PSIII-16 Evaluating the impact of group stunning on physiological parameters of pigs in a small abattoir
Abstract Small abattoirs commonly process pigs and sheep in a handling system designed for cattle. Smaller species are usually stunned in groups in the cattle shackling area in front of the stun box. The purpose of this study was to determine the effects of stun order on physiological parameters in pigs. A total of 148 barrows and gilts were stunned in 29 groups of four to five pigs with seven control pigs. All pigs were moved together into the stunning pen and stunned one at a time with a handheld penetrating captive bolt stunner and immediately shackled and processed. The average time from pen entrance to the final stun was 22 minutes. To act as a control, one pig was moved into the pen individually and stunned after the same elapsed time as the groups. Blood lactate and glucose concentration were measured in exsanguination blood using hand-held analyzers. A one-way ANOVA was used to determine the effect of stun order on blood metabolite concentration. Pigs stunned first had significantly greater lactate than the last pigs stunned (P < 0.01). Stun order did not have a significant effect on blood glucose concentration (P = 0.43). The control pigs had significantly lower lactate than the first pig stunned (P = 0.04). Greater blood lactate concentrations in the first pig may be due to handling into the stunning pen prior to the first stun. Handler interaction may have resulted in an increase in certain behaviors such as turning back and squealing which further caused the first pigs to have increased lactate.