Rapid loss of consciousness in cattle following nonstun slaughter: evidence from a systematic review.

Résumé

BACKGROUND: Accepting that it is ethical for meat to be consumed as food, then, in any context, religious or secular, it is indefensible for animals to be subjected to undue pain. Animal slaughter must therefore be predicated on the minimization of pain. Nonstun slaughter (NSS) of bovines involves ventral neck incisions, resulting in an abrupt loss of cortical blood flow and causing nearly instantaneous loss of consciousness (LOC). However, some reports have suggested that LOC after NSS is not instantaneous. This paper presents an overview of the neurobiology underlying NSS and a systematic review of the literature on time to LOC in bovines following NSS.METHODS: A literature review was conducted across PubMed, Google Scholar, the Cochrane Library, Medline, and the Web of Science, with 3 coauthors independently screening articles to reduce bias. Only original research and review articles specifically addressing time to LOC in bovines after NSS were included; studies not focused on this outcome were excluded. The quality of evidence was ranked based on hierarchy of evidence utilizing predefined criteria.RESULTS: 15 studies were identified: 4 high quality, 3 medium quality, and 8 low quality. High-quality evidence consistently indicates that LOC occurs within 10 seconds of NSS of bovines when done correctly with low-stress, ideal slaughterhouse conditions.CLINICAL RELEVANCE: Our findings provide important insights to optimize NSS practices, promoting animal welfare while maintaining religious requirements.