. 2019 Jan 7;98(5):1935–1946. doi: 10.3382/ps/pey574

Table 1.

Comparison of capacity of the aviary system to accommodate hens in the various levels with the maximum number of white (W1 or W2) and brown (B1 or B2) hens ever observed in those areas during nighttime observations.

				Maximum # hens observed
	Estimated capacity in # hens¹			Wire floor		Perches		Ledges
Location	Wire floor	Perches	Ledges	White	Brown	White	Brown	White	Brown
Lower tier	37	48	-	11^a*	49^a^‡	9^a*	31^a^†	-	-
	(108)	(48)		32^b*	21^b^‡	45^b*	7^b^‡	-	-
	[64]	[39]		21^c*	69^c^‡	13^c*	30^c^†	-	-
Middle tier	31	48	8	13^a*	27^a^†	13^a§	20^a^‡	25^a§	14^a^‡
	(90)	(48)	(25)	45^b*	55^b^†	19^b§	43^b^†	37^b*	12^b^†
	[54]	[39]	[15]	12^c*	41^c^‡	9^c*	36^c^‡	25^c§	9^c^†
Upper tier	10	16	8	64^a§	22^a^†	25^a*	12^a^‡	30^a§	14^a^‡
	(31)	(16)	(25)	14^b§	37^b ^‡	11^b§	17^b ^†	16^b*	13^b^‡
	[18]	[13]	[15]	43 ^c *	28^c^†	24 ^c ^§	6^c^‡	30^c§	11^c^‡

¹Perching space was estimated at 15 cm/hen following the UEP (2017) guidelines. The space required to accommodate a hen on the floor and ledges was estimated at 929 cm²/hen as per UEP (2017) recommendations for multi-tier systems, at (the number presented in parentheses) at 318 cm²/lying hen following kinematic analysis of hen space requirements by Mench and Blatchford (2014), and at [the number presented in square brackets] 538.3 cm²/lying hen and 18.6 cm/hen perching space following space use analysis of Hy-line W36 hen space requirements by Riddle et al. (2018). Bold typeface indicates hen numbers above UEP (2017) recommended capacity. Different letter superscripts represent different periods of time relative to hens gaining access to the floor litter area: ^aPRE is the period before hens had litter access; ^bIMM is the period immediately after hens had litter access; and ^cACC is the period 3 wk after hens gained access to the floor litter area. Different symbol superscripts represent different strains of hens: *W1, ^§W2, ^†B1, and ^‡B2.