Table 2.

Effect of strain and age on perch usage in aviary systems.

Age (wk)	Strain	Mean	CI
		Odds1
	Brown	0.41b	0.33–0.50
	White	0.74a	0.61–0.89
15		0.82a	0.70–0.96
25		0.41b	0.34–0.50
35		0.50b	0.41–0.59
Treatment comparisons		Odds ratio2
	Brown vs. White	0.56	0.43–0.74
15 vs. 25		1.99	1.64–2.42
15 vs. 35		1.65	1.36–2.01
25 vs. 35		0.83	0.67–1.02
Source of variation		P-values
Strain		0.0004
Age		0.0001
Age×strain		0.590

^a-bMeans within a column lacking a common superscript differ (P ≤ 0.05).

¹Odds of observing hens using perches over not observing them for each treatment group.

²Ratio of the odds of observing hens using perches for 2 treatment groups.