109. These systems include deep litter, perchery, aviary and
free range. They provide various degrees of freedom of movement
and facilities to encourage normal behaviours but at the cost of
large group sizes and the increased likelihood of injurious
pecking and cannibalism.
110. In 1991 the Council published its Report on the Welfare
of Laying Hens in Colony Systems. We stand by the majority of
recommendations in that report. Nonetheless, we believe that the
industry has developed and improved systems since then and we
wish to update a small number of the recommendations on the basis
of recent information about best industry practice.
111. We urge the Government to pursue implementation of
recommendations made in the Report on the Welfare of Hens in
Colony Systems (1991) and accepted in the Government response for
implementation on an EU basis (some of these are modified in the
following paragraphs). The forthcoming EU review offers an ideal
opportunity to do this.
112. Sufficient individual or communal nest boxes should be
provided in colony systems to allow daily access for all hens.
113. Best practice within the industry would suggest that
individual nest boxes should be provided at a rate of at least
one for every five or six hens and that communal nest boxes
should be provided at a maximum rate of 120 birds/mē of nest box
area, dependent on well designed nest boxes and the appropriate
strain of bird.
114. In the various non-cage systems currently in use, hens
need 15cm of perch length (dependent on their size and the
system) in order that all birds may perch at the same time. More
perch length is required in non-cage systems than in enriched
battery cages because of increased competition.
115. We recommend a minimum perching allocation of 15cm
length per hen in non-cage systems, provided that the system
design allows easy perch access.
116. We continue to stress the need for sufficient feeders and
drinkers to enable all hens to obtain adequate feed and water and
so meet the requirements of the Welfare of Livestock Regulations
1994.
117. We accept industry best practice and recommend
allowing a maximum of 100 hens per standard bell-type drinker or
10 birds per nipple or cup drinker.
118. We re-iterate our earlier recommendation for a minimum
provision of 10cm of linear feed trough length per hen (i.e. 5cm
each side). We also now recommend at least 4cm per hen of the
perimeter when circular feeders are used.
119. We believed in 1991 that a flock size of a maximum of
2000 was realistic. This figure was not accepted then by
Government and in 1997 we have no clearer evidence of what the
figure should be. There is commercial experience to suggest that
larger group sizes can operate satisfactorily.
120. Research is needed to establish optimum flock sizes
for laying hens.
121. These are flock systems in which the hens are confined to
a building with access to an area littered with material such as
wood shavings or straw. A raised, perforated floor is often
incorporated. The accommodation is usually in a building with a
controlled environment. The EC Egg Marketing Regulations state
that the maximum stocking density should be 7 birds/mē. This was
the figure recommended in our 1991 Report.
122. Deep litter summary assessment:
Pros:
- Varied physical environment and an opportunity to express
a wide range of behaviours.
- No exposure to predators.
- Freedom to move within the house.
- Provision of nest boxes, perches and dust bathing
facilities is relatively easy.
- Easier to inspect birds than in cage systems.
- Improved bone strength due to increased activity.
- Can be combined with access to range.
- Light level and period easily controlled throughout the
year.
Cons:
- Beak trimming may be required.
- Large colony size increases risk of social disharmony.
- If feather pecking or cannibalism occur, control may be
difficult.
- Increased risk of endoparasites and ectoparasites due to
access to droppings.
- Disinfection and disinfestation may be difficult
following depopulation.
- Stocking density is sometimes insufficient to achieve
optimum temperature range under cold ambient conditions.
- Management of litter may be difficult during winter
months.
123. These are usually floor based with tiers of floors or
perches at several levels, sometimes with an area of litter on
the floor. Feed, water and nesting accommodation are located at
more than one level. The systems are normally in controlled
environment buildings.
124. The Report on the Welfare of Laying Hens in Colony
Systems (1991) recommended that hens in perchery or aviary
systems should be stocked at no more than 15.5 hens/mē. This has
subsequently become industry practice and appears to work well.
125. Perchery and aviary systems summary assessment:
Pros: As for deep litter systems plus;
- Provision of perches and other facilities at different
heights which allow a greater use of space.
- Higher stocking densities make temperature control easier
in cold weather.
- Birds can escape aggression by moving within the house.
Cons: As for deep litter systems plus;
- Furniture structures in the house may impede observation
and inspection.
- Hens can be injured by falling between levels or flying
into furniture.
- Birds can become soiled from above unless manure belts
are provided or perches are placed carefully.
- Difficult to depopulate.
- High risk of injurious feather pecking and cannibalism,
thus beak trimming is often necessary.
126. Hens can be housed on deep litter or in perchery or
aviary systems and the EC Egg Marketing Regulations state they
must further be provided with continuous day time access to land
mainly covered with vegetation.
127. Free range summary assessment:
Pros: As for perchery and aviary systems plus;
- Freedom to access the range area and thus express a wide
behavioural repertoire.
- Opportunity to graze on vegetation and to augment and
vary diet.
- Opportunity to dust bath in soil.
Cons: As for perchery and aviary systems plus;
- Predation or fear of predation may be a problem.
- When outside, birds may suffer discomfort due to climatic
extremes.
- Large pop holes can adversely affect environmental
conditions within the house.
- Disease risk due to access to droppings and contact with
wild birds.
- Beak trimming is essential because of group sizes and
high levels of natural light.
- Pasture management is an additional requirement.
128. For free range hens, we recommend that the maximum
stocking density of 1000 birds per hectare is maintained. We
agree with industry practice that a maximum distance of 350 m
from the poultry building should be allowed for the purpose of
calculating the total number of birds that may be kept in an
enclosure.
129. It is important to establish a system of rotation of
grazing or house movement in order to prevent poaching and build
up of disease.
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