Review Of The Main Welfare Risks Related To Electrical Stunning Of Small Ruminants (Ovine And Caprine Species)
EFSA commissioned a comprehensive review of the welfare aspects of electrical stunning methods for small ruminants with an emphasize on low ampere stunning to establish the state of the art in the field and to assess whether scientific studies would address criteria outlined in an EFSA guidance on the assessment criteria for studies evaluating the effectiveness of stunning interventions regarding animal protection at the time of killing (EFSA Journal 2013;11(12):3486). The review was not formulated as a systematic review with a focused question instead the review followed the approach to assessing the literature described by the EFSA guidance. The key databases searched were: Science Citation Index (1900-2014), CAB Abstracts (1910-2014) and Medline (1990-2014). Key conferences proceedings and the bibliographies of review articles were manually searched. The search yielded 1599 records. 706 duplicate records were removed and 894 records assessed for relevance. Relevant studies reported electronic stunning of small ruminants and outcomes associated with onset and duration of unconsciousness. Eighteen papers reported electrical approaches to stunning in sheep. No goats were studied. None of the papers reported all of the parameters detailed in the EFSA guidance (EFSA, 2013) and a risk of bias assessment was not conducted. No studies reported the appearance of the electrodes. When the frequency (Hz) applied to the animal was reported, it was not specified whether this represented a minimum or maximum frequency. Only one study explicitly reported an effect size for amperes. The study suggested that the odds of a poor stun were higher for amperes of 0.6 (odds ratio (OD) of 6.27 with 95% confidence interval (CI) of 1.98-20.7) and 0.8 (OR of 24.4 with 95% CI of 6.98-85.2) when compared to a poor stun at 1.25 ampere.