PICO (population, intervention, comparator and outcomes) question, a comprehensive literature search of the CAB Abstracts, MEDLINE and PubMed databases, was conducted. A total of 962 papers were identified, of which 16 were selected for data extraction. Results: Fourteen papers concluded that welfare at slaughter was negatively impacted at non-stun slaughter in comparison to stun slaughter; two papers were inconclusive. Welfare indicators identified included biochemical parameters, brain activity and visual signs of consciousness. Limitations regarding inconsistent restraint method, neck cut position and non-standardised measures of welfare at slaughter are highlighted. Conclusions: This study provides further evidence that stunning is an effective method to improve the welfare of sheep and cattle at slaughter. Animal welfare advisors, politicians, religious communities and others interested in animal welfare could use the findings to further discuss and establish new dialogues for producing updated guidance on animal welfare at slaughter.