Behavioural development of pigs with different coping characteristics in barren and substrate-enriched housing conditions

Characterization of piglets based on the degree of resistance they display in a so-called Backtest is, to a certain extent, predictive of their coping responses to several challenges in later life. It is unknown, however, whether these individual coping characteristics of pigs are also reflected in their behavioural development in different environments. The present study investigated the behavioural development of pigs with diverging Backtest responses, high-resisting (HR) and low-resisting (LR) pigs, in both barren housing and housing enriched with straw bedding. During the suckling period, pigs were subjected to the Backtest. Pigs classified as HR (n = 30) or LR (n = 30) were selected and after weaning housed in groups of six (three LR and three HR) in either barren or enriched pens. Home pen behaviour was recorded at 5, 9, 15 and 19 weeks of age for 8 h per week using 2-min instantaneous scan sampling. Housing environment markedly influenced behaviour of pigs. Barren housed pigs were less active, showed less explorative and play behaviour, and spent more time on oral activities directed at pen mates than pigs from enriched housing. HR pigs showed more aggressive behaviour than LR pigs and they tended to be less active in both environments. LR pigs spent more time on manipulating pen mates, in particular in barren housing. In addition, they played more than HR pigs in enriched pens. In conclusion, an enriched housing environment, i.e. availability of straw bedding, appeared to improve welfare as it increased play behaviour and decreased manipulative oral behaviour directed at pen mates in comparison with barren housing conditions. Individual coping characteristics of pigs, as assessed in the Backtest, were also reflected in their home pen behaviour. Notably, the effects of housing on both manipulative and play behaviour were most obvious in LR pigs