Twenty pregnant sows sharing a double-entry back-out Pig Code feeder with a similar group of 20 were observed over six 24-h feed cycles by a combination of direct observation and video recording. The group had access to an area of 47 m 2 . Sows were fed once a day on a pelleted diet and water was continually available. Feeding order was relatively constant from day to day, and was positively correlated with parity. A social hierarchy based on displacements and attacks within pairs of sows was found to be basically linear, with the exception of six reversals of dominance. Social hierarchy was positively correlated with feeding order overall, but this was not the case for the latter half of the feeding order. This was partly due to disruption of feeder use by non-feeding visits made by earlyfeeding dominant sows. Overall the results showed that older sows with more experience of the feeder in two or three previous parities were higher in the feeding order and social hierarchy than younger sows, and may exclude them from the feeder by repeated non-feeding visits.
Pigs from four farms (two producing 'easy' and two 'difficult to handle' pigs) were slaughtered at two abattoirs, each with two slaughter handling systems, so that 25 pigs of each behavioural type were slaughtered by all four handling systems on each day; there were 16 replicates (3200 pigs) in total. The pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y the pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. The following measurements were made: hot carcase weight and backfat thickness at P2, degree of rigor mortis 35 minutes post mortem, skin blemish, pH and muscle reflectance in the m longissimus dorsi at 60 minutes and 18 hours post mortem, and pH and muscle reflectance in the m adductor at 18 hours post mortem. At abattoir X, the pigs slaughtered in the race-restrainer had heavier carcases (74.0 kg vs 73.0 kg, P < 0.05), developed rigor mortis more rapidly (8.1 mm vs 7.3 mm, P < 0.01), had more skin blemish (2.8 vs 2.7, P < 0.01), paler m longissimus dorsi muscles after one hour (15.7 vs 13.9, P < 0.01) and 18 hours (27.8 vs 26.6, P < 0.05), and paler m adductor muscles (24.5 vs 22.7, P < 0.001) after 18 hours. At abattoir Y, the pigs handled through the floor pen system had more skin blemish (2.7 vs 2.6, P < 0.05) and a tendency to develop rigor mortis more quickly (6.11 vs 5.32, P = 0.089).(ABSTRACT TRUNCATED AT 250 WORDS)
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