Increase in bone strength of spent laying hens housed in modified cages with perches.
The strength of the tibia was compared in 72-week-old ISA brown hens housed as groups of four for 52 weeks either in conventional cages or in cages with a 450 mm long perch, positioned either at the front or the back of the cage. The breaking strength of the bone was measured by subjecting it to a gradually increasing force on a three-point rig until it broke. The median strength of the tibia was greater in birds from cages with either front (160 Newtons [N]) or rear perches (152 N) than from conventional cages (135 N). Increased between-bird variation in the cages with perches suggests that there is scope for a further increase in bone strength by the provision of perches long enough to accommodate all the birds simultaneously. These results show that the strength of the tibia can be increased almost as much by using new designs of cage as by housing hens on the floor.
Hughes
B O
BO
Agricultural and Food Research Council Institute of Animal Physiology and Genetics Research, Roslin, Midlothian.
Appleby
M C
MC
D000818:Animals; D001842:Bone and Bones / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D005260:Female; D006799:Housing, Animal; D013977:Tibia / Q000502:physiology*