Free range systems provide significant animal welfare
improvements when compared to battery cages (greater ability to express a range
of natural behaviours is an obvious example). However, they still incur serious
welfare problems, as this new study demonstrates.
Anon. Free-range or battery: what difference? Vet Practice [UK] 2010; 42(7): 40,
Laying hens are just as likely to suffer serious welfare problems when housed
under free-range conditions as they are in intensive battery production systems,
researchers at Bristol veterinary school have discovered.
Anna Davies, a postgraduate student in the animal welfare and behaviour group,
described a study looking at spent hens in the run-up to depopulation at around
72 weeks of age.
She pointed out that many of the welfare issues of most concern to consumers,
animal welfarists and the industry are cumulative and so they are best measured
at the end of the birds?’ working lives. It must be remembered, however, that
the findings may underestimate the severity of welfare problems if birds with
more obvious injuries are culled or die earlier in the production cycle.
Miss Davies and her colleagues captured 50 birds each from 25 free- range layer
flocks throughout the UK and examined them for various injuries which would
indicate poor welfare. They found that nearly half the birds had plumage damage,
over 30% had peck injuries around the vent, while 20% had vent prolapses and
more than 60% had potentially painful injuries to the keel bone.
It is a concern that many of the more serious injuries, like keel bone fractures
and prolapses, are unlikely to be spotted during the sort of cursory inspections
that the birds would undergo in a normal production system. The injuries are
only apparent if the birds are held individually and examined closely.
She pointed out that this high prevalence of injuries occurred in hens from six
different genetic strains and kept in several different types of housing system.
?“So we must ask ourselves if the modern laying hen is robust enough for the
conditions in which they are kept and whether we should be looking at
selectively breeding healthier birds,?” she said.
Keel fractures are seen much more frequently in these free-ranging birds than in
those kept confined in battery cages. This would appear to be the penalty paid
for allowing birds to follow their instincts in seeking out high-level perches,
as they probably are caused by the birds colliding with these structures.
But it must be remembered that battery cages cause their own welfare problems
which are likely to be just as severe, she said.