Influence of housing conditions on responses of pigs to preslaughter treatment and consequences for meat quality

Abstract

The effects of housing conditions on behavioural and cortisol responses during preslaughter treatment, as well as the consequences for meat quality, were studied in 48 slaughter pigs. Pigs were either raised in intensive housing conditions ("standard" treatment: standard farrowing crates (4.2 m2) followed by standard rearing pens (0.5 m2/pig) and fattening pens (0.8 m2/pig) or in extensive conditions ("enriched" treatment: larger farrowing pens (7.2 m2) followed by larger rearing and fattening pens (both 1.2 m2/pig), all provided with straw).No differences in behaviour during transport or in any of the meat quality variables were found between treatments. During pre-slaughter handling, stockmen needed significantly less time to load pigs from standard housing conditions (standard: 56.8 ± 11.9 s; enriched: 93.7 ± 12.5 s). Standard pigs may have been more motivated to leave their pens in order to explore another environment than pigs from the enriched housing pens. Rise in salivary cortisol levels due to transport (standard: 6.68 ± 0.80 ng mL−1; enriched: 3.63 ± 0.58 ng mL−1) was difficult to interpret as omission of straw during the hours prior to transport apparently led to high baseline cortisol levels in enriched pigs (8.63 ± 1.27 ng mL−1 vs. 2.60 ± 0.37 ng mL−1 in standard pigs). The extensive housing system should be preferred as it is known to have positive effects on pig welfare, and does not lead to impaired meat quality. Key words: Behaviour, housing, meat quality, physiology, pigs, slaughter