Effects of panels and perches on the behaviour of commercial slow-growing free-range meat chickens

Environmental enrichment has the potential to benefit the welfare of farm animals. In poultry, panels and perches are two of the most commonly used forms of enrichment but few studies have determined their effects under commercial conditions. The aim of this work was to assess the impact of these forms of enrichment on the behaviour of slow-growth free range meat chickens. The study was conducted in four commercial farms each with 3900 birds, housed in three independent houses with access to an outdoor area. One house in each farm was outfitted with indoor and outdoor panels, the second with perches, and the third house was used as a control and had no enrichment. In each house 40 birds were tagged for individual recognition. Focal observations were performed from 6 to 12 weeks of age, with thirty 5 min focal samples collected in each house in the indoor and outdoor areas alternatively. In addition, the location (in XY coordinates) of tagged birds inside and out, and their behaviour, was also collected. We did not find a main effect of treatment on the behaviour inside or outside the house (P>0.05). However, the interaction between treatment and week of age for standing (P<0.05) indicated a general increase with week of age only for the perch treatment inside the houses, and for only the perch and control treatments in the outdoor area (P<0.05). Resting decreased until week 9, while locomotive behaviours increased until week of age 10 in the outdoor area (P<0.05), with both trends reversing afterwards. A higher percentage of birds performed locomotive behaviours more often in the central area of the house in the panel treatment as compared to the control (P<0.05), with perch treatment showing intermediate values. Overall, environmental complexity had a limited effect on the behaviour of slow-growth meat chickens, although the perch presence translated into a higher percentage of standing. It is likely that the reduced effects of the environmental enrichment treatments would have been greater if more devices were introduced. (C) 2015 Elsevier B.V. All rights reserved.