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Effects of perch design on behaviour and health of laying hens

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Abstract

EU-Directive 1999/74/EC stipulates that furnished cages and non-cage systems for laying hens should be provided with perches. This Directive allows for a wide variety in perch design features possibly affecting perch use and hen health. Perch material and shape mainly affect slipperiness and grip quality and, in this regard, plastic, metal and circular perches are inferior. The incidence of bumble-foot and keel bone deformities can be influenced by perch shape. Perch shapes which reduce localised pressure on the foot pad and the keel-bone are recommended. Several aspects of the arrangement of the perches in the cage or non-cage system are also important. A consistent preference for high perches is seen, provided there is a minimal distance of 19–24 cm between perch and roof. Accessibility of high perches should be ensured, for example by incorporating lower level perches from which hens can reach the higher levels. Such multi-height perch designs also allow behavioural differentiation according to perch height (with most passive behaviour on the higher perches). In non-cage systems, good accessibility can be achieved by minimising the angles between perches at different heights to smaller than 45° and by limiting the distance between horizontal perches to 1 m. The legislated minimum perch length provided per hen (15 cm) adequately allows for synchronised roosting behaviour on straight perches. However, in crosswise perch designs, hens require more perch length per hen as the area close to the cross cannot be used optimally.
533
© 2009 Universities Federation for Animal Welfare
The Old School, Brewhouse Hill, Wheathampstead,
Hertfordshire AL4 8AN, UK
Animal Welfare 2009, 18: 533-538
ISSN 0962-7286
Effects of perch design on behaviour and health of laying hens
E Struelens*and FAM Tuyttens
University College Ghent, Department of Biosciences and Landscape Architecture, Brusselsesteenweg 161, 9090 Melle, Belgium
Animal Sciences Unit, Institute for Agricultural and Fisheries Research, Scheldeweg 68, 9090 Melle, Belgium
* Contact for correspondence and requests for reprints: ester.struelens@hogent.be
Abstract
EU-Directive 1999/74/EC stipulates that furnished cages and non-cage systems for laying hens should be provided with perches. This
Directive allows for a wide variety in perch design features possibly affecting perch use and hen health. Perch material and shape
mainly affect slipperiness and grip quality and, in this regard, plastic, metal and circular perches are inferior. The incidence of bumble-
foot and keel bone deformities can be influenced by perch shape. Perch shapes which reduce localised pressure on the foot pad and
the keel-bone are recommended. Several aspects of the arrangement of the perches in the cage or non-cage system are also
important. A consistent preference for high perches is seen, provided there is a minimal distance of 19–24 cm between perch and
roof. Accessibility of high perches should be ensured, for example by incorporating lower level perches from which hens can reach the
higher levels. Such multi-height perch designs also allow behavioural differentiation according to perch height (with most passive
behaviour on the higher perches). In non-cage systems, good accessibility can be achieved by minimising the angles between perches
at different heights to smaller than 45° and by limiting the distance between horizontal perches to 1 m. The legislated minimum
perch length provided per hen (15 cm) adequately allows for synchronised roosting behaviour on straight perches. However, in cross-
wise perch designs, hens require more perch length per hen as the area close to the cross cannot be used optimally.
Keywords:animal welfare, bumblefoot, laying hen, perch design, perch use, roosting
Introduction
Perching is a natural behaviour in red jungle fowl, from
which our domestic hens originated (McBride et al 1969).
In feral conditions, domestic fowl generally roost in trees or
bushes at night. Roosting up off the ground probably has
survival value by reducing predation from night-hunting
ground predators (Keeling 2002). In modern laying hens
this perching behaviour has not been lost. Olsson and
Keeling (2000) demonstrated that hens display signs of
unrest which can be interpreted as frustration or as
increased exploration behaviour when roosting is thwarted.
Furthermore, hens are prepared to push through a weighted
push-door to gain access to a perch (Olsson & Keeling
2002). In commercial conditions, perches are provided in
both furnished cages and non-cage systems to improve the
welfare of laying hens. Gunnarsson et al (2000) and Riber
et al (2007) showed that early experience with elevated
perches during rearing improves the ability of hens to deal
with perches in complex housing systems for layers, later in
life. The provision of perches allows for the expression of
perching behaviour and perches can be used to escape from
active feather peckers or aggressive hens (Wechsler &
Huber-Eicher 1998; Cordiner & Savory 2001). Perches also
seem to have positive effects on the physical condition of
hens, for example by increasing bone strength (Hughes &
Appleby 1989). However, keel-bone deformities (Appleby
et al 1992; Abrahamsson & Tauson 1993), bumblefoot
(Tauson & Abrahamsson 1994) and bone fractures (Freire
et al 2003; Wilkins et al 2004) have also been associated
with the use of perches. Bumblefoot is a local infection of
the foot pad which causes a bulbous swelling (EFSA 2005).
The acute state usually occurs around 30–40 weeks of age
and is extremely painful. Intensive and/or long-term use of
perches and misjudged landings can lead to development of
keel-bone (sternum) deformities. The extent to which this
condition is a welfare problem is unclear, but involvement
of the pre-sternal bursa (bursitis) is considered painful
(Tauson & Abrahamson 1994; EFSA 2005).
The only requirements concerning perches in the EU-
Directive 1999/74/EC is that there has to be at least 15-cm
perch length per hen (furnished cages and non-cage
systems), that the perches, without sharp edges, must not be
mounted above the litter (non-cage systems) and that the
horizontal distance between perches must be at least 30 cm
(non-cage systems). These rather limited requirements
allow for a wide variety in perch design features (material,
width, shape, etc) which might contribute to variations in
perch use and hen health. Therefore, the objective of this
Universities Federation for Animal Welfare Science in the Service of Animal Welfare
534 Struelens and Tuyttens
study is to review the scientific literature on the effects of
altering design features of perches on the behaviour, health
and ultimately the welfare of laying hens.
Perch features affecting perch use and hen health
Perch length
Synchronism is important in roosting behaviour (Appleby
2004; Appleby et al 2004) and, as such, perch space should
be sufficient for all birds to perch simultaneously (Appleby
et al 1992). According to Directive 1999/74/EC, 15-cm
perch length per hen should be provided. Previous research
supports this recommendation (Appleby et al 1992),
although Appleby (1995) found no significant difference in
perch use at night between a perch length of 14 and 15 cm
per hen. He concluded that a perch space of 14 cm was
adequate for medium hybrid laying hens. For light hybrid
laying hens however, Tauson (1984) suggested that 12-cm
perch length per hen is sufficient.
Perch material
Currently, the most common materials for the construction
of perches in commercial systems are wood, plastic and
metal. Lambe and Scott (1998) compared rectangular
wooden, metal and plastic perches and found no difference
between the different materials in the duration of time that
hens spent perching. They also found no difference in
perching time between hard (wooden rectangular perch) and
soft (wooden perch covered with a layer of foam rubber)
perches. Appleby et al (1992) found that, although most
time was spent perching on a softwood perch, followed by
a vinyl-padded and metal perch and least of all on a plastic
perch, these differences were again not statistically signifi-
cant. It was suggested that a slightly rough surface was
preferred because softwood and vinyl-padded perches
provided most grip for the feet of the hens, whereas plastic
perches had the smoothest surface. This suggestion was
later supported by Scott and MacAngus (2004) who showed
that the behaviour of hens indicated that metal and PVC
perches were more slippery than wooden perches. They
concluded that surface modifications, such as the inclusion
of grooves, may reduce slipperiness, and hence should be
investigated further. As well as texturally, wood also has the
advantage of being cheap and easy to use. However, it has
the disadvantage of being liable to wear (hardwood has
been reported to withstand wear from the hens’ feet and
claws much better than softwood [Tauson & Abrahamsson
1994]). Moreover, it is difficult to clean and disinfect and
provides attractive hiding places for red mites
(Dermanyssus gallinae) (Lambe & Scott 1998).
Cross-section and shape
In commercial situations, it is often perches with rectan-
gular and circular cross-sections that tend to be used. Lambe
and Scott (1998) found no significant differences in
perching time between these two perch types during a 48-h
observation period. However, Duncan et al (1992) found a
trend for more perching on rectangular perches compared to
circular perches during the day, but not at night. In the latter
study, it was reported that the hens’ feet slipped backwards
and forwards during feeding from the circular perches indi-
cating that they were unstable. Both perch shape and
material (see above) seem to affect perch slipperiness.
Therefore, circular perches with a smooth surface (eg metal)
seem inappropriate with regard to stability.
Oester (1994) showed that the shape of perches had an effect
on the development of bumblefoot. Channeled perches
(rectangular perch with a groove in the middle) and double
perches (two thin parallel perches close together, acting as a
single perch) resulted in fewer bumblefoot lesions than a
rectangular (with and without a cover of rubber) perch or a
mushroom-shaped perch. Duncan et al (1992) found that
perches with a rectangular cross-section caused less damage
to the feet of birds than those with a circular cross-section.
However, Tauson and Abrahamsson (1994) reported more
bumblefoot problems with rectangular perches than with
circular perches and, according to Rönchen et al (2008),
circular perches did not appear to negatively influence foot-
pad health. Tauson and Abrahamsson (1994) also showed
that a plastic, mushroom-shaped perch caused more bumble-
foot lesions than a wooden rectangular narrow (3.5 cm), a
wooden rectangular wide (5.3 cm) and a circular perch with
flattened lower and upper surfaces. Valkonen et al (2005)
reported that foot-pad condition was poorer in cages with
plastic perches than in cages with wooden perches.
However, the shape could also have influenced the foot-pad
condition because the wooden perches were circular or
rectangular whereas the plastic perch was T-shaped. For
most of the studies mentioned above on bumblefoot lesions,
it is difficult to reach conclusions on specific perch features
since different materials were used.
Perch shape clearly affects the incidence of keel-bone defor-
mities. Circular perches caused more damage to the keel
bones of hens than rectangular perches, probably because
they imply great localised pressure to the keel bone in
roosting hens (Tauson & Abrahamsson 1994).
Perch width and size
It has been described that under natural conditions hens
clasp their feet around branches (Blokhuis 1984) and they
also do so around perches smaller than the length of the
hens’ feet in commercial situations. Wider structures
preclude gripping and the use of the digital tendon locking
mechanism (Tauson & Abrahamsson 1994). Although the
use of 4–5 cm wide perches is widespread in commercial
situations, little research has been done on hen preferences
for perch width.
Appleby et al (1998) found less perching during the day on
rectangular 3.8-cm wide perches compared to those 6-cm
wide in a first trial, but not in a second. In a preference test
offering the same perch widths, there was no difference in
time spent on the perches. Struelens et al (2009) investigated
the preference for 7 perch widths (1.5 to 10.5 cm) in two
experimental set-ups: one with two long perches gradually
broadening and narrowing stepwise and another with seven
separate short perches differing in width. During the night,
hens showed no perch width preferences. During daytime, in
both experimental designs, a narrow perch of 1.5 cm was
© 2009 Universities Federation for Animal Welfare
Effects of perch design on laying hens 535
least preferred by the laying hens. For wider perches, results
from both experiments were not univocal. Perch use
increased with increasing perch width in one experimental
set-up, but not in the other. The latter showed a preference for
4.5 cm wide perches as opposed to 1.5 cm perches.
In a large scale study on non-cage commercial farms,
Niebuhr et al (2008) found that the width of perches had a
significant effect on keel-bone alterations (deviations and
fractures). There were significantly more keel-bone alter-
ations (deviations and fractures) with decreasing perch
width (K Niebuhr personal communication 2009).
Perch height
In multi-tiered, non-cage systems, perches are found at
different heights whereas in furnished cages, perches are
often placed 6-to-8 cm above the cage floor which is suffi-
ciently high to allow floor eggs to roll to the egg collection
belt and sufficiently low to allow easy passage of hens
across the cage. However, in a recently developed cage
system, the ‘kleinvoliere’ (bigger version of a furnished
cage with among other things an increased cage height
compared with EU-standards), a minimum of two perches at
different heights are required (van Horne et al 2007).
The height at which perches are placed in the cage or pen
would appear to be an important factor in perch design as it
has been frequently observed that birds use the highest
accessible structures for perching at night. For example,
Lambe and Scott (1998) reported that hens roosted on the
drinker line and on top of the nest box which were posi-
tioned higher than the perches. Preference for the highest
perches at night has been documented for cages (Struelens
et al 2008a), floor pens (Olsson & Keeling 2000) and aviary
systems (Abrahamsson & Tauson 1995; Oden et al 2002).
Newberry et al (2001) also reported a strong preference for
the highest perch in young pullets during the day.
Non-cage systems offer more possibilities than furnished
cages for the incorporation of elevated perches or tiers. It is
not clear whether the low perches in furnished cages are
perceived as ‘true’ perches by the laying hens (EFSA 2005).
Nevertheless, they are used intensively by laying hens when
they are the only option available (Abrahamsson & Tauson
1993; Wall et al 2002). Although low perches are heavily
used by laying hens, a preference test with the choice
between perches of height 6, 11, 16, 21, 26, 31 and 36 cm,
showed that even in low cages hens preferred perches
higher than 6-to-8 cm. In 45 cm high cages, the preferred
perch height was 16–21 cm (Struelens et al 2008a).
In a cage environment and, to a lesser extent, in multi-tiered
non-cage systems, hens are restricted by height. Not only is
the distance between floor and perch crucial, the distance
from the perch to the roof is also an important factor in perch
use. Struelens et al (2008a) concluded that a distance of 19-
to-24 cm between perch and roof is necessary for most birds
to roost. Consequently, higher cages allow for higher
perches. For example, 45-cm high cages (the minimum cage
height according to EU-Directive 1999/74/EC) would allow
the opportunity for perches to be 21-cm high
(45–24 cm = 21 cm), whereas cages 55 cm-high would allow
perches to be 31-cm high (55–24 cm = 31 cm). When intro-
ducing higher perches, an important aspect is accessibility;
the restricted environment of a furnished cage, can make it
difficult for hens to jump or fly to the higher perch levels.
Therefore, stepwise perch designs should be introduced or
higher perches combined with lower levels to allow hens to
use them for access to higher perches (Struelens et al 2008a).
Such an approach would be likely to cause behavioural
differentiation according to perch height. Struelens et al
(2008a) showed that behavioural differentiation, with more
standing and walking on lower perches and more sitting and
sleeping on higher perches during the day, was clearly in
evidence in 150-cm high cages and to a lesser extent in those
at a height of 55 and 50 cm. It appeared that the higher the
cage, the more pronounced the differentiation. Behavioural
differentiation has also been reported in non-cage systems.
For example, Hansen (1994) reported that the majority of
resting behaviour of hens in two types of aviary systems was
performed on the upper levels, and Rodenburg et al (2008)
described a clear separation of active birds, in the scratching
area or on low perches, and resting or preening birds on high
perches in non-cage systems. Behavioural differentiation
according to perch height was also reported in small floor
pens by Appleby and Duncan (1989).
As well as perch use, other factors should be taken into
account in determining the optimal perch height for hen
welfare. For example, Wechsler and Huber-Eicher (1998)
demonstrated that feather damage was more severe in hens
housed with low (45 cm) versus high (70 cm) perches. The
effect of perch height on feather damage was pronounced for
the lower body parts (breast, legs, vent) in particular,
suggesting that hens in pens with low perches were exposed
to severe feather pecks when located on the perches. Indeed,
feather pecking directed at the vent was more frequent in
pens with low rather than high perches. They concluded that
perches for resting hens should be positioned well above the
reach of hens standing on the floor or on elevated platforms
in non-cage systems. Higher perches can also have an impact
on hen hygiene because perching hens can defaecate on
lower-standing birds (Moinard et al 1998). Perches also
seem to have a positive effect on bone strength. Bone
fragility or cage layer osteoporosis is a well-known
condition in laying hens that is related to several causal
factors including the level of egg production, the mineral
content of the diet and the amount of physical activity
(Webster 2004; EFSA 2005). Increased humerus and tibia
strength have been recorded by several authors in cage
systems with low (6–8 cm) perches compared to cages
without perches ( Hughes & Appleby 1989; Abrahamsson &
Tauson 1993). As well as time spent perching, the activity
(stepping on or off perches, wing movements) of the hens
appears to have an influence on bone strength (Appleby et al
1992; Tauson & Abrahamsson 1994). For example, Tauson
and Abrahamsson (1994) found a stronger humerus in the
Bareham and Elson Get-Away cages, with higher perches,
compared to furnished cages with lower perches. Scholz
et al (2008) showed that the heterophil-to-lymphocyte ratio
(long-term stress indicator) was lower in hens kept in a small
Animal Welfare 2009, 18: 533-538
536 Struelens and Tuyttens
group housing system or ‘kleinvoliere’ compared to hens
housed in furnished cages, indicating that hens in the small
group system experienced less stress. The perch heights in
the small group housing system seemed to have an effect on
hens’ stress levels because the treatment with perches of 6-
cm high (front perch) and 20-cm high (back perch) appeared
to impose less environmental stress than treatment with
perches at 27.5 (front perch) and 20 cm (back perch).
Possible explanations for this could be the more secluded
perching possibilities in the first treatment and the obstruc-
tion of easy passage in the second (Scholz et al 2008).
Arrangement
In furnished cages, one perch positioned parallel to the feed
trough is often unable to provide enough perch space per
hen in order for the legislative minimum of 15 cm
(according to the EU-Directive) to be met. Possible alterna-
tives are the incorporation of multiple parallel perches, the
construction of T-perches or the construction of cross-wise
perches, all of which are seen commercially. There are only
two published studies investigating the effect of cross-wise
perch designs on perch use. Wall and Tauson (2007) found
that although perches arranged in a cross provided more
perch space per hen (15 cm) than a straight perch (12 cm)
fitted across the cage, perch use at night was similar or
lower compared to the straight perch. Struelens et al
(2008b) studied the effect of cross-wise perch designs on
perch use during day and night and found significant effects
in both periods. They concluded that the addition of a 30-cm
perch cross-wise to another perch should not be included in
the total amount of perch length provided as it did not lead
to an increase in mean number of hens perching. Results
also indicated that in cross-wise perch designs, some parts,
close to the crossing, cannot be used by the hens, but further
studies are needed the determine the precise distance. There
were also indications that the process of taking roosting
positions was more disturbed with cross-wise perches.
Due to the high incidences of bone fractures reported in non-
cage systems (Freire et al 2003; Wilkins et al 2004) probably
as a result of accidents during movement between perches or
platforms (Gregory et al 1990), some studies focused on the
angle, distance and visibility of perches. Scott et al (1997)
and Moinard et al (2004) found that hens could move more
easily upwards than downwards. For example, Moinard et al
(2004) demonstrated that behaviours indicating inaccurate
landing control (long time to achieve balance, clumsy or
missed landings) were more frequent on downward than
upward jumps. Scott et al (1997) found that angles greater
than 45° between perches at different heights were difficult
for birds to negotiate. Moreover Lambe et al (1997) showed
that frustrated behaviour was associated with descending
perches separated by more than 45°. Scott and Parker (1994)
studied the effect of increasing distances between perches at
the same height on hens’ behaviour and showed that hens
cannot readily move between horizontal perches greater than
1 m apart. Scott et al (1999) found a considerable number of
unsuccessful landings when the distance between perches
was 1.5 m. Moinard et al (2005) showed that hens were often
able to jump from or into a 15-cm space between obstruc-
tions, but that this required changes in take-off and landing
behaviour. For example, to avoid an obstructing hen directly
ahead, hens would prefer to walk along the take-off perch
and then take-off on a path perpendicular to the landing
perch thereby avoiding a diagonal path when jumping.
Besides perch arrangement affecting the movement of hens
through the housing system, rearing conditions can also have
an effect. For example, Gunnarsson et al (2000) concluded
that rearing without perches during the first 8 weeks of life,
impairs hens’ spatial cognitive skills.
The effect of light intensity (usually maintained between
5 and 10 lux in commercial systems [Appleby et al 1992]),
on landing accuracy was investigated by Moinard et al
(2004). They found no significant effect of lighting
condition (5, 10 or 20 lux) on take-off, flight and landing
behaviours. These behaviours were also unaffected by the
level of contrast between the perch and background. In
contrast, Taylor et al (2003) demonstrated that at very low
light intensities hens took longer to jump, were less likely to
jump and showed a high frequency of vocalisation when
required to jump from a start perch to a destination perch.
The effects of light intensity (0.8, 1.5, 6.0 or 40 lux) on the
ability of hens to jump between perches in this experiment
was only seen at relatively low light intensities, indicating
that in commercial systems it is unlikely this would affect
the movement of hens during the light period. However,
very low light intensities can restrict the movement of hens
during dawn or dusk periods or during the lights-off period.
Taylor et al (2003) showed that altering perch colour (light
colour) could solve this problem.
Conclusion and animal welfare implications
The objective of this study was to review the scientific liter-
ature concerning the effects of altering perch design
features on the behaviour, health and ultimately the welfare
of laying hens. A firm grip of hens’ feet onto perches
appears highly significant and it seems that perch material
and cross-section contribute to this. Slipperiness is
increased with PVC and metal perches and circular perches.
The shape of the perch seems mainly to influence inci-
dences of keel-bone deformity and, albeit less clearly,
bumblefoot. In general, in order to reduce the incidence of
these disorders, perch shapes that reduce the localised
pressure on the keel bone and distal foot pad, respectively,
are recommended. Perch height is an important factor in
perch use. Therefore, perches should be positioned at as
great a height as possible and at different levels to
encourage behavioural differentiation. In determining the
optimal height, the distance between perches and the roof,
perch accessibility, the potential for feather pecking and the
ease of passage should all be taken into account. It seems
that not all laying hens are able to perch simultaneously in
cage systems with cross-wise perches that provide 15-cm
perch length per hen. Therefore, in these designs, the
minimum perch length per hen should be increased or
cross-wise perch designs should be prohibited. To minimise
the risk of injury, the angle between perches at different
heights should be no greater than 45° and the distance
between horizontal perches should be no more than 1 m.
© 2009 Universities Federation for Animal Welfare
Effects of perch design on laying hens 537
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© 2009 Universities Federation for Animal Welfare
... Consistent with the anti-predator strategy, laying hens prefer a high perch (60 cm above the ground) over a lower perch (15 cm) (Schrader and Müller, 2009). Regarding materials, laying hens do not show much preference for particular features such as material or width (Liu et al., 2018), but have in some studies shown a preference for flat and wide perches (<4 cm) (Struelens and Tuyttens, 2009;Pickel et al., 2010;Skånberg et al., 2021). Perches of hard materials such as steel or hard plastic are durable and hygienic, and could be a good option if the birds do not show preferences between materials. ...
Article
An important behavioral need for laying hens is perching, but few studies have investigated perching behaviour in commercial broiler breeder pullets. The aim of this study was to investigate perching behaviour throughout the pullet period and preferences for different perch types and heights. We also investigated the effect of hybrid on perching and the potential effect of perches on keel bone damage (KBD) and footpad dermatitis (FPD). We followed four commercial broiler breeder pullet hen flocks (Ross 308, n=2 and Hubbard JA 757, n=2), each with three groups of birds (n=2 500 hens); A-group; four A frames consisting of four perch types (plastic, steel square, steel round and wood) placed on different heights (35 cm and 95 cm); S-group; Siesta perches (a plastic perch 15 cm high) and C-group; control group without perches. Perch use was recorded by counting number of birds on the perches during the last hour before the light went off, at week 2, 5, 6, 7, 10, 12 and 15. At week 16, footpad dermatitis, keel bone deformations and keel bone fractures were scored in 30 random birds in each group (n= 90 birds/flock). Hubbard birds perched significantly more than Ross birds (P < 0.0001), and more birds perched on the Siesta perches than on the A frames (P = 0.046). Perching increased with age for Hubbard birds (P < 0.05), but not for the Ross birds. There were no effects of perch height or perch types on number of birds observed on the perches. There were no observed cases of bumblefoot, breast blisters, keel bone deformations or keel bone fractures. The incidence of FPD was low, with 73.6% of assessed birds receiving a score of 0, with no significant differences between hybrids or perch groups. In conclusion, Hubbard birds perched more than Ross 308 birds, and all birds perched more with age. None of the hybrids showed any preferences for perch type or height and increased perching had no negative effects on important health parameters. Broiler breeder pullets should therefore be given access to perches from day 1 to promote training and perch use.
... Enriched cages have reduced hyperkeratosis of the toe pads associated with sloping wire floors in conventional cages, but perches (in any system) can cause greater incidences of bumblefoot (Abrahamsson and Tauson, 1993) although this can be altered with perch design (for reviews of designs, see Sandilands et al., 2009;Tuyttens, 2009). Claw shorteners have been successful at reducing long and broken claws commonly seen in conventional cages, providing they are suitably positioned and are replaced when worn. ...
... Several studies have evaluated perch materials and found that different perch materials may have an impact on keel bone deformities in commercial laying hens (Kappeli et al., 2011;Stratmann et al., 2015). Several studies have also examined the effect of different perch shape on keel bone deformities and found differences between various shapes (Struelens and Tuyttens, 2009;Pickel et al., 2011). However, no differences between our 2 caging systems were reported with respect to the prevalence of keel bone damage. ...
Article
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Damage to the keel bone is a major issue in the laying hen industry. The goal of this study was to compare palpation results of live laying hens to digital computed tomography (CT) images, to assess changes in palpation reliability as training and familiarity increased, and to examine keel bone morphology over time. The longitudinal study consisted of 2 trials of 3 observation periods using 40 different (n = 120) W-36 hens housed in enriched colony cages. The first trial began when hens were 52 to 58 wk of age repeating the trial when the same birds were 74 to 81 wk of age. At 52 wk of age, each hen's keel bone was palpated by a single individual for keel bone caudal tip fractures (Tip), sagittal deviations (Evenness), and transverse deviations (Straightness). After palpation, each hen was placed in a motion limiting restraint and scanned using CT. The hens spent the next 21 d in their cages and on day 21, the hens were collected, palpated, and CT scanned again. The CT scans were imported into Mimics analysis software, 3D models of each keel bone were constructed and evaluated. Each bone and 3D model was scored (0, 1, 2) on the measurement of transverse deviation based on <0.5 cm, 0.51 to 1.0 cm, and >1.0 cm total deviation, respectively. Analysis of data using Proc Freq and Means in SAS 9.3 revealed minimal to moderate kappa values and moderate agreement percentages between palpators and digital analysis. The computer generated 3D models of individual keel bones were compared to palpation scores for Tip, Evenness, and Straightness at the beginning and end of each trial. The visual observations of the 3D models were qualitative, performed by a single individual. Overall, we found CT scanning to be a useful tool in observing changes to the keel bone, we observed changes in palpation accuracy as training/familiarity increased, and examined changes in keel morphology, specifically in the tip, after 52 wk of age.
... Recent studies indicate that access to perches ( Hester et al., 2013) and a slow lighting program ( Hester et al., 2011) during the pullet phase are promising factors to improve bone integrity during the laying cycle. Several researchers have shown that perch material, diameter, and shapes of perches also can influence keel integrity of the laying hen ( Tauson and Abrahamsson 1994;Struelens and Tuyttens, 2009;Stratmann et al., 2015); however, it is important to note that these factors have not been evaluated during the pullet phase. An elevated Ca: P ratio in pullet and pre-lay diets increased femur breaking strength at the end of the layer phase without affecting pullet BW gain or pullet feed efficiency in cage systems ( Fosnaught, 2009). ...
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This study was conducted to evaluate limestone particle size (LPS) in 2 strains of laying hens housed in conventional cages or aviaries on bone integrity. Lohmann Brown and Bovan White pullet chicks were started in equal numbers on the floor or in battery brooders and were intermingled throughout all subsequent housing systems. At 5 wk of age, 432 floor-raised pullets were moved to 8 aviary cages. At 10 wk, 256 battery-raised pullets were transferred to 64 conventional layer cages. Pullets were given diets containing fine (LPS-FINE, 0.431 mm) or a blend of fine and coarse (LPS-BLEND, 0.879 mm) LPS from 7 to 17 weeks. Data were analyzed as a split plot factorial design with strain as subplot and with 4 replicates for each treatment combination. Body weight, feed intake, egg production, and eggshell breaking strength and percentage were measured. Tibia bone mineral density (BMD) was determined using a dual energy x-ray absorptiometry. Presence of keel indentations, curvatures, or fractures was recorded. LPS-BLEND increased BMD (0.215 vs. 0.208, P = 0.03) at 18 weeks. During the pullet phase, the odds of pullets fed LPS-FINE displaying keel curvatures were 2.8 times the odds of those fed LPS-BLEND (P = 0.04). At 54 wk, hens fed LPS-BLEND as pullets had lower odds of keel indentations (P = 0.02). Brown aviary hens fed LPS-BLEND as pullets had the lowest egg production compared to the rest of the treatment combinations (P = 0.004). Taken together, feeding LPS-BLEND to pullets improved bone mineralization at the onset of sexual maturity and reduced keel damage during the pullet and layer phases, regardless of strain; however, LPS-BLEND was associated with lower egg production in Brown hens housed in aviaries compared to all others.
Article
Unlike for laying hens in most European countries, few broiler breeders have access to perches, and there is a need for more knowledge on perching behaviour in broiler breeders. The aim of this study was to investigate the overall use of perches by broiler breeders throughout the production period and to investigate preferences for different perch materials in a commercial setting. Four breeder flocks (Ross 308, n=2, Ranger Gold, n=1, Hubbard JA 757, n=1) were each given five different perches. Four of the perches (each 6 m long) were placed on the elevated slats; steel round, steel square, plastic and wooden perch, while the three Siesta perches (plastic, 15 cm high) were placed in the litter area. From week 30, one of the Siesta perches (3 m long) was placed on the elevated slats. Perch use was recorded by counting number of birds on the perches during the last hour before the light went off, once in week 20, 25, 30, 40, 45 and 50. Footpad dermatitis were scored at end of lay in 100 random hens across the house. Overall, perching behaviour was constant with age, and there were no significant differences between the flocks with regards to perch use (birds/m perch). At 20 weeks of age, the square steel perches were most used (0.90 birds/m perch) and the wooden perches were the least used (0.41 birds/m perch) (P=0.09). From week 30, more birds were perching on the Siesta perches on the slats (1.6 birds/m perch) compared to all other types of perches (P < 0.003). There was no relationship between body weight and footpad score (P > 0.05). The average perch use in the present study was only 0.44 birds/m perch which is a capacity utilization of less than 10%. The Siesta perch on the elevated slats was the most popular perch, possibly due to its height. In conclusion, broiler breeders use perches, but perch type and placement of the perches must be considered carefully.
Article
Beach-nesting shorebirds are declining due, in part, to human disturbance in nesting areas. Sign-posts are installed around nesting areas to protect nests from people, but they may serve as perches and attract avian predators. From March–August 2018, we used passive infrared game cameras to monitor perching activity on 15 variations of sign-post designs on 2 barrier islands in North Carolina. We observed 110 independent perching events dominated (70%) by common (Quiscalus quiscula) and boat-tailed grackles (Quiscalus major) and laughing gulls (25%; Leucophaeus atricilla). We compared how the number of days perching occurred was associated with sign shape, material, sign-construction (sign x shape), position on post, and presence/absence of a nail on top of the post. Position of the sign on the post had the strongest effect on the number of days perching events occurred (χ² = 18.62 df = 2 P < 0.001). Signs positioned flush with the top of the post were most frequently perched on (10% of perching days), followed by signs positioned lower (5%) and higher (2%) than the post top. The frequency of avian predators perching on triangular signs (8%) and rectangular signs (5%) did not differ (X2 = 2.89 df = 1 P = 0.11). While sign material (metal: 12%; laminated cardboard: 11%; plastic: 13%) did not affect the probability of perching (χ² = 1.06 df = 2 P = 0.58), triangular plastic signs (11%) had more (χ² = 6.011 df = 2 P = 0.05) perching activity than rectangle-metal (6%) and rectangle-laminated signs (6%). Presence (3%) or absence (4%) of a nail on top of posts did not affect the number of days perching occurred on a sign-post (χ² = 0.59 df = 1 P = 0.52). We recommend managers position signs high on the post to reduce occurrences of predatory perching. If a choice of sign shape and material is available, rectangular metal or laminated cardboard signs may also reduce perching activity.
Article
In response to consumer demands and legislative measures for improving hens' welfare, many laying hen producers are replacing conventional cages with aviaries. Aviary resources, such as nest boxes, litter areas, ledges, and perches, are intended to increase the display of natural behaviors. However, commercial laying hen strains have been differentially selected for varying traits including egg quality, feed efficiency, and behavior. Therefore, the assumption that laying hens are using the given resources similarly, irrespective of their genetic strain, may be false. This research examined the influence of laying hen strains (brown hens: Hy-Line Brown, Bovans Brown; white hens: DeKalb White and Hy-Line W36) on resource or flooring substrate occupancy (litter areas, nests, elevated wire tiers, ledges, and perches) inside aviaries during peak lay (25 to 28 weeks of age), and whether this occupancy changed in response to litter access. Live observation and video-recording of hens' distribution among different resources were conducted at 3 different times (morning, midday, and evening) for 3 consecutive days, immediately before (PRE), immediately after (IMM), and 3 weeks after (ACC) hens gained access to litter. Observations were conducted in 16 aviary units; 4 units/strain, 144 hens/unit. Data were analyzed in R using generalized linear mixed model with Tukey's post hoc test and α set at 0.05. More brown hens were in nests than white hens during morning across all periods (PRE; P = 0.002, IMM; P = 0.012, and ACC; P = 0.015), but more white hens were recorded in nests than brown hens during midday of all periods (PRE; P = 0.026, IMM; P = 0.028, and ACC; P = 0.024). More white hens were on litter compared with brown (P = 0.002), particularly when litter was first accessible. White hens occupied the open litter area in larger numbers than brown hens during midday and evening of IMM and ACC periods (P ≤ 0.05). Brown hens occupied the underneath litter area in larger numbers than white hens during midday and evening of the ACC period (P ≤ 0.05). Throughout the day, brown hens occupied wire floors in higher numbers than white hens, whereas the latter occupied both ledges and perches more (all P ≤ 0.05). These strain differences suggest that specific aviary designs may be best suited to specific hen strains.
Article
Provision of perches in enriched colony or cage-free hen housing facilitates birds' ability to express natural behaviors, thus enhancing animal welfare. Although considerable research has been conducted on poultry perches, further investigation is needed of perching behavior and preference of laying hens to perch exposure and perch types. This study aimed to assess preference of young laying hens for round vs. hexagon perches and to characterize temporal perching behaviors of the young hens brought to an enriched colony setting from a cage pullet-rearing environment. A total of 42 Lohmann white hens in six equal groups, 17 weeks of age at the onset of the experiment, were used in the study. Each group of hens was housed in a wire-mesh floor pen equipped with two 120 cm long perches (one round perch at 3.2 cm dia. and one hexagon perch at 3.1 cm circumscribed dia., placed 40 cm apart and 30 cm above the floor). Each group was monitored continuously for 9 weeks. Perching behaviors during the monitoring period, including perching time, perch visit, and perching bird number, were recorded and analyzed daily using an automated perching monitoring system. Results revealed that the laying hens showed no preference between the round and hexagon perches (P = 0.59-0.98). Young laying hens without prior perching experience showed increasing use of perches over time (P < 0.01). It took up to five to seven weeks of perch exposure for young hens to show consistent perching behaviors in the enriched colony setting. This study also found that laying hens spent about 10% of daytime on the perches and over 75% of hens perched at night after approaching consistent perching behaviors. In general, the results supplemented to the existing knowledge base for the quantitative behavior study on laying hens' temporal perch use.
Article
Full-text available
SUMMARY In 2 trials, including 2,768 birds in total, 3 different perch arrangements were evaluated in furnished 8-hen cages for laying hens. The hybrids used were Lohmann Selected Leghorn and Lohmann Brown in trial 1 and Hy-Line White and Hy-Line Brown in trial 2. The furnished cages were identical in all other respects than the arrangement of perches. A perch was either fitted across the cage, providing 12 cm of perch per hen, or 2 perches were installed in a cross, implying 15 cm per hen. Although the perches arranged in a cross provided more perch per hen than the single perch fitted across the cage, perch use at night by the birds was similar or lower as compared with the single perch. Hence, the way perches are arranged in the cage may be as important as perch length itself to achieve a high use at night. Perch arrangement did not affect production, mortality, or egg quality. Compared with a conventional battery cage, also included in the trials, hygiene was inferior in the furnished cages, but there was no difference in proportions of dirty eggs. Differences in proportions of cracked eggs were found between furnished and conventional cages in 1 of the trials. However, on the whole, production, mortality, and egg quality were at similar levels in all cage models. Genotype differences were found in production traits, egg quality, hygiene, and in the use of perches and nests.
Article
Foot pad health in Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) laying hens kept in a modified small group housing system (Eurovent (EV) 625a-EU (MSG), four perches) equipped with perches at different levels, a modified furnished cage system (EV 625A-EU (MFC), two perches) with the back or the front perch being elevated, a small group housing system (EV 625a-EU (SG), four non-elevated perches), and furnished cages with (two) non-elevated perches (EV 625A-EU (FC), Aviplus (AP)), was evaluated in two trials. The occurrence of hyperkeratosis and epithelial lesions was macroscopically assessed in 576 laying hens (432 LSL, 144 LB) and classified due to the severity of alterations. In the first trial, 69 samples of sole pads and 68 toe pad samples were examined histologically. Mild hyperkeratosis was the most frequent macroscopic finding and epithelial lesions were observed in hens of all housing systems evaluated. Modified perch positions had a positive influence on some traits of foot pad health. Histological examinations revealed hyperkeratosis in sole and toe pad samples in all cases. Mild hyperkeratosis was the predominant finding in sole pads, whereas in toe pads, moderate hyperkeratosis was prevailing. Severe cases of hyperkeratosis could be observed in FC, MFC, SG and MSG. Erpsions and ulcerations were found in sole pad samples of hens kept in SG and MSG. Perivascular infiltration of lymphocytes was observed in nearly all sole and toe pad samples examined.
Article
The objective of the present study was to assess the level of stress imposed on Lohmann Silver laying hens kept in a small group housing system with elevated perches (Eurovent (EV) 625a-EU, group sizes 40, 60 hens, four perches with two different heights) compared to furnished cages (Aviplus, group sizes 10, 20, 30 hens) and an aviary housing system with a winter garden (Natura, two pens, 1,250 hens) under identical management and feeding conditions. Each two perches within compartments of EV were either incorporated in a stepped position (ST, front and back perches heightened) or with only the back perches being elevated (BE). In the 3rd, 6th, 9th and 12th laying month, approximately 36 hens were randomly chosen from each housing system (430 hens in total) and heterophil to lymphocyte (H/L) ratio was determined. Laying hens kept in EV had significantly lower H/L-ratio compared to hens housed in Aviplus (P < 0.05), whereas no difference was detected between EV and aviary system. Hens kept in groups of 40 layers in compartments with perches in the BE position showed significantly lower H/L-ratios compared to hens kept in groups of 10, 20, 30 layers (Aviplus) and groups of 40 and 60 hens with perches incorporated in the ST position. Hens kept in furnished cages reflected the greatest stress exposure. Group sizes of 40 hens together with elevated back perches were associated with lowest levels of H/L-ratios and these ratios were even lower than in hens kept in the aviary system. Differences between group size 40 (BE) and the aviary system nearly achieved the significance level (P = 0.054). Keeping hens in groups of 40 layers together with perches incorporated in the BE position indicated to be most favourable in terms of imposing the least environmental stress on layers.
Article
1. The effects of age at sexual maturity, age at culling, and stunning frequency and current on the incidence of broken bones were examined in end‐of‐lay hens. In addition comparisons were made between 4 different egg‐laying breeds, and between battery, perchery and free range husbandry systems.2. High frequency stunning (1500 Hz) caused a reduction in the incidence of broken bones compared with 50 Hz.3. Battery birds had a higher incidence of recently broken bones in comparison with perchery and free range birds. However, there were more old breaks in the perchery and free range systems than in the battery system.4. Breed of bird, age at sexual maturity and age at culling had no effect on the incidence of broken bones.
Article
1. ISA Brown hens were caged in groups of 4 from 20 to 72 weeks at 675 cm/bird. A control treatment in conventional cages was compared with 4 treatments involving softwood perches. In deep cages they were located across the front, across the rear and across both; in wide, shallow cages there was one long perch across the front. For half of each treatment perches were circular in cross section, and for half they were rectangular.2. Time spent overall in daytime perching was relatively consistent over the laying cycle, from 47% in period 1 to 41% in period 10. Perch arrangement had a major influence on perching time, which varied from 20% on the rear perch to 85% on the long perch. Predominant activities on front perches were feeding and drinking; on rear perches, preening and resting.3. Perches were heavily used for roosting at night: the proportion varied from 60 to 72% on front or rear perches, through 72 to 78% on long perches, and 99% on two perches.4. Physical condition was also affected by treatment. Foot damage was less in birds with rectangular perches than with circular perches; rear perches resulted in less damage than the control. Tibia breaking strength was greater in birds from cages with perches. There was some evidence of reduced feather damage, especially where there was sufficient perching space for all birds.5. Egg production on a hen‐d basis across 12 laying periods was 83% in cages with perches compared to 85% in control cages, with no significant differences between treatments. Hens were seen to lay from perches; this probably accounted for the higher proportion of cracked eggs from cages with perches. This proportion varied from 4% with rear perches to 18% with two perches, compared to 2% in control cages.6. Although not all effects of perches were beneficial, overall they made an appreciable contribution to bird welfare. They should be considered in combination with other potential modifications to cages.
Article
In four experiments a total of 3660 SCWL laying hens kept in conventional cages at low and high stocking densities with and without a perch, Get-away (GA) cages and aviaries with litter (AL), were used for studies on the presence of bumble foot (BF), distal toe pad hyperkeratosis (TPH), keel bone lesions (KBL) and of the breaking strength of tibia and humerus. Commercial hybrids were used: LSL (Expts. 1, 2 and 4); LSL and Shaver (Expt. 3). Only clearly observed in systems with perches, the incidence of BF and KBL was mostly affected by perch design, while BF was also strongly affected by strain and housing system. LSL showed significantly higher incidence of BF, especially in GA and AL. TPH, only found in conventional cages, was affected both by strain and stocking density, LSL hens and lower stocking density showing significantly lower incidence. Apart from welded wire net platforms, a European beech hardwood circular prototype perch with a flattened upper and lower surface seemed to combine in the best way until now low incidences of BF and KBL. Bone breaking strength was positively influenced by lower stocking density and the presence of a roost.
Article
Previous work has shown that the tendency to feather peck in domestic fowl is influenced by experiences early in life; it was hypothesised that broody hens prevent development of feather pecking and cannibalism in their chicks by increasing their ground pecking activity and by motivating them to earlier perch use.Twelve groups of 10 layer hen chicks (Lohmann Tradition) were reared in pens (2.55m2) with perches at heights of 20 and 40cm; six groups were reared with broody hens and six with heating lamps. The hens and the heating lamps were removed when the chicks were 5 weeks old. A 13-day long stress period (i.e. increased light intensity, short-term feed deprivation) was introduced when the chickens were 25 weeks old, after which the experiment was terminated.The number of ground pecks performed during 2min was recorded for all individuals, when they were 1, 8, and 20 weeks old. The position of each chick (floor, low perch, or high perch) was recorded using scan sampling 12 times a day on days 5–40. Feather pecking was recorded continuously for 30min in each group when the chicks were 5, 10, 13, 17, 20, 24, and 27 weeks old. Data were analysed using repeated measures ANOVA.The brooded chicks ground pecked four times more in weeks 1 and 8 than the non-brooded chicks, whereas the amount was similar in week 20. The brooded chicks were on average 9.8 (±0.6) days old when first observed on the low perch during day time and the non-brooded were 13.5 (±0.8) days old. No difference was found between the two treatments in onset of night perching (low perch: brooded 19.2 (±1.6) and non-brooded 22.5 (±1.9) days old). Severe feather pecking was almost non-existent in both treatments throughout the experiment, although a rise in frequency was found in the non-brooded pens in weeks 20 and 24. Mortality due to feather pecking and cannibalism was found to be significantly higher for the non-brooded chickens.In conclusion, the provision of broody hens resulted in chickens having a higher ground pecking activity, an earlier day-use of perches, and a lower mortality. Because severe feather pecking only developed to a minor non-significant extent in the non-brooded chickens, no conclusion could be made on the effect of broody hens on chickens’ feather pecking activity.
Article
Laying hens housed in extensive systems may be at risk of injury when many birds compete for use of the same perch space. Experiments were carried out to determine the space required by laying hens to move between obstructed perches. Eighty Lohmann Brown layer hens were reared in floor pens fitted with perches from 1 day of age. After the peak of lay (25 weeks of age), their ability to jump to and from perches obstructed either by inanimate objects or by live hens was assessed in four experiments. Digital video techniques were used to make detailed measurements of take-off, flight and landing behaviours.In Experiment 1, birds jumped upward or downward at a 14° angle between two perches that were separated by a horizontal gap of 80cm. Two inanimate obstructions were placed on either the take-off or the landing perch, with a space between them of 15cm (the minimum perch space required under European directive 1999/74/EC), 22.5 or 30cm. Experiment 2 was similar but included a condition in which obstructions were placed on both the take-off and landing perches. Experiment 3 compared the effect of obstructing the landing perch with hens or with inanimate objects. Experiment 4 tested the effect of placing a single hen on the landing perch, directly in front of the test bird, on its detour behaviour.With a 15cm space between obstructions, hens made significantly more successful jumps when the obstructions were on the take-off perch than when on the landing perch (P
Article
Eighty Lohmann Brown layer hens were reared in floor pens fitted with perches from 1 day of age. After the peak of lay (25 weeks of age), their ability to jump to and from perches in different light environments was assessed in two experiments using digital video techniques that allowed detailed measurements of take-off, flight and landing behaviours.In Experiment 1, birds jumped up or down (angles of 10 and 18°) between two horizontal perches that were separated by a gap of 60cm under different lighting conditions (5, 10 or 20lux; incandescent or high- or low-frequency fluorescent). In Experiment 2, the horizontal distance was increased to 80cm and contrast between perch and background was varied. Fifty-two hens (65%) achieved the training criterion for Experiment 1: jumping a 60cm gap five times of which three in a row. Thirty-two of these hens (62%) subsequently failed to achieve the 80cm jump criterion for Experiment 2.In Experiment 1, birds took off sooner (P