SUSTAINABILITY, ENERGY AND ANIMAL WELFARE AT SLAUGHTER

The PhD project Sustainability, Energy and Animal Welfare at Slaughter (Sostenibilità, Energia e BEnessere alla Macellazione – SEBEM) aimed to enhance the sustainability of sheep production systems by establishing high standards of animal welfare at slaughter and developing innovative strategies for managing slaughter waste. Animal welfare during slaughter raises critical ethical and sustainability questions in livestock production. EU legislation mandates the use of animal-based measures (ABMs) to assess stunning effectiveness and ensure animals do not regain consciousness until the death. While the 2021 EFSA Scientific Opinion on the “Welfare of Sheep and Goats at Slaughter” provides a list of ABMs for electrical and mechanical stunning (e.g., breathing, posture, tonic-clonic seizures, muscular tone, vocalisations, eye movements, reflexes, and blinking), their practical feasibility remains poorly explored. Variations in slaughterhouse facilities and operations – from small abattoirs to industrial settings – further complicate the application of these indicators. This gap underscores the need for research efficiently apply ABMs in different contexts. To address these challenges, this PhD project introduces innovative strategies for monitoring sheep welfare at slaughter considering the small (or familiar) and the industrial (or large) context. These studies aimed to investigate the feasibility of ABMs capable of efficiently detecting signs of consciousness and unconsciousness in lambs. Key parameters considered included electrode positioning, the duration of current application, and the stun-to-stick interval under field conditions. The project comprises three key studies: • Study 1: A systematic review critically evaluated the feasibility of ABMs for assessing stunning effectiveness and unconsciousness in sheep • Study 2: A checklist was developed and tested to assess the feasibility of signs of consciousness and unconsciousness in small abattoirs. Direct observations were conducted on 34 lambs individually stunned with a penetrative captive bolt in a small slaughterhouse in Northern Italy. • Study 3: A on-field study investigated signs of consciousness following head-only electrical stunning in 3047 lambs, using video analysis to correlate these signs with the effectiveness of the stunning process in an industrial abattoir. The systematic review revealed limited research on the practicality of ABMs in both small and industrial settings, highlighting the need for further investigation. Regarding the small contest, feasible indicators observable from a distance included tonic and clonic convulsions, fixed eyes, eyeball rotation, nystagmus, relaxed jaws, righting reflex, and vocalisations. Collapse was feasible only when lambs lost their quadrupedal stance immediately after stunning without restraint. Indicators such as apnoea, blinking, tongue protrusion, and voluntary kicking were deemed unfeasible due to poor visibility. A limitation of this study was its focus on a single slaughterhouse, a specific animal category, and the small sample size, restricting broader comparisons. While, in industrial context, results indicated excessively long stun-to-stick intervals and the presence of several signs of consciousness. Correlations were found between ABMs observable in the head area, emphasising its importance as a critical hotspot for monitoring multiple indicators of stunning efficacy. Although these findings cannot be generalised due to the limited sample considered, that could be useful as a starting point, for identifying optimal combinations of feasible ABMs capable of efficiently detecting signs of consciousness in lambs in a small and industrial abattoirs, and enhancing sheep welfare.