Table 2.

Effects of the experimental half on behaviour and physiology (medians + interquartile ranges). Only measures for which a significant effect was found using a Wilcoxon rank sum tests are shown, another 122 measure × situation × treatment combinations were tested but no significant batch effect was found. *** P < 0.001, ** P < 0.01, * P < 0.05.

Back pack	Situation	Measure	First period (day 0–7)	Second period (day 8–15)	Z
Yes	Holding pen	% time spent preening	3 (0–24)	45 (17–56)*	−2.5
	Home pen – Immediately after release	Equipment pecks received/min	2.0 (0–3.1)	0 (0–0)*	2.4
		% time standing	39 (24–49)	7 (7–9)***	3.8
		% time walking	11 (7–16)	3 (2–9)*	2.0
	Home pen – 2–7 days after equipping	Body pecks received/min	0.02 (0–0.05)	0 (0–0)*	2.5
		Equipment pecks received/min	0 (0–0.02)	0 (0–0)*	2.2
		% time feather pecking (gentle)	0 (0–0.12)	0 (0–0)*	2.2
		% time standing	19 (10–21)	9 (6–12)*	2.0
		% time on ramp	0.2 (0–1.5)	0 (0–0)*	2.0
	0–7 days after equipping	Weight gain (kg)	0.19 (0.16–0.23)	−0.01 (−0.03–0.06)**	2.7
No	Holding pen	Wall pecks/min	3.9 (3.2–4.7)	1.1 (0.1–2.3)***	3.4
	Home pen – Immediately after release	Wall pecks/min	0.2 (0–0.4)	0 (0–0)*	2.4
		% time walking	35 (22–56)	17 (12–21)*	2.3
		% time eating/drinking	3 (0–8)	66 (8–75)*	−2.1
	Home pen – 2–7 days after equipping	% time walking	7 (5–10)	11 (8–13)*	−2.0
	0–7 days after equipping	Weight gain (kg)	0.19 (0.17–0.22)	0.04 (0.01–0.07)**	3.0
	Immediately after equipping	Eye temperature	30.1 (29.9–30.7)	31.0 (30.3–31.6)*	−2.3