Effects of rearing conditions on behavioural and physiological responses of pigs to preslaughter handling and mixing at transport

The physiological and behavioural responses of slaughter pigs reared in eit her a barren environment or in an enriched environment (larger pens with st raw bedding) to preslaughter handling and mixing at transport were studied. Enriched-reared pigs had higher salivary cortisol concentrations in the ho me pen before and after transport than barren housed pigs, but at the end o f the lairage period salivary cortisol concentrations did not differ betwee n enriched- and barren-housed pigs. In pigs reared in a barren environment, salivary cortisol concentrations increased significantly after transport a nd being in lairage, as compared to home pen salivary cortisol concentratio ns. In pigs reared in an enriched environment, salivary cortisol concentrat ions did not significantly change after any stage of preslaughter handling and transport as compared with home pen salivary cortisol concentrations. I n the truck, pigs reared in a barren environment tended to spend more time walking, standing and manipulating other pigs than enriched-reared pigs. Mo reover, pigs reared in a barren environment tended to spend more time walki ng and fighting in lairage than enriched-reared pigs. Results showed that r earing conditions may affect the behavioural and physiological responses of pigs to preslaughter handling and mixing at transport. The tendency for in creased manipulation of pen mates and fighting, and the significant increas es in salivary cortisol in response to mixing at transport and being in lai rage in pigs reared in a barren environment indicate that pigs reared in a barren environment are likely to experience more stress during common presl aughter procedures than pigs reared in an enriched environment.