ABSTRACT A major skeletal problem of conventionally
caged hens is increased susceptibility to osteoporosis
mainly due to lack of exercise. Osteoporosis is characterized
by a progressive decrease in mineralized structural
bone. Whereas considerable attention has been
given to enriching laying cages, little research has been
conducted on providing caged pullets with furnishments,
in particular perches. The objective of the current
study was to determine if metal perches during all
or part of the life cycle of White Leghorns affected hen
musculoskeletal health, especially at end of lay. Treatments
during the pullet phase (hatch to 16.9 wk) entailed
cages with and without perches. Four treatments
were used during the laying phase (17 to 71 wk of age).
Treatment 1 chickens never had access to perches at
any point during their life cycle, typical of egg industry
practices in the United States for conventional cages.
Treatment 2 chickens had access to perches only during
the egg-laying phase, which was from 17 to 71 wk of
age. Treatment 3 chickens had access to perches only
during the pullet phase (0 to 16.9 wk of age). Treatment
4 chickens had perch access throughout their entire life
cycle (0 to 71 wk of age). Musculoskeletal health was
assessed by measuring muscle weights, bone mineralization,
bone fracture incidence, and keel bone deviations.
Muscle deposition of 71-wk-old hens increased when
given access to perches as pullets. Bone mineralization
of 71-wk-old hens also increased if given perch access
as adults. However, the disadvantage of the adult perch
was the higher incidence of keel deviations and keel
fractures at end of lay. The increase in bone mineralization
of the keel bone as a result of perch access during
the pullet and laying phases was not great enough to
prevent a higher incidence of keel bone fractures at end
of lay. Perch redesign and placement of perches within
the cage to minimize keel fractures and deviations are
possible solutions.