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FOR MORE than 20 years the welfare of laying hens kept in battery cages
has been the focus of argument and controversy. Yet few poultry farmers
have adopted economically viable alternatives to the cage. Although large
scale free-range and perchery farms are more common than they were 10 years
ago, they have not seriously challenged the ubiquity of the battery cage.
Switzerland and Sweden have decided to ban battery cages after 1992 and
1998 respectively, and have set up intensive research programmes into viable
alternatives . Real improvements in welfare can be achieved only by developing
housing systems that take account of both the physical and behavioural needs
of hens. In our previous article (‘No room for manoeuvre’, New ÐÓ°ÉÔ­´´,
16 September 1989) we argued that hens need more space. Here, we argue that
they need a lot more besides.

A good place to begin thinking about what a hen needs for a decent life
would be in the jungles of Southeast Asia where, with persistence, one can
track the red jungle fowl ancestors of the domestic chicken. These wary
birds live in small groups of between four and six, and are highly active
during the day – walking, running, flying, pecking and scratching for food,
and preening. At night they roost together in the trees. Domestic chickens
released on islands off Queensland, Australia, and the west coast of Scotland
showed remarkably similar patterns of behaviour. David Wood-Gush and Ian
Duncan, of the Agricultural and Food Research Council’s Edinburgh Station,
observed that the Scottish birds formed small, discrete social groups which
spent much of their day foraging either separately or together, then returning
at dusk to roost. The hens concealed their nests and raised and defended
their broods. In short, there is no evidence that genetic selection for
egg laying has eliminated the birds’ potential to perform a wide variety
of behaviour. The term ‘free-range’ perhaps conjures up an image of small
groups of chickens living a semi-wild existence among a rich variety of
vegetation. Such an environment would appear to be almost natural. With
proper protection from predators and extremes of climate, this might also
be the best, if not the cheapest, way to keep hens.

But many free-range farms do not begin to approach this idyll. Often,
one large central house is provided for a flock of up to 4000 hens. Inside,
hens may have less space than they would in battery cages. In theory, of
course, they can always go outdoors and run around but, in practice, only
a few birds venture out. This may be because they never find an exit, because
they are prevented from going out by dominant birds, or because the outside
has little to offer. Most free-range farms provide open grassland for the
birds rather than dense, varied vegetation. Hens appear reluctant to venture
too far from the house into these wide open spaces. All too often the result
is a patch of mud near the house and overgrown, unused grass further away.

Percheries remove birds yet further from the jungle situation of their
ancestors. Again, birds are kept in large densely packed flocks but this
time without access to the outside at all. Under the marketing regulations
set by the European Commission, eggs can be legitimately described as ‘perchery’
or ‘barn’ eggs even though the birds have had only 400 square centimetres
of floor space and a perch 15 centimetres long – in other words, less floor
space than they would get in a battery cage. Timid birds may find it difficult
or impossible to gain access to the perches, dust-bathing areas and nests.

A closer look at current husbandry practice reveals that battery cages
actually have some decidedly good points. They do at least keep the birds
clean and reduce the risk of diseases, such as coccidiosis, which can be
a real problem when densely packed birds spend a great deal of time pecking
among their own faeces in dirty shavings or earth.

The necessities of life

So at present no system can be unhesitatingly recommended as good for
the hens’ welfare. Given that most families are unlikely to start keeping
small flocks in their own gardens, we must find a better way of keeping
large numbers of hens together. Perhaps the answer lies with scientific
studies that can establish what hens really need. A list of their own priorities
would be a useful starting point.

It is relatively easy to establish the basic preferences of hens for
various aspects of their environment. Many studies have demonstrated, for
example, that hens prefer large to small cages, litter to wire floors, the
company of familiar to strange birds, and the presence of loose material
(such as oat husks or straw) to fixed synthetic grass as a nesting material.
But this evidence is not enough to prove that hens will suffer if they have
to ‘make do’ with a less-preferred option. So the next step is to find out
how strong these preferences are. If the preference for, say, a litter floor
with loose material over a floor made of wire is so strong that birds are
willing to pay a high ‘cost’ to get it, then litter is not just something
that hens like but something that really matters to them.

There are a variety of ways in which a cost can be imposed on a hen.
Ian Duncan and Vivian Kite, at Edinburgh, found that hens would consistently
‘run the gauntlet’ of water-filled foot baths, unpleasant blasts of air,
or weighted swing doors in order to reach a nest box. The fact that hens
‘insist’ on using a nest box even when it is made difficult for them suggests
that the absence of nest boxes in standard battery cages is a deprivation
that matters to the birds. Norma Bubier, of the zoology department at the
University of Oxford, also found evidence of the importance of nest boxes,
using slightly different methods. She imposed a cost by making hens do something
they dislike – squeezing through a small gap – to reach a variety of things
that they might want, such as food, water, nest box, perch, grass or litter.
Hens chose to enter a nest box the same number of times whether or not they
had to squeeze through the gap. Other manipulations, such as changing the
day length or presenting distracting objects, also did not lessen a hen’s
attraction to a nest box, even though these affected other aspects of behaviour.

Like most animals, hens will work hard (by pecking keys or squeezing
through gaps) for access to food. But what is more surprising is that, even
if they are provided with plenty of food, freely available in front of them,
the birds will often spend a great deal of time pecking and scratching at
the ground while foraging, even though they could eat without doing this.
Marian Dawkins, at the University of Oxford, found that semi-wild jungle
fowl in a wood at Whipsnade Park Zoo spent up to 60 per cent of their active
time pecking the ground. Norma Bubier found that domestic hens given food
mixed in with litter, so that they had to search for everything they ate,
spent exactly the same amount of time ‘feeding’ as birds provided with food
in a hopper. The hopper-fed birds, which could eat more rapidly, spent the
‘extra’ time pecking and scratching in litter, even though there was no
food there. It would appear that pecking in association with food is so
much part of the natural feeding behaviour of hens that the animals seem
to ‘need’ to peck and scratch even if they are not hungry at all.

So evidence to date suggests we must allow hens to nest and to indulge
in a range of food-pecking behaviour, wherever we house them. It would be
foolish to suggest this is the end of the story. Hens may also ‘need’ to
dust-bathe, or to peck in other contexts, and researchers are now investigating
these possibilities. But we are slowly learning about what may be crucial
to a hen, and what may be more of a ‘luxury’.

One recent experiment, for example, demonstrated that the mouldability
of a nest may matter more to a hen than the presence of loose material to
peck at. Duncan and Kite found that hens chose to nest on bean bags, rather
than on unmouldable nest floors surrounded by peckable material.

We may know more about what to provide for hens than we did 10 years
ago, but there is another side to the coin. We must also decide what to
avoid. Preference tests have shown that hens do not approach strange groups
of birds when they have the chance. In experiments where birds have been
forced to meet strangers, the birds suffered several deleterious consequences
such as increased heart rate, enlarged adrenal glands, raised levels of
the ‘stress’ hormone corticosterone, and increased aggression and fearfulness.
Although we do not yet fully understand how hens recognise each other, it
seems unlikely that birds will become familiar with the hundreds or even
thousands of birds they may meet in a large perchery or free-range unit.
To be in the constant presence of strangers must be a nightmare (and may
sometimes result in mortality of up to 15 per cent). These facts alone should
be enough to persuade us that birds should not be kept in large groups.
If this is not enough, the fact that cannibalism is more difficult to control
in larger groups should be compelling.

The immediate cause of cannibalism is usually severe feather pecking.
But the reasons why birds begin to peck each other’s feathers are complex.
In cages, feather pecking occurs particularly during the afternoon when
hens have finished feeding and laying eggs, and have little else to do.
Hens in aviaries mostly feather peck in areas where ground pecking is impossible.
Thus, although dietary deficiencies and lighting patterns may both play
a part, the major cause may be a lack of suitable pecking material. So poultry
farmers should provide pecking materials not only because hens ‘need’ to
peck but because the consequences of deprivation may be fatal.

Equipped now with at least some information about what must be provided
and what avoided, we should be able to suggest improvements to existing
systems. The battery cage, with its in-built advantages of hygiene and small
group size, needs to be altered to allow hens to perform their behavioural
‘needs’. On the other hand, facilities such as nests or dust-baths may be
easier to provide within the framework of a perchery or free-range system;
in these housing systems, we should encourage birds to stay within small
subgroups, and to peck at something more benign than each others’ feathers
or faeces.

Work on improved cages began in the early 1970s with the so called ‘get
away’ cage. Most of this work was carried out at the Institute for Small
Animal Breeding at Celle in West Germany. The cage houses birds in groups
of between 20 and 60 with nests, sometimes dust-baths, and perches at different
heights to allow birds to escape from each other. At the ADAS Experimental
Husbandry Farm at Gleadthorpe in Nottinghamshire, Arnold Elson has developed
a different system for groups of a similar size. His ‘terrace’ confines
birds to wire cages, with perches and nest boxes, until they have laid their
eggs. A door then opens allowing the birds to move down a stairway to a
litter area where they can scratch and dust-bathe before returning to the
wire area in the evening to feed. This avoids a serious problem in many
other systems – that of birds laying eggs in uncollectable places. Even
with groups of these sizes, however, aggression and cannibalism have occasionally
been a problem. Work on cage design in Edinburgh by Mike Appleby and Barry
Hughes, and at the University of Bristol’s Veterinary School by Heather
Reed and Christine Nicol, concentrates on the provision of facilities within
cages for groups of about four – a group size much closer to that selected
by hens themselves. These cages contain perches that the birds use extensively,
improving the condition of their feet and the strength of their leg bones.
All current designs also incorporate some form of nest for the hens – a
traditional wood-shaving lined box or a simple depression flush with the
floor of the wire cage. The researchers are investigating how many nests
a group of four birds need, as they do not easily share just one.

In a recent trial at Bristol, hens were given three nests for four birds.
This appeared to work well as the birds laid more than 99 per cent of eggs
in the nests over a five-month period. The birds strongly preferred nests
that were lined with mouldable rubber to those of bare plastic. In addition,
they spent more time, and laid more eggs, in lined nests that had a variety
of peckable objects (plastic cable ties, copper wire and small squares of
carpet) attached to the cage wall just above the nest.

Little other work has been done on the provision of peckable materials
for caged hens, although one study showed that cut straw placed in baskets
reduces feather pecking in hens kept on wire floors. In one Norwegian study,
caged hens were provided with a plastic matrix of blue spots just below
their cage floor. All birds pecked at this more than a conventional floor,
but the effect was enhanced by imprinting the birds on blue food as chicks.
These birds ended up with significantly better plumage.

Important as these developments are, there are some things a cage will
never provide – the opportunity to fly, or to explore unfamiliar territory,
for example. If future research shows that these are also essential to health,
or are behavioural ‘needs’, birds would have to be given access to much
larger, relatively unconfined spaces. How could this be done economically
without running into problems associated with poor hygiene and large group
size? Our suggestions are unfortunately highly speculative, as little or
no research on these subjects has yet been published. Common sense would
suggest that if hens could be encouraged to spend more time engaged in harmless
pecking they might spend less time pecking feathers or faeces.

The provision of attractive materials in tubs or baskets could divert
birds to some extent. But more can be learnt from the experience of workers
in zoos, where environmental enrichment programmes have received growing
attention over the past decade. David Sheperdson at the London Zoo has been
giving a variety of species the opportunity to hunt for their food. Meerkats,
for example, have been given a mealworm dispenser – in reality, nothing
more than a tube with holes along the side through which mealworms fall
at irregular intervals. The meerkats spent a great deal of time digging,
foraging and scrabbling at the tube. Chimpanzees have an artificial ‘termite
mound’ where they have to use sticks to get their food. The animals seem
to prefer to perform these natural patterns of behaviour even if a free
supply of zoo diet is available. Chickens, similarly, will work for part
of their diet by repeatedly pecking a key or disc connected electronically
to a food delivery machine, even in the presence of freely available food
of the same type. It should not be difficult to provide hens with such simple
‘operant’ feeders in addition to their free food, or with feed troughs designed
to encourage foraging actions.

The simplest way of dividing up a large flock of birds, so that they
remain in small groups, would be to erect some type of physical barrier.
But taken to its logical conclusion this brings us back to the cage. No
one has yet come up with a good alternative solution. We believe there may
be other ways of encouraging birds to stay voluntarily in smaller groups,
but no research has been done on this. A bit of lateral thinking may by
needed here.

One possibility that is worth exploring would be to imprint young chicks
onto specified colours or objects. Small groups would then have their own
unique markings provided in key areas of the house. A second possibility
would be to provide infertile cockerels (or masculinised females that behaved
like males) to attract and guide their own group of hens around the house,
but without producing undesirable fertile eggs for the consumer. Cockerels
might also encourage timid hens to venture out in free-range units, especially
in the presence of more diverse vegetation.

Perhaps a cage, transformed with nests, operant feeders and perches,
and providing hens with considerably more space than they have now would
actually not differ much from a modified perchery. Maybe different research
programmes will ultimately converge. In the meantime, no scientist or consumer
can afford to be complacent. Research may be gathering momentum but hens
have little to thank us for so far. Their welfare in any system remains
far from assured.

* * *

The Swiss declare war on the battery cage

FARMERS in Switzerland have been prohibited from installing new battery
cages since 1981. By 1992, groups of 40 birds or more must have access to
perches and nests and a minimum of 800 square centimetres of wire-grid floor
space each. The Swiss began intensively studying alternatives to the battery
cage in the late 1970s. Construction firms that devise new models have to
pay to have the system evaluated by the Federal Veterinary Office.

So far, five models, mainly aviaries with wire floors, have been passed
as suitable in welfare terms. The Swiss Poultry Husbandry School at Zollikofen
is evaluating the economics of these alternatives. A recent survey of farms
with more than 500 birds concluded that eggs produced in these systems cost
an average of 8 per cent more than battery eggs, due to the high labour
and investment costs.

Researchers at Zollikofen estimate that the average consumer is willing
to pay only 3 Swiss francs more per year for eggs. The alternative systems
are already nearly cheap enough to meet this demand. Each Swiss citizen
consumes on average 180 eggs per year, 65 per cent of which are produced
in Switzerland. So a consumer who purchased only Swiss eggs would pay 4
Swiss francs more per year. Sweden is also evaluating alternative systems,
borrowing heavily on the development work already done in Switzerland. Much
of this work is underway at the Swedish Agricultural University in Skara.

Dr Christine Nicol is a lecturer in the department of animal husbandry
in the Veterinary School of the University of Bristol. Dr Marian Stamp Dawkins
is Fellow in Biology at Somerville College, Oxford, and works in the department
of zoology at the University of Oxford.