Effects of pen size, partial stalls and method of feeding on welfare-related behavioural and physiological responses of group-housed pigs

The effects of space allowance (1.97 or 0.98 m 2 per pig), partial stalls (presence or absence) and a feeding regimen either within the stalls or on the floor on the welfare of pigs housed in groups of four was examined in an experiment involving 96 pregnant gilts (Large White × Landrace). Welfare was assessed on the basis of skin lesions, changes in social behaviour that may affect welfare (e.g. aggression), the magnitude of any chronic physiological stress response and a measure of cell-mediated immunity. The spatial utilization of the pens by pigs was also observed. The behaviour observations were made when the pigs were initially grouped and over the subsequent 4 weeks. The cortisol concentrations were measured in the fourth and seventh to eighth weeks in treatment; cell-mediated immunity was measured at the end of the experiment In the 90 min following grouping of the (unfamiliar) pigs, the presence of the partial stalls in the pens reduced the number of aggressive interactions ( P