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Fish welfare quality as affected by pre-slaughter and slaughter management

Springer Nature
Aquaculture International
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. A reliable assessment of animal welfare-suffering and of its impact on product quality requires a multidisciplinary approach that takes into account fish behaviour and the different biochemical and physiological processes involved. This might be done by the contemporary study of changes of indicators of brain function, endocrine responses, post mortem tissue biochemical processes and quality changes. This work reviewed some of the most used indices of stress at the time of slaughter, commercial slaughter methods and related stress effects on physical and biochemical parameters of fish quality. The set of the available data seemed to indicate that, although of some results appear contradictory, pre-slaughter and slaughter stressful practices could have an important effect on the flesh quality in fish. A clear effect emerged mostly on the physical properties of flesh, because severe stress at slaughter time exhausted muscular energies, produced more lactic acid, reduced muscular pH, increased the rate of rigor mortis onset. In this way they could have significant negative effects on technological traits, flesh quality and keeping quality of fish. Asphyxia and electrically stunned fish were more stressed than spiked, knocked and live chilled fish. Combining various methods together might be a more satisfactory strategy for both animal welfare and product quality.
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... Acute stress responses during capture and slaughter can induce a cascade of physiological changes in the fishes' muscle tissues (e.g. elevated catecholamine, cortisol and lactate concentrations, reduced pH and depleted ATP inducing early onset and strengthened rigor mortis) that can detrimentally affect the quality and shelf life of seafood products [41]. As ABT are highly oxyphilic with a large anaerobic and thermoregulatory capacity, they are particularly susceptible to stress induced quality reductions [42]. ...
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