The effects of handling and group size on welfare of pigs in lairage and their influence on stomach weight, carcass microbial contamination and meat quality

Abstract

At unloading and on the way to stunning, 800 barrows were exposed to either gentle handling (GH: slowly with a plastic board or whip) or rough handling (RH: quickly with an electric prod). Pigs were kept in large or small groups (30 or 10 pigs) during lairage. Compared with GH, RH increased climbing (P < 0.05), slipping (P < 0.01) and turning around (P < 0.001) behaviours during unloading, and climbing (P < 0.05) on the way to stunning. RH also reduced drinking behaviour during lairage (P < 0.01). Pigs kept in large groups were observed more often standing (P < 0.05) and fighting (P < 0.001) than pigs kept in small groups, but, in contrast, had a slightly lower level of urinary cortisol at slaughter. Stomach weight and microbial contamination at slaughter were not affected by treatments. RH tended to increase skin bruise score on the carcass (P < 0.06) and produced more exudative meat (P < 0.05). In conclusion, the response of pigs to the two specific stressors applied prior to slaughter in this study did not seem to contribute to stomach weight variation at slaughter, but it did influence pork quality. Key words: Pigs, pre-slaughter handling, group size, stress, stomach weight, microbial contamination, behaviour, meat quality