Influence of different types of environmental enrichment on the behaviour of finishing pigs in two different housing systems: 1. Hanging toy versus rootable substrate

This study aimed to assess the effects of environmental enrichment with either hanging manipulable toys or rootable substrates on the behaviour of finishing pigs in two contrasting housing systems. Thousand one hundred and twenty-four (Large White × Landrace) × Large White pigs were housed contemporarily in either a straw-based (ST) or fully slatted (FS) building from 35 kg to slaughter at 104 kg liveweight. In each building, half the pens received additional enrichment in the form of a hanging plastic toy (Bite-Rite). In the ST house the remaining pens were enriched only by the straw bedding. The remaining pens in the FS house were provided with hoppers containing shreds of unmolassed sugar beet pulp. The level of Bite-Rite manipulation was significantly higher in the FS system than in the ST system (P < 0.05). Within the FS system, the sugar beet pulp occupied the pigs for more time than the Bite-Rite object (P < 0.05). Neither object provided a level of occupation close to that of straw bedding in the ST system. In the absence of straw, more investigatory behaviours were directed towards pen components (P < 0.001), however, no significant differences in pig-directed behaviours were observed. Further study is required to identify functional forms of environmental enrichment for pigs in unbedded systems.