. 2016 Jul 21;95(11):2489–2502. doi: 10.3382/ps/pew236

Table 1.

Comparison of capacity of the aviary system to accommodate hens in the various levels with the maximum number of white (DW or W36) and brown (BB or HB) hens observed at different times of the day.

	Capacity¹ (# hens)					Maximum # of hens observed

Location	Floor	Perches	Ledges	Nests	Combined	MORNING		MIDDAY		EVENING		DARK

						White	Brown	White	Brown	White	Brown	White	Brown
Lower tier	37 (61)	48 (48)	–	–	85 (109)	68^a,*	49^a,†	58^a,*	67^a,†	48^a,§	74^a,†	38^a,*	50^a,†
						62^b,§	61^b,†	51^b,§	43^b,†	29^b,§	69^b,†	39^b,*	60^b,†
						68^c,*	71^c,†	41^c,§	44^c,†	23^c,§	59^c,†	44^c,*	73^c,†
Middle tier	31 (51)	48 (48)	8 (14)	–	87 (113)	57^a,*	59^a,†	59^a,§	67^a,†	71^a,*	56^a,†	57^a,§	63^a,†
						62^b,*	57^b,†	31^b,§	73^b,†	54^b,§	48^b,†	51^b,§	57^b,†
						60^c,§	48^c,†	27^c,§	38^c,†	37^c,*	32^c,†	53^c,§	49^c,†
Upper tier	10 (17)	16 (16)	8 (14)	13 (21)	47 (68)	42^a,§	72^a^,^†	50^a^,^§	40^a,†	47^a^,*	33^a,†	96^a^,^§	53^a^,^†
					34 (47)²	43^b,§	66^b^,^‡	31^b,*	25^b,†	36^b^,^§	23^b,†	106^b^,^§	54^b^,^†
						37^c,*	59^c^,^†	26^c,§	18^c,†	37^c^,^§	21^c†	96^c^,*	49^c^,^†
Litter	90 (133)	16 (16)	–	–	106 (149)	–	–	110^b^,*	48^b,†	69^b,§	43^b,†	–	–
								89^c,*	74^c,†	84^c,*	70^c,†

¹Perching space was calculated at 15 cm/hen following the United Egg Producers (2016) guidelines, while the space required to accommodate a standing hen was calculated at 929 cm²/hen as per United Egg Producers (2016) recommendations for multi-tier systems and (presented in parentheses) at 563 cm²/standing hen following kinematic analysis of hen space requirements for Hy-Line W36 by Mench and Blatchford (2014). Note that United Egg Producers specifies that only floor area and tiers should be counted at usable space when calculating stocking density (United Egg Producers, 2016).

²Nest areas closed automatically 2 h before lights off, and this space was not available during the dark period, further reducing the floor space available in the upper tier. Bold numbers indicate hen numbers above capacity. Different letter superscripts represent different periods of time relative to hens gaining litter access:

^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 had gained access to litter. Different symbol superscripts represent different strains of hens:

*DeKalb White hens (DW);

^†Hyline brown hens (HB);

^‡Bovans brown (BB). and

^§Hyline W36 hens (W36);