Evidence for litter differences in play behaviour in pre-weaned pigs.

The aim of this study was to analyse spontaneous play behaviour in litters of domestic pigs () for sources of variation at individual and litter levels and to relate variation in play to measures of pre and postnatal development. Seven litters of commercially bred piglets ( = 70) were born (farrowed) within a penning system (PigSAFE) that provided opportunities for the performance of spontaneous play behaviours. Individual behaviour was scored based on an established play ethogram for 2 days per week over the 3 week study period.