WELFARE ASSESSMENT OF PIGS IN THE TIME OF SLAUGHTER - STUNNING QUALITY AS A WELFARE INDICATOR

Abstract

Maintaining the welfare of pigs is important during all stages of breeding, including the slaughtering process itself. This process is one of the most critical points for impairing their welfare, which further leads to changes in meat quality. In order to sustain the welfare of pigs during slaughtering there are specific welfare criteria that needs to be fulfilled. The objective of this study was to assess the welfare of pigs during slaughtering with the method of electrical stunning. The welfare assessment was performed on 215 pigs in three slaughterhouses. In order to perform the assessment, the following parameters were measured: duration (seconds, s) of application of the electric current (AD), electric current (amperes, A), electric potential (voltages, V), time (s) from AD to bleeding, corneal reflex, rhythmic breathing, vocalization and righting reflex. These measures are in line with the “Assessment pig protocol” (chapter 6.3 – Collection of data for finishing pigs at slaughterhouse), derived from the Welfare Quality® project. The results of the obtained data from all of the observed pigs show that the average AD was 7.88s (range from 2.15s – 18.89s), the average time from AD to bleeding was 5.49s ± 2.31s (range from 0.67s – 18.95s), the average electrical current was 2.07A ± 0.49A (range from 1.29A – 3.09A) and the average electrical tension was 265V ± 13V (range form 237V – 296V). Regarding the quality of stunning, 37.2% of pigs had positive corneal reflex right after stunning, 20% had rhythmic breathing, vocalization was observed in 7.4% and 2.8% of the pigs showed positive righting reflex. Differences were detected between the slaughterhouses in terms of the observed parameters, including the total sum of AD and the time from AD to bleeding. The average total sum of AD and time from AD to bleeding was 10.2s, 15.2s, and 13.9s in each of the slaughterhouses separately (p<0.05). These differences between slaughterhouses indicate different stunning and slaughter practices among them. Analysis of the data obtained from the welfare quality parameters for stunning, points out impairment of animal welfare during slaughtering and urges an immediate action in improving of stunning process in slaughterhouses.