Increasingly, perches for laying hens are being made from metals and plastics. There is nothing in the literature regarding how easily birds jump between perches of different materials, or how their ability to do so changes with faecal contamination of the perches. Forty-four medium hybrid brown hens negotiated perches of wood (5 cm × 5 cm, rounded edges), metal (half-round section, diameter 4 cm) or poly-vinyl-chloride (PVC: circular section, diameter 4 cm), which were either clean or dirty (poultry manure 0.5–1.0 cm deep). The time to jump to the destination perch (0.75 m from the start perch), number of squats (pre-jumping behaviour), slips, failures to jump (in 300 s) and crashes were recorded. Compared to wood and metal perches, birds took significantly longer to jump from PVC perches when they were clean, but there was no difference when the perches were dirty. Birds slipped significantly more on clean metal or PVC perches compared to clean wood perches. The birds took significantly longer to jump from metal or wooden perches when they were dirty compared to when they were clean. These data may suggest that PVC is not a suitable material for perches. Slipperiness is important. The birds apparently found the metal and PVC perch more slippery than the wooden perch, although the metal perch did not cause the birds to delay jumping. A slippery perch may deter the birds from attempting to jump. Manure on the perches reduced the slipperiness of the metal and PVC perches. Once perches become dirty, any welfare issues concerning the risk of injury from slippery perches cease to be as important as the potential slipperiness of the manure itself.

Research into the responses of hens on perches is important in order to assess the welfare impact of alternative systems for egg production which incorporate perches in their design. Previous studies suggest that many flight and landing accidents occur in such systems as birds attempt to move between perches and facilities, resulting in a high incidence of bone breakage. In this study three horizontal perches were set with a gradient between them of 0, 30, 45 or 60 degrees according to treatment. Four groups of 15 ISABrown laying hens were individually exposed to each treatment, being placed on the uppermost perch (Perch 1) with a food reward available at the lowest perch (Perch 3). Behaviours performed before reaching Perch 3 were recorded over time. More birds failed to move to Perch 3 in 10 minutes when perches were separated by 45 or 60 degrees. In birds which stayed on the perches for the full 10 minutes, without reaching Perch 3, downward head movements, calling, intended jump behaviours, side-stepping and wing-flapping decreased significantly with time spent on the perches. Motivation to complete the task, in order to gain the food reward, was high in all treatments. However, when birds found perches difficult to negotiate, behaviours indicating intention to move to the food decreased with time and the incidence of behaviours indicating frustration and thwarting increased. In non-cage systems such frustration could reduce bird welfare.

Non-cage systems for housing laying hens often incorporate a framework of perches, allowing birds to move in three dimensions. Wood is predominantly used for perch construction, because it is relatively cheap and easy to work with. However, wooden perches are difficult to clean and disinfect, which could lead to disease and discomfort for the birds using them. The objectives of this study were to identify which characteristics of perch design are preferred by laying hens; and to test whether birds would use perches of alternative materials for a comparable amount of time as they use wooden perches. Six laying hens were housed individually in litter-floored pens and were offered a choice of three pairs of contrasting perch types (experiments 1-3): a rectangular, wooden perch (‘control’) versus two, thin, parallel, rectangular wooden perches; ‘control’ versus a similar perch covered with foam and fabric; and ‘control’ versus a round, wooden perch. Birds were given each pair of perches twice, controlling for perch position in the pen. Time spent on each perch in a 48h period was determined from video records. Preferences were then tested in consecutive trials (experiments 4-5) between perches of the following materials: wood versus plastic versus steel; and wood versus textured aluminium. There were no significant differences in time spent on different perches, suggesting that birds had no preferences between perch types. The implications of these results could be important for the design of alternative systems for laying hens. Birds may be content to perch on artificial materials which could be more hygienic than wood and easier to maintain in a commercial system.

Free-living hens perch on branches in trees and domestic hens (Gallus gallus domesticus) show signs of unrest if they cannot reach a perch, suggesting that night-time perching is a behaviour that hens are motivated to perform. This motivation was quantified in two experiments using a weighted push-door that hens had to push open in order to gain access to a perch. First, the motivation of individual birds to perch, and second, the effect of a companion bird on perching motivation, were measured. Eight adult laying hens (Lohmann Selected Leghorn) were trained to push through the door at increasing resistances, and the individual capacity of each hen was determined. Hens were then tested once per day, at lights-off in a test pen where pushing through the push-door gave access to the resource. Two consecutive series of increasing resistances were used in the experiment: 25, 50, 75 and 100 per cent of each bird's maximum capacity. In the first experiment, the resources offered were either a perch (treatment) or a ‘sham perch’ that could not be used for perching (control). Hens opened significantly heavier doors in order to gain access to a perch than to gain access to the sham perch. In the second experiment, pushing through the door gave access either to a perch with a companion hen already perching on it (treatment) or to a perch and a companion hen roosting on the floor (control). In this comparison, four of the hens did not push through the door, probably because of aggressive interactions with the companion, and no significant differences between treatments were found. We conclude that hens are motivated to use a perch for night-time roosting and that they should be housed in systems with perches.

Commercial broiler production systems based on market initiatives to improve animal welfare beyond minimum legal requirements have emerged in several European countries. A common factor in the ‘higher welfare’ indoor systems is the application of environmental enrichment, with or without natural light, to promote locomotor activity and natural behaviours of the broiler chickens. In the current study, we evaluated the effects of a commercial enrichment programme for fast-growing indoor-housed broiler chickens, with or without natural light entering the broiler house. Enrichment materials were selected in relation to perceived minimal hygiene risk and ease of cleaning in between production cycles. Selected enrichments were a combination of wood shavings bales (1.5 bale/1000 chickens), round metal perches (2.7 m/1000 chickens) and metal chains as pecking objects (1/1000 chickens). Three treatments were studied: control (C) without enrichment and natural light, enriched (E) with enrichments as previously defined but without natural light and enriched plus natural light (EL) with enrichments as previously defined and natural light entrance. The experiment was carried out during five subsequent production cycles on one commercial broiler farm with three identical houses. EL could only be assigned to the middle house that was equipped with roof windows (light entrance area: 3% of floor space). C and E were in the two outer houses (alternated in between production cycles). Behaviour was observed during daytime at days 25 and 39 of age by scan sampling. Lameness, footpad dermatitis, hock burn, cleanliness and injuries were scored at the same ages, in addition to the response of the chickens to a novel object. Results showed that the treatments only affected broiler behaviour. E flocks showed significantly more resting as compared with EL and C. EL flocks showed significantly more walking, exploration and foraging behaviour as compared with E and C. Thus, broiler activity was highest in the EL treatment and lowest in the E treatment, with the C treatment in between. No treatment effects were found on the other welfare indicators and only a few tendencies for treatment effects were found for the novel object test, with E birds tending to be more reluctant to approach the object as compared with EL and C birds. We concluded that providing environmental enrichment and natural light-stimulated activity and natural behaviours in broiler chickens, whereas providing enrichment only seemed to have the opposite effect as compared with control flocks without enrichment.

The aim of this study was to assess the effect of providing environmental enrichment in the form of perches and string on the behaviour and welfare of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of four treatments in a 2×2 factorial design. Treatments involved two levels of access to perches (P) (present (24/house) ‘+P’ or absent ‘−P’) and two levels of access to string (S) (present (24/house) ‘+S’ or absent ‘−S’). All houses contained windows, and 30 straw bales were provided from day 10 of the rearing cycle. Treatments were applied in one of four houses on a single farm, and were replicated over four production cycles. Behaviour and leg health were observed in weeks 3 to 5 of the rearing cycle. Production performance and environmental parameters were also measured. There was an interaction between perches and age in the percentage of birds observed lying, with higher percentages of birds observed lying in the +P treatment than in the −P treatment during weeks 4 and 5. There was also a significant interaction between string and age in the percentage of birds observed in locomotion, with higher percentages observed in locomotion in the −S treatment than in the +S treatment during weeks 4 and 5. There was also an interaction between string and age in average gait scores, with lower gait scores in the +S treatment than in the −S treatment during weeks 3 and 5 but not within week 4. Daytime observations showed that perches and strings were used frequently, with one bout of perching occurring approximately every 80 s/perch, and one bout of pecking at string occurring every 78 s/string on average. There was a significant effect of age on use of perches (P<0.001) and string (P<0.001), with perching peaking during week 5 and string pecking peaking during week 3. We conclude that commercial broilers in windowed houses with access to straw bales display an interest in additional enrichment stimuli in the form of perches and string, and therefore that these stimuli have the potential to improve welfare. In addition, provision of string as a pecking device appeared to positively influence walking ability. However, this effect was numerically small, was only shown in certain weeks and was not reflected in the other leg health measure (latency to lie). The results also showed an apparent negative effect of string and perches on the activity levels of birds (recorded away from the immediate vicinity of these enrichments) towards the end of the production cycle. These results emphasise the need for further research into optimum design and layout of enrichment stimuli for modern broilers in windowed houses to ensure that their provision leads to clear welfare benefits.