Evaluating the impact of electrical stunning on the welfare and meat quality of the American lobster ( Homarus americanus )

Abstract

Sentience in decapod Crustaceans has emerged as a major topic within animal welfare, partly due to a lack of legislation that protects their well-being, particularly at the moment of killing. Electrical stunning has been proven to prevent, or minimise, pain and distress prior to dispatch. Investigating its effects on behaviour, physiology, and meat quality is essential for informing future legislation. This study tested the impact of Crustastun ^TM electrical stunning on the American lobster ( Homarus americanus ) in order to: (i) determine the effect of two stunning durations (5 vs 10 s) on the recovery and behaviour; (ii) assess physiological alterations caused by stunning and during recovery; and (iii) evaluate impacts on meat quality. Lobsters showed longer righting times with 10 s stunning compared to 5 s, along with increased activity during recovery. Electrical stunning caused sustained disturbances in haemolymph glucose and lactate levels. Overall meat quality was unaffected, except texture, which was improved in stunned animals. Based on the recovery, this study demonstrated the reversibility of Crustastun ^TM , distinguishing it from a terminal dispatch method. Stress induced by electrical stunning was evidenced by the elevated haemolymph lactate levels, highlighting this measure as an indicator of secondary stress responses. The reversibility implies that animals should be slaughtered before any signs of recovery which, based on the righting response, should be no later than 10 min after short and 40 min after long cycles. However, the duration of unconsciousness should be confirmed using other indicators of consciousness, ideally based on neural activity.