Untitled

Abstract

Fish welfare at slaughter is an area of considerable scientific and commercial importance during the last decade. The aim of this study was to evaluate the effect of three stunning procedures on stress and meat quality of common carp. The experimental fish were separated in three groups and stunned by percussion (Group PS), electricity (Group ES) or asphyxia (Group AS), followed by decapitation. Blood cortisol and glucose concentrations were measured as stress indicators, whereas drip loss was used as meat quality parameter. The lowest glucose concentration (3.86±1.26 mmol/L) and drip loss (2.02±0.42%) were observed in Group PS. On the contrary, Group AS showed the highest results (11.34±3.07 mmol/L and 3.22±0.75% for blood glucose and drip loss, respectively), whereas the electrically stunned carp took an intermediate position (6.05±1.29 mmol/L and 2.29±0.43%). We conclude that percussive stunning leads to considerable reduction of stress at slaughter and better meat quality (lower drip loss), whereas asphyxia is unacceptable method due to the strong stress reaction and increased drip loss. Electrical stunning can be an effective method for stunning carp, but requires improvements of the electrical device to eliminate the repeated current application.

Farmed fish welfare: stress, post-mortem muscle metabolism, and stress-related meat quality changes

“…As it was discussed by Daskalova et al (2016b), the impairment of water-holding capacity is of great importance, as it is substantial in commercial processing practice. Water-holding capacity is an essential fresh meat property, because it affects the yield and quality of the end product.…”

Physiological stress and meat quality of pacu (Piaractus mesopotamicus) submitted to CO2narcosis, hypothermia and electrical stunning

“…One of the most critical steps in fish welfare occurs in the slaughter phase, with hormonal, biochemical, osmoregulatory and energetic alterations. These changes can affect the meat quality, with changes in colour and texture of the fillets, protein degradation, and lipid and metabolic oxidation (Daskalova et al,2016; Zampacavallo et al, 2015).…”

“…

One of the most critical steps in fish welfare occurs in the slaughter phase, with hormonal, biochemical, osmoregulatory and energetic alterations. These changes can affect the meat quality, with changes in colour and texture of the fillets, protein degradation, and lipid and metabolic oxidation (Daskalova et al,2016;Zampacavallo et al, 2015).Various methods for stunning and killing fish have been studied, such as electrical current application, cranial percussion, hypothermia, asphyxiation, CO 2 narcosis, anaesthesia, and spiking. Among these methods, stunning by hypothermia has been one of the most used by the fish industry (Zampacavallo et al, 2015; Oliveira Filho, Oliveira, et al, 2015a; Oliveira Filho, 2015b).

…”

Unconsciousness assessment through electroencephalography (EEG), in the process of stunning, for electronarcosis, percussion and anaesthesia for humane slaughter of Nile tilapia

“…The lack of a clear stress response for cortisol in fish has been previously reported. The common carp (Cyprinus carpio L.) stunned by percussion, showed the lowest average glucose concentration in the blood plasma (87 ng/mL; 16-665) (median: Q1-Q3) as compared to fish stunned by electricity (800; 14-800) and asphyxia (800; 800-800) (Daskalova et al, 2016). Daskalova et al (2016) reported serious difficulties in statistical processing and the inability to calculate averages due to the cortisol values, and the authors attributed such differences to individual neuroendocrine and behavioural differences.…”

“…The common carp (Cyprinus carpio L.) stunned by percussion, showed the lowest average glucose concentration in the blood plasma (87 ng/mL; 16-665) (median: Q1-Q3) as compared to fish stunned by electricity (800; 14-800) and asphyxia (800; 800-800) (Daskalova et al, 2016). Daskalova et al (2016) reported serious difficulties in statistical processing and the inability to calculate averages due to the cortisol values, and the authors attributed such differences to individual neuroendocrine and behavioural differences. In several cases a high biological variability in cortisol values was reported amongst individuals submitted to the same experimental conditions, suggesting that cortisol measurements should be complemented by other metabolic indicators to validate its results (Magalhães et al, 2018).…”