Table 3.

OR estimates and 95% CI of having a keel bone fracture. An OR > 1 indicates that birds were more likely to have a keel bone fracture, whereas an OR < 1 indicates that birds were less likely to have a keel bone fracture. The number (n) and percentage (%) of laying hens with a keel bone fracture at baseline (week 0) and six weeks after wing damage (unclipped, half-clipped and full-clipped) in white- and brown-feathered birds of two strains (white- and brown-feathered), and of the three treatment groups are included.

treatment	n (%)	OR	95% CI
week
week 0	46 (41.4%)	ref.	ref.
week 6	54 (48.6%)	1.43	0.82–2.48
strain
brown	47 (46.1%)	ref.	ref.
white	53 (44.2%)	0.9	0.57–1.73
clipping
unclipped	39 (44.3%)	ref.	ref.
half-clipped	36 (52.9%)	1.4	0.73–2.65
full-clipped	25 (37.9%)	0.71	0.36–1.41