Survey of laying hen husbandry in
Switzerland
M. HANE, B. HUBER-EICHER and E. FROHLICH
Federal Veterinary Office, Centre for Proper Housing of Poultry andRabbits, Burgerweg 22, CH 3052 Zollikofen, Switzerland
In Switzerland eggs have not been produced in battery cages since January
1992. During the 10 year period from 1981 farmers replaced their battery cageswith deep litter, aviary and grid-floor systems and modified cages. However,the cages used to replace the conventional battery cages and most of the gridfloor systems did not fulfil the requirements of the Swiss Welfare Act and they
were not permitted to be advertised or sold thereafter. Sixteen years after theban on battery cages, the Federal Veterinary Office has undertaken a survey todetermine how laying hens are kept in Switzerland and how the alternative
systems have fared. The survey was carried out on 96 randomly chosen farms
with at least 500 hen places to find out more about the housing conditions,management processes, status and performance of hens. The results show thataviaries are very common in Switzerland (65% of the laying hens) and that thelaying performance in these systems is significantly higher than that in gridfloor systems and similar to that in battery cages. Provision of a protected
outdoor area is a valuable benefit. To be successful with aviary systems it isnecessary for pullets to spend the rearing period under similar housing
conditions.

Keywords: Poultry; layers; alternative system; management; aviary system;
Switzerland; free range

Introduction
In Switzerland eggs have not been produced in battery cages since January 1992.
The Animal Welfare Act, which came into force in 1981, was the basis for theconsiderable changes to requirements for housing conditions of laying hens. The
Animal Welfare Regulations stipulated a minimum floor area of 800 cm2 or more
per bird (depending on the quality of the floor and of the group size), protected
and darkened nest boxes and perches for all hens or, as a substitute, a suitably
slatted floor which allows the hen to close its claws normally. Since 1981 a large
variety of housing systems have been developed as alternatives to battery cages.
Because Article 5 of the Animal Welfare Act states that housing systems for farm
0 Worlds Poultry Science Association 2000

World’s Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
animals have to be tested from the welfare point of view, more than 50 alternative
housing systems were registered for examination by the Federal Veterinary Office(for more information on the examination procedure see also Frohlich and Oester,
1988; Steiger, 1988; Wechsler et al., 1997).
Investigations have shown that systems which tried to improve on battery
cages, such as ’enriched cages’ or ’colony cages’, did not fulfil the requirements of
the Welfare Act (Federal Veterinary Office, 1987).Although the space per bird wasincreased and additional equipment was installed, separate areas for feeding,
exercise, resting, egg laying and normal behaviour (e.g. preening or dustbathing)were not provided. There was also no space for birds to retreat if they were
frightened or if subordinate birds wanted to escape from dominant ones. The lackof stimuli in the hen’s environment was evident and panicking, feather pecking
and cannibalism were major problems. In order to minimise these problems thelight intensity had to be reduced drastically and it was not feasible to run thecages with light intensities of 51ux or more as required by the Animal Welfare
Regulations. Additionally, behavioural problems such as pre-laying pacing andpseudo-dustbathing were observed and the proportion of dirty eggs was high
(6-17%). In summary, the investigation revealed that the modified battery cages
did not meet the Animal Welfare Regulations and consequently they were notauthorised by the Federal Veterinary Office (1993a). Similar problems wereobserved with grid-floor systems (Federal Veterinary Office, 199313) and many ofthese did not get authorisation either.
In contrast, aviary systems, i.e. multi-level systems with litter on the floor andmanure removal on two or more levels, proved to be a favourable alternative tobattery cages (Oester and Frohlich, 1986; Federal Veterinary Office, 1995) andgained acceptance by poultry farmers. These aviaries also proved to beeconomically competitive with battery cages. With the provision of tiers andperches at different heights the hens are able to use additional space and it ispossible to separate areas for different behavioural functions. With the added
possibilities of providing access to a littered and sheltered outdoor area (‘badweather run’ or ’winter garden’) and/or a free range area, the birds are able toperform a normal range of behavioural patterns (Swiss Society for the Protectionof Animals (STS), 1994; Bessei and Damme, 1998). In aviary systems fewer
abnormal and more comfort behaviours may be observed, while productivity
remains comparable to battery farming (Tanaka and Hurnik, 1992; Blokhuis andMetz, 1995).
As well as a basic knowledge of egg production, however, more skills andexperience are needed to run aviary systems successfully. Additional knowledgeof behaviour (e.g. feather pecking), nutrition and animal health is essential(Frohlich and Oester, 1988; Bessei and Damme, 1998). In aviary systems thewelfare of the hens is more susceptible to inadequate supervision and poor
management (Appleby and Hughes, 1991).Drawbacks include floor eggs, a highconcentration of dust, harmful feather pecking and cannibalism (Blokhuis andMetz, 1995; van Horne, 1996).
In 1997, six years after the last battery cage had been removed, the Federal
Veterinary Office wanted to find out more about how laying hens are kept in
Switzerland. It commissioned a representative survey aimed at determining
housing conditions, management and the health of the hens. The study included
all farms with at least 500 places for laying hens, i.e. 742 farms according to theFederal Statistical Office (1995). These farms supply about 75% of all eggs
produced in Switzerland.

22

World’s Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane e f al

Methods
In March 1997 the 742 farms were invited to join the survey. In order to obtain arepresentative sample the letter of invitation was formulated in as neutral amanner as possible. Within two months, 41 % of the farms had replied and 85% ofthem (256farms) agreed to participate. Of these, 105 farms were chosen at random
to be included in the study. Between October 1997 and April 1998,96 of them werevisited; the remaining nine were not visited either because they did not have hensat that time or because they had lost interest in the survey. The length of thespecially developed questionnaire and the complexity of the topic required apersonal visit rather than simply mailing the questionnaire to the farmer. The
survey sheet was filled in during an inspection of the hen houses and theirenvironment, and with the help of an interview with the farmer. As a point ofreference for information on the management, health and performance of thebirds, the eldest flock on the farm and the preceding one were used. Additionally,
a pooled sample of excreta (about 20 droppings) was taken from the examinedflocks and sent to an accredited laboratory for examination of endoparasites. In
the laboratory a suspension of zinc chloride was used (Boch and Supperer, 1992)
to detect coccidial oocysts or eggs of worms. The time of the farm visits ranged
from 1.5 to 3 hours. To ensure consistent quality of data, all the visits were carriedout by the same person.
Because the ages of the examined flocks differed (mean (SD) 59.1 (20.8)weeks),
the data concerning performance were not directly comparable. The value of
performance is therefore given as the positive or negative difference (in percent)compared with the value on a standard laying curve (eggs per hen-day) for thecorresponding age of the flock. This curve is based on an evaluation carried out
by the Association of Swiss Poultry Farmers VSGH (1998a)on the performancesof 900 commercial flocks. At 72 weeks of age the VSGH standard curve shows
296.3eggs per hen. This is 4.4% less than the average performance of caged laying
hens in German institutions for breeding selection (Petersen, 1998).
The mortality among the flocks (minimum age 28 weeks) was compared by
calculating the average rate per 28 days. The analysis of the data shows nocorrelation ( u = 0.004)between the age of the flock and the mortality rate. Data
relating performance and mortality could not be collected from all flocks because
farmers did not always keep accurate records.
The condition of the plumage was recorded by scoring the appearance of the
majority of the hens in a flock. The plumage was scored for damage at fivedifferent areas of the body (head/neck, pectoral tract, tail/back, wings, cloaca/
abdominal tract) using a four-point scale where 1 = feathers intact, 2 = feathers
bristly and abraded, 3 = nude spots <5cm in diameter and 4 = nude spots> 5 cm in diameter. For the analysis a plumage index (range 5-20) was calculated
by adding up the scores from the five body areas.
Generally, means and standard deviations (SDs) were used to describe central
tendencies and variabilities of data, and parametric statistics were used to analyse
them. In some cases median values with 10% and 90% percentiles are given fordata with skewed distributions.

Results
STRUCTURE OF FARMS

In Switzerland the value of production of shelled eggs and egg products
amounts to roughly 200 million Swiss francs, a sum which represents 3.6% of theWorld’s Poultry Science Journal, Vol. 56, March 2000

23

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
total animal production in 1997 (Schweizerischer Bauernverband, 1998). In
addition to selling eggs, most farmers have other sources of income; 79% of themestimate that they obtain no more than 50% of their income from the sale ofeggs.
The mean (SD) number of birds per farm is 3042 (3600). Today, 59.3% of theflocks (53.3% of all laying hens) have access to outdoors. In addition, many ofthem (48.9%of the flocks, 43.6% of the hens) have access to a bad weather run anda free range area. Farms where only a free range area is provided with noassociated bad weather runs (4.4% of the flocks, 2.6% of the hens) or a bad
weather run without a free range area (6.0% of the flocks, 7.1% of the hens) are notvery common.
HOUSING CONDITIONS

Housing systems and equipment. Aviaries are very common in Switzerlandwith 65.2% of all laying hens (48.9%of all flocks) being kept in such systems (Table1). The four most successful models are Rihs Boleg I1 (29.2%),Voletage (24.7%),
Natura 3-tiers (18.0%)and Natura 2-tiers (14.670).Most large flocks are kept inaviary systems whereas deep litter systems (34.1%of the flocks) are preferred forsmaller flocks.
Almost all hens (99.1%)are kept in housing systems with access to litter within
the hen house (Table 1).In 8670 of all hen houses the litter area amounts to at least
20% of the total surface area available to the birds. In this study surfaces weredeemed to be available to the birds if there was a height of at least 45cm above
them, if they were at least 30 cm wide, and if the slope did not exceed 12%.Straw
is usually used as litter (69%),either alone or in combination with other materials,
but wood shavings are also popular (36%).Only 14% of hen houses provide morethan 3 cm of litter at the start of the laying period, but after 2-3 months this rises
to 8390.In 21% of the hen houses the maximum depth of litter during the laying
period is more than 10 cm. The depth of litter was never more than 20 cm.

Table 1 Frequency of indoor housing systems for laying hens in Switzerland
FlocksName

Description

(%)

Hens
(70)

Deep litter systems

System with litter on the floor and droppings pit;manure removal at one level

34.1

18.0

Grid-floor systems

System without permanently accessible litter area on
the floor

17.0

16.8

System without any litter in the hen house

3.3

0.9

(2) with separable
litter area

System with litter area on the floor, but separable

1.1

0.4

( 3 ) with raised litter

System with raised litter area (central or along thewalls) which can also be separated

12.6

15.5

Multi-level system with litter on the floor and manure
removal at two or more levels

48.9

65.2

(1) without any

litter area

area
Aviary systems~

24

World's Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
Raised perches (at a height of at least 30 cm above the underlying surface) areprovided in 80.2% of the systems (i.e. in all aviary systems and in 62.7% of the
non-aviary systems). In the remaining systems perches are lower or the floors are
made of suitable slats that allow normal closing of the claws when the hen is
resting.
The mean (SD) stocking density in deep litter systems is 8.4 (1.4) hens per m2
compared with 8.6 (1.7) hens per m2 in aviary systems. However, in aviary
systems there are additional tiers above the main floor, so the density relative tothe floor area rises to 12.5 (4.7) hens per m2.
There is daylight in 81% of all poultry houses and 78% of all hens are
kept under natural daylight. The mean (SD) window area amounts to 4(2.2)%of the floor area. In 13% of the hen houses light intensity is below that
required to read a newspaper (less than about 5 lux). In big houses withseveral openings leading into a bad weather run or a free range area equalpressure ventilation systems are mainly used. In most of the houses (95.8%)
the food is provided from chain feeders. Drinking facilities usually consist ofnipples (80.2%) but cup drinkers (9.4%) are also used in some places. Protected
and darkened nest boxes are provided in all hen houses. In 15.6% of thehouses there are single nests (surface < 1100cm2, one nest for five birds), in
69.8% there are small group nests (1100-6000cm2, one nest for 11-60 birds)
and in 14.6% large group nests (>6000cm2) are used. Most of the single
nests (73%) have a bowl of plastic as nest ground, whereas corn chaff (13%),
mats of rubber-burl (7%) or coconut fibre (7%) are occasionally used. In group
nests the nest ground is often made of mats of rubber-burl (46Y0), Astroturf(texture of rough fibres of plastic; 30%), grids of plastic (14%) or corn chaff(11%).

Bad weather run. The sheltered and littered bad weather run, which isseparated from the free range area by a wall made of wire mesh, usually adjoins
the hen house on one or more of its sides. It enables the birds to experience fresh
air and an outdoor climate every day, even if the soil of the free range area is too
wet to be stepped on or is covered by snow. 54.9% of flocks have access to a bad
weather run. The mean (SD) littered area per hen in the bad weather run is 579(274)cm2 and 57% of the bad weather runs have a separate dust bath filled with
sand.
Free range area. Of the farmers who keep flocks with access to a free range
area, 69.4% started to do so between 1991 and 1997.53.3%of flocks in Switzerland(46.2%of the hens) have access to a pasture with a mean area of pasture per birdof 2.8m2 (2.4/8.1 m2). Correct management of the pasture area is necessary forregenerating damaged and burdened soil (e.g. pasture rotations and separation ofcertain areas for several weeks) so the area effectively accessible to the birds issmaller and 1.9m2 (0.5/4.8 m2) was calculated to be accessible to the hens at thetime of the visit. Although the hens are able to move a mean distance of 80m(50/150 m) away from the hen house, they actually only move 50 m (20/80 m). On
most pastures there were parts where the grass had been destroyed, especiallyaround the hen house and in shady places, but these bare areas (18% of thepastures) seldom amounted to more than 10% of the free range area.
The average estimated loss of hens to predators in the free range area was 6.7
birds per year per farm, but on 9% of farms the losses exceeded 20 birds.
World’s Poultry Science Journal, Vol. 56, March 2000

25

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et aI
ANIMALS

Hybrids. Pure flocks of white egg laying strains are more common thanwholly brown egg laying strains (55.7%and 33.470,respectively); with the balanceof flocks being mixtures of white and brown egg producers, white egg producers
make u p 64% of the total laying hen population surveyed. The most common
hybrids are Lohmann White-LSL (27.6%),Hypex HN (18.17), ISA Brown (17.1%)
and Lohmann Brown (8.8%).
MORTALITY

The mean (SD) mortality rate of laying hen flocks in Switzerland is 0.69 (0.57)%
per 28 days. There are significant differences (ANOVA, DF,, 136, F ratio = 4.86, p= 0.009) in the mortality rates of flocks without access either to a bad weather runor to a free range area (0.59 (0.49)%,n = 56), flocks with access solely to a bad
weather run (0.39 (0.20)%,n = 12) and flocks with access to a free range area (0.83(0.65)%,n = 71). Using Fisher’s method of least significant difference (95% LSD)
to distinguish these values, the mortality rate of flocks with access to a free range
area is shown to be significantly higher than that of flocks without any run, as
well as that of flocks with only a bad weather run.
The mortality rate of flocks without access to a free range area was examinedin the different housing systems. The mortality rate of flocks kept in deep litter
systems is 0.75 (0.741% (n = ll), that of flocks kept in grid-floor systems is 0.58
(0.46)% (n = 29) and that of flocks in aviary systems is 0.45 (0.28)% (n = 28).
Statistical testing does not reveal any significant differences (ANOVA, DF,, 65, F
ratio = 1.83, p > 0.1).
Comparison of the mortality rates of all pure flocks shows that the mortality
rate of white egg laying strains (0.55 (0.55)%,n = 54) is significantly lower thanthat of brown egg laying strains (0.80 (0.5917, n = 75; t = 2.45, p = 0.016).
Flocks with or without worm eggs in the droppings (see below) at the time ofthe visit had similar mortality rates (0.58 (0.46)%,n = 46 and 0.62 (0.66)%,n = 34,
respectively; I t I = -0.237, p > 0.1). The same was true for flocks with or without
coccidial oocysts in the droppings (0.62 (0.60)%, n = 54 and 0.55 (0.46)%,n = 26,
respectively; I t I = -0.533, p > 0.1).
LAYING PERFORMANCE

There was no significant difference (ANOVA, DF,, 86, F ratio = 1.42, p > 0.1)
between the performances of flocks without any access to a run (mean (SD) 1.6(5.71%above the VSGH standard curve, n = 311, those with access solely to a bad
weather run (5.1 (5.4)%,n = 8) or those with access to a free range area (2.6 (5.0)%,n = 51). A more detailed examination of flocks kept without access to a free range
area shows differences between housing systems (ANOVA, DF,, 36, F ratio 4.06, p= 0.026). Fisher’s test for least significant differences (95.0% LSD) revealed thatthe performance in aviary systems was significantly higher than that in grid-floor
systems (4.9 (4.5)%,n = 16 and -0.5 (5.1)%, n = 15, respectively), whereas nodifferences were found between aviaries and deep litter systems (2.4 (7.3)%,n =8) and between grid-floor systems and deep litter systems.
No significant difference was found between the performance of pure flocks ofwhite and brown laying strains (4.2 (6.1)%, n = 28 and 2.0 (4.2)%, n = 56,
respectively; I t I = -1.95, p = 0.055).
There was no difference in performance in flocks with or without worm eggs in
the droppings (see below) at the time of the visit (2.9 (4.4)%,n = 28 and 3.0 (6.6)%,

26

World’s Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandvy of laying hens in Switzerland: M . Hane et a1
Table 2 Plumage condition of flocks in different housing systems
Plumage index
Housing system

No. offlocksDeep litter systems
Grid-floor systems
Aviary systems

16
16
27

~

Mean

SD
4.0
3.2

10.6

4.8

*Statistically significant differences (p < 0.05, 95% LSD).

n = 20, respectively; t = 0.063, p>O.l). The same was true for flocks with orwithout coccidial oocysts in the droppings (3.3 (4.9)%, n = 31 and 2.3 (6.2)%,n =17, respectively; t = 0.636, p > 0.1).
CONDITION OF PLUMAGE AND FEATHER PECKING

In 28.6% of the visited flocks the majority of hens had nude spots > 5 cm indiameter (six flocks with induced moulting were excluded from the analysis). In
15.6% of the flocks the farmers estimated that more than 3% of hens had bloody
injuries caused by pecking, while in 10% of the flocks the farmer noted once orseveral times during the laying period a loss of birds from pecking of at least 1%
per month. In 50% of the flocks examined the farmers observed hens pecking at
the plumage of others or, in some rare cases, at themselves; 25.6% of farmers
observed that the birds were pulling out each others’ feathers and the same
percentage of farmers noticed birds eating feathers that had been pulled out or
picked u p from the floor.
A comparison of the average plumage indices of hens in different housing
systems showed that there are significant differences between flocks kept in gridfloor systems, deep litter systems and aviary systems (ANOVA, DF,, 56, F ratio =3.67, p = 0.032). Moulted flocks and flocks younger than 50 weeks or older than
70 weeks were excluded to minimise the influence of age (Table 2). Fisher’s test forleast significant difference revealed that the condition of the plumage of flocks
kept in grid-floor systems was significantly worse than that of flocks kept ineither deep litter or aviary systems. Provision of access to free range did not
significantly affect feathering (plumage index of 11.1 with and 11.9 without accessto free range, respectively; t = 0.719, p = 0.48, n1 = 28, n2 = 31).
In Switzerland 59.4%of the flocks (60.9%of the hens) are beak trimmed in orderto prevent the development of feather pecking. Beak trimming is usually done
once during the first 10 days of life but occasionally (8.4%of trimmed hens) at theage of 16-18 weeks when the pullets are moved from the rearing house to thelaying house. The usual procedure is to cauterise the tip of the beak by touchingit briefly with a hot blade. The use of anti-pecking devices such as vision
restricting plastic ’spectacles’, rings that prevent complete closure of the mandibleor ’bumpers’ protruding beyond the beak to prevent destructive pecking are
forbidden in Switzerland.
PARASITIC INFECTIONSWorm eggs were found in 62% of droppings samples; 50% of all flocks were
infected with Ascavidia galli, 20% with Tvichostrongylus tenuis, 18% with CapilWorld’s Poultry Science Journal, Vol. 56, March 2000

27

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
lavia spp., 7% with Hetevakis gallinavum and 2% with Raillietinu spp. In 49% of
the positive samples there were eggs from two or more different species ofworm. The infection rate was significantly higher in flocks having access to afree range area (75%) than in those without (43%; x21 = 10.40, p = 0.001).
Oocysts of Eimeria spp. were found in 67% of all samples. The infection rate of
Eim&ia was significantly higher in flocks having access to a free range area(73%) than in those without (43%; x21 = 9.20, p = 0.002). During the laying
period of the preceding flock, 77% of the farmers identified red mites(Devmanyssus g a l h u e ) in the poultry house.

Discussion
With the support of political measures and the acceptance of consumers,commercial egg production can be run successfully without the use of battery
cages in Switzerland. In 1991, the year egg production in battery cages wasabolished, 630 million eggs were produced and this number had increased to 663
million in 1997. During this time the percentage of home produced shelled eggs
increased from 62% to 73% of total shelled eggs consumed (Association of Swiss
Poultry Farmers VSGH, 199813).
The majority of hens are kept either in aviary or deep litter systems. These areoften combined with access to an outdoor area which usually includes a bad
weather run as well as a free range area. We found that the mortality andperformance of hens kept in aviary systems without access to a free range area
was similar to that reported for hens kept for breeding selection tests in battery
cages in Germany where, on average, 0.38% losses per 28 days and 309.9 eggs per
hen-day (day 141 to day 504) were found (Petersen, 1998). These findings are
similar to those of Blokhuis and Metz (1995) who reported that egg production
per hen in aviaries can equal that in battery cages. According to their report, thisalso holds true for the mortality rate, but only when the hens have had their beaks
trimmed. Appleby and Hughes (1991) stated that there was no evidence to showthat results were better in cages or in alternative systems, especially when the factthat more eggs are likely to remain uncollected in alternative systems is taken into
account. Our results show that flocks kept in grid-floor systems lay significantly
fewer eggs than flocks kept in aviary systems, whereas no difference was foundbetween flocks kept in aviary and deep litter systems.
Flocks with access solely to a bad weather run have fewer losses than flocks
with access to a free range area. In addition to the low mortality rate, access to abad weather run also has other advantages. Reduced stocking density with someof the birds outside enables weaker or pursued hens to withdraw and to get abetter opportunity to feed and it enables the staff to check hens and equipment
more easily. Furthermore, production of dust in the hen house decreases and air
quality is improved.
Whereas the mortality rate of flocks with access solely to a bad weather run islow, that of flocks with access to a free range area is high. There have been several
reports where predators, parasites, infection and unfavourable weather conditions have been discussed as possible causes for the increased losses (e.g. Laing,
1988; Tuller, 1996), but evaluating the complex interactions between environmental factors, infection factors and stress factors in the field is difficult. According to
the farmers, losses of hens from predation are not numerous, although problems
with local hawks do occur. Flocks with access to a free range area are more likely

28

World’s Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzedand: M . Hane et a1
to have coccidial oocysts and worm eggs than flocks without. However, thepresence of worm eggs or Eimeria oocysts does not correspond to a higher
mortality rate or a lower laying performance. Similarly, Permin et al. (1998) foundno significant differences in egg production between hens infected with Ascavidia
and those not infected.
There are still a number of problems to be solved in the management of freerange areas. Actual experiences of poultry farmers have shown that access to thefree range area has to be restricted because of damage to the soil near the henhouse and in shady places. High parasitic contamination near the hen house, as
found by Bray and Lancaster (19921, may be a risk to the health of the hens andwe therefore support the use of paddock rotation. The distribution of hens on thegrass could be improved by offering dispersed shadow facilities in order toreduce the risk of the accumulation of nitrogen and phosphate in highly
frequented places (Meierhans and Menzi, 1995). When giving advice on the
management of free range areas, one should keep in mind that 90% of theinspected flocks only use the pastures to a maximal distance of 80 m from the henhouse, and that some parts of the pasture generally have to be separated forrecovering the soil.
In alternative housing systems with access to a bad weather run or a free range
area the environment is not strictly controlled and more attention has to be paid
to the quality of the plumage. Partially defeathered birds, especially when
exposed to lower temperatures, experience increased heat loss associated with adecrease in feed efficiency (Deschutter and Leeson, 1986; Elliot, 1996).An analysisof the influence of the housing system on the plumage condition revealed thatflocks kept in grid-floor systems have significantly worse plumage than those
kept in deep litter or aviary systems. As feather pecking is regarded a major factor
in feather loss (Hughes, 1985; Elliot, 1996), it can be concluded that there are more
problems with feather pecking in grid-floor systems (i.e. systems without apermanent accessible litter area on the floor). This is supported by Blokhuis (1986)
and Huber-Eicher and Wechsler (1998) who found that provision of an
appropriate foraging material increases foraging behaviour and decreases thedevelopment of feather pecking. Thus, hens should be raised and kept withunrestricted access to a suitable litter substrate in order to reduce thedevelopment of feather pecking, to increase the quality of the plumage and, as aconsequence, to reduce economical losses through decreased feed efficiency.
Considering all these points and the fact that the management of litter anddaylight in the hen house requires additional skills, it is obvious that the staff
have to be well educated. Furthermore, the hens have to be adapted to these more
complex housing conditions. Hens that are going to be kept in aviaries, forexample, should also be reared in aviaries so that the use of the third dimension
and the equipment of aviary systems is improved when the hens are introduced
into their laying facilities (Frohlich, 1982; Gunnarsson et al., 1999; Huber-Eicher,1999).

Acknowledgements
We are grateful to the Federal Veterinary Office of Switzerland for the financial
support of the research project (No. 2.97.1), to Laurent Audig6 for his valuablecomments on the layout of the study and to Amanda Barnard for help with thetranslation.
Worlds Poultry Science Journal, Vol. 56, March 2000

29

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
References
APPLEBY, M.C. and HUGHES, B.O. (1991) Welfare of laying hens in cages and alternative systems:
environmental, physical and behavioural aspects. World’s Poulty Science ]onrnal 47: 109-128
ASSOCIATION OF SWISS POULTRY FARMERS VSGH (1998a) Tutigkeitsbericht 1997. Verband
Schweizerischer Geflugelhalter VSGH, Bern, Switzerland
ASSOCIATION OF SWISS POULTRY FARMERS VSGH (199%) Jahresbericht 1997. Verband
Schweizerischer Gefliigelhalter VSCH, Bern, Switzerland
BESSEI, W. and DAMME, K. (1998) Neue Verfahren fur die Legehennenhaltung. In: KTBL-Schrift
378. Kuratorium fur Technik und Bauwesen in der Landwirtschaft e.V. (KTBL), Darmstadt,
Germany
BLOKHUIS, H.J. (1986) Feather-pecking in poultry: its relation with ground-pecking. Applied Aninid
Rehavionr Scierice 16: 63-67
BLOKHUIS, H.J. and METZ, J.H.M. (1995) Aviary HOusiMg for Laying Hens. ID-DLO Institute forAnimal Science and Health, Lelystad, The Netherlands
BOCH, J. and SUPPERER, R. (1992) Vcferifzlirmed~z~if~scheParasitologie. Verlag Paul Parey, Berlin und
Hamburg, 4. Auflage, pp. 54-56
BRAY, T.S. and LANCASTER, M.B. (1992) The parasitic status of land used by free range hens. British
Poultry Science 33: 1119-1124
DESCHUTTER, A. and LEESON, S. (1 986) Feather growth and development. World’s Poultry Science
Iournal 54: 259-267
ELLIOT, M. (1996) Factors influencing feathering. Poultry International November: 80-81
FEDERAL VETERINARY OFFICE (1987) Bericlzte iiber die praktische Prufung auf Tiergevechtheit derLegehennenkufige Oekonom 165 und Scharbo 162 V. Bundesamt fur Veterinarwesen, Liebefeld-Bern,
Switzerland
FEDERAL VETERINARY OFFICE (19Y3a) Kurzbeschreibung der fur den Verknuf nicht zugelassenen
Haltungssysteme f u r Legehennen. Information Tierschutz 800.107.06, Bundesamt fur Veterinarwesen,
Liebefeld-Bern, Switzerland
FEDERAL VETERINARY OFFICE (1993b) Bericlit uber die praktische Prufung der Sclzruggitterhaltunqssysteme auf Tiergerechtheit. Bundesamt fur Veterinarwesen, Liebefeld-Bern, Switzerland
FEDERAL VETERINARY OFFICE (1W5) Kurzbeschreibung iler in der Schweiz verfiigbaren, sevienmussig
hergestellten Haltungssysteme f u r Legehennen. Information Tierschutz 800.107.04, Bundesamt fur
Veterinarwesen, Liebefeld-Bern, Switzerland
FROHLICH, E. (1982) Zum Einfluss der Aufzuchtbedingungen auf das Verhalten von Hennen. In:
KTBL-Schvift 291, Kuratorium fur Technik und Bauwesen in der Landwirtschaft e.V. (KTBL),
Darmstadt, Germany
FROHLICH, E. and OESTER, H. (1988) Anwendung ethologischer Erkenntnisse bei der Prufung derTiergerechtheit von Stalleinrichtungen und Haltungssystemen fur Legehennen. In: KTBL-Schrift
336, Kuratorium fur Technik und Bauwesen in der Landwirtschaft e.V. (KTBL), Darmstadt,
Germany
GUNNARSSON, S., KEELING, L.J. and SVEDBERG, J. (1999) Effect of rearing factors on theprevalence of mislaid eggs, cloaca1 cannibalism and feather pecking in commercial flocks of loose
housed laying hens. British Poultry Science 40: 12-18
HUBER-EICHER, B. (1999) A survey of layer-type pullet rearing in Switzerland. World’s Poultry
Science Journal 55: 83-92
HUBER-EICHER, B. and WECHSLER, B. (1998) The effect of quality and availability of foraging
materials on feather pecking in laying hen chicks. Animal Behauiour 55: 861-873
HUGHES, B.O. (1985) Feather loss as a problem: how does it occur? In: Proceedings of Second Euvopmn
Symposinm on Poultry Welfare, WPSA, Celle, pp. 177-188
LAING, P.M. (1988) Diseases of free range birds. World‘s Poultry Science lournal 44: 72-74
MEIERHANS, D. and MENZI, H. (1995) Phosphatbelastung ist problematisch. Schweizerisclie
Geflugelzeitung 8: 6-13
OESTER, H. and FROHLICH, E. (1986) Die Beurteilung der Tiergerechtheit der neuen Haltungssysteme fur Legehennen im Rahmen der Tierschutzgesetzgebung. Sclzzoeizer Archiv fur Tierheilkunde
128:521-534
PERMIN, A., NANSEN, P., BISGAARD, M. and FRANDSEN, F. (1998) Ascaridia galli infectionsin free range layers fed on diets with different protein contents. British Poultry Science 39:441-445

PETERSEN, J. (1998) Zusammengefasste Leistungspriifungsergebnisse 1995/96: In: Iahrbuch fur
Geflugelwirtschaft 1998. Verlag Eugen Ulmer, Stuttgart, Germany
SCHWEIZERISCHER BAUERNVERBAND (1998) Statistische Evhebungen wid Schatzungcn 1997.
Schweizerischer Bauernverband, Brugg, Switzerland

30

World’s Poultry Science Journal, Vol. 56, March 2000

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003

Husbandry of laying hens in Switzerland: M . Hane et a1
STEIGER, A. (1988) Swiss animal welfare legislation and the examination of housing systems. In:
Proceedings of the Fourth European Conference on the Protection of Farm Animals, Brussels, Belgium, pp.
89-92
SWISS SOCIETY FOR THE PROTECTION OF ANIMALS (STS) (1994) Laying hens: 22 years ofExperience with New Husbandry Systems in Switzerland. Kummerli & Frey AG, Bern, Switzerland
TANAKA, F. and HURNIK, J.F. (1992) Comparison of behaviour and performance of laying hens
housed in battery cages and an aviary. Poultry Science 71: 235-243
TULLER, R. (1996) Haltungssysteme fur Legehennen: Konventionell oder alternativ - Kompromissesind unvermeidbar. DGS Magazin Woche 27/96: 20-25
VAN HORNE, P.L. (1996) Production and economic results of commercial flocks with white layers inaviary systems and battery cages. British Poultry Science 37: 255-261
WECHSLER, B., FROHLICH, E., OESTER, H., OSWALD, T., TROXLER, J., WEBER, R. and
SCHMID, H. (1997)The contribution of applied ethology in judging animal welfare in farm animal
housing. Applied Animal Behaviour Science 53: 33-43

World's Poultry Science Journal, Vol. 56, March 2000

31

Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 10:30:01, subject to the Cambridge Core terms of use,
available at https:/www.cambridge.org/core/terms. https://doi.org/10.1079/WPS20000003