Browsing by Author "Wahltinez SJ"

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    Evaluation of insensibility in humane slaughter of teleost fish including the use of electroencephalogram with a case study on farmed barramundi (Lates calcarifer)
    (Elsevier B V, 2024-09-15) Wahltinez SJ; Cohen S; Hardy-Smith P; Huynh C; Kells N
    Humane slaughter methods for fish are an important facet of responsible farming practice that can both minimise animal distress and improve product quality. In addition, consumers are increasingly demanding good welfare across all phases of farmed animal production, including at slaughter. As a result, many intergovernmental organisations, government bodies, and third-party certification schemes now include fish slaughter practices in their legislation, guidelines, and audit schemes. In order to be considered humane, slaughter methods should not be aversive to the fish and should result in rapid insensibility without recovery of consciousness prior to death. Where the act of slaughter does not cause immediate loss of sensibility, this should be preceded by an effective stunning method that induces rapid insensibility that is maintained until death. However, determining when fish are insensible is challenging. The effective evaluation of insensibility and stunning is important to prevent any suffering or distress that might occur when invasive killing methods, such as bleeding or evisceration, are used. Insensibility may be assessed using observable indicators such as fish behaviour, or objectively through measuring brain activity using electroencephalography. There is concern that observable indicators, such as opercular movement, righting responses, and spontaneous movement, may not be reliable signs of insensibility. It is therefore important to validate these observable indicators using objective measures, which can determine when electrical changes in the brain occur that indicate insensibility. Barramundi (Lates calcarifer) are an important aquaculture species that are farmed worldwide. Currently, this species is usually slaughtered by ice slurry immersion, a practice which has raised welfare concerns in other fish species. The objectives of this review are to provide background on current slaughter methods used for teleost fish, to summarise the methods used to evaluate insensibility in fish at stunning and slaughter, and to describe the current practices and future directions for the slaughter of farmed barramundi.