Stunning and slaughter methods in gilthead seabream: Animal welfare and muscle quality
海鲷的致昏和屠宰方法：动物福利和肌肉质量
Abstract
European Union directives and international guidelines emphasise the need for humane slaughter practices, with particular attention to the proper stunning of fish prior to slaughter. This study investigates the impact of various combinations of stunning and slaughter methods on the welfare of gilthead seabream (Sparus aurata), a widely farmed species in the Mediterranean and Black Sea regions. Specifically, the study explores electrical stunning, anaesthesia, and no stunning, followed by slaughter using either ice-slurry or the ikejime (hand-held spike tool) technique. Fish were monitored for visual signs of consciousness, heart rate, internal temperature, plasma stress and osmotic parameters, and muscle quality parameters. The findings revealed that electrical stunning, although inducing brief unconsciousness, did not sustain it long enough to be effectively combined with ice-slurry, resulting in stress responses and muscle quality parameters comparable to those observed in unstunned fish. In contrast, anaesthesia effectively reduced stress and improved meat quality. The ikejime technique, despite its labour-intensive nature, demonstrated significant advantages, including reduced physiological stress and superior muscle quality outcomes. These results suggest that the viability of electrical stunning as a humane option for industry implementation has important limitations, while ikejime, with further refinement and automation, could offer a humane and effective solution to optimise both animal welfare and meat quality in industrial settings.
欧盟指令和国际准则强调了人道屠宰做法的必要性，特别注意在屠宰前对鱼类进行适当的电击。本研究调查了电击和屠宰方法的各种组合对地中海和黑海地区广泛养殖的物种金鱼鲷（Sparus aurata）福利的影响。具体而言，该研究探讨了电击、麻醉和非电击，然后使用冰浆或ikejime（手持刺入工具）技术进行屠宰过程中，监测鱼类的意识视觉体征、心率、体温、血浆压力和渗透参数以及肌肉质量参数。研究结果表明，电击虽然会导致短暂的昏迷，但并不能持续足够长的时间，无法与冰浆有效结合，从而导致应激反应和肌肉质量参数与未经电击的鱼类相当。相比之下，麻醉有效地减轻了压力，提高了肉质。尽管ikejime技术具有劳动密集型的性质，但它显示出显著的优势，包括减少生理压力和提高肌肉质量。这些结果表明，电击作为工业实施的人道选择的可行性存在重大局限性，而ikejime通过进一步的改进和自动化，可以提供一种人道有效的解决方案，以优化工业环境中的动物福利和肉类质量。
Keywords
Compassionate killing，Aquaculture Animal care，Unconsciousness，Alternative methods
