Table 1.

Immediate effects (within 2–2.5 h) of enrichment withdrawal on 991 comb temperature, 991 face temperature and 979 eye temperature measurements from 56 hens. Key explanatory variables are underlined; other variables control for behaviour and body position relative to the camera at measurement. Data were analysed using LMM with hen identity as a random effect.

Variable	Comb			Face			Eye
	Coef ± S.E.	t	P	Coef ± S.E.	t	P	Coef ± S.E.	t	P
Intercept	14.80 ± 21.20	0.70	0.49	59.9 ± 4.85	12.35	<0.0001	52.51 ± 5.16	10.17	<0.0001
Treatment - Control	−0.38 ± 0.54	−0.70	0.49	0.03 ± 0.08	0.36	0.72	−0.08 ± 0.10	−0.79	0.43
Phase - post-withdrawal	−3.48 ± 0.52	−6.64	<0.0001	−0.70 ± 0.12	−5.80	<0.0001	−0.80 ± 0.13	−6.21	<0.0001
Distance to camera	−0.67 ± 0.10	−6.86	<0.0001	−0.61 ± 0.02	−26.84	<0.0001	−0.25 ± 0.02	−10.52	<0.0001
Active - Yes	−0.42 ± 0.26	−1.65	0.10	−0.11 ± 0.06	−1.85	0.065	−0.30 ± 0.06	−4.79	<0.0001
Cage pecking - Yes	−0.04 ± 0.39	−0.10	0.92	−0.05 ± 0.09	−0.59	0.56	0.19 ± 0.10	1.99	0.047
Food-oriented – Hoppers	0.06 ± 0.33	0.18	0.85	0.24 ± 0.08	3.18	0.0015	0.93 ± 0.08	11.61	<0.0001
Food-oriented – Litter	−0.41 ± 0.34	−1.21	0.23	−0.14 ± 0.08	−1.81	0.071	0.46 ± 0.08	5.58	<0.0001
Looking – Yes	−0.42 ± 0.23	−1.87	0.062	−0.17 ± 0.05	−3.22	0.001	−0.04 ± 0.06	−0.74	0.46
Head angle – Down	0.44 ± 0.29	1.53	0.13	−0.12 ± 0.07	−1.82	0.069	0.08 ± 0.07	1.12	0.26
Head position – Up	−0.07 ± 0.38	−0.19	0.85	−0.14 ± 0.09	−1.52	0.13	−0.18 ± 0.09	−1.94	0.053
Head tilt - Side on	−0.69 ± 0.32	−2.14	0.032	0.49 ± 0.08	6.54	<0.0001	0.04 ± 0.08	0.45	0.66
Head tilt – Away	−0.46 ± 0.65	−0.72	0.47	0.30 ± 0.15	1.96	0.050	−0.07 ± 0.16	−0.43	0.66
Side – Right	−0.34 ± 0.19	−1.79	0.073	−0.04 ± 0.04	−0.80	0.43	−0.14 ± 0.05	−2.91	0.0037
Clock Time (min from midnight)	0.01 ± 0.00	2.07	0.038	0.00 ± 0.00	4.91	<0.0001	0.00 ± 0.00	5.00	<0.0001
Body mass (g)	3.36 ± 2.52	1.34	0.18	−0.22 ± 0.40	−0.54	0.59	0.32 ± 0.46	0.68	0.50
Air Temperature (°C)	0.68 ± 1.21	0.56	0.58	−1.33 ± 0.28	−4.77	<0.0001	−1.35 ± 0.30	−4.55	<0.0001
Comb size	0.00 ± 0.00	0.26	0.80	−0.00 ± 0.00	−0.07	0.94	0.00 ± 0.00	0.05	0.96
Phase x Treatment	2.27 ± 0.39	5.81	<0.0001	0.41 ± 0.09	4.48	<0.0001	0.44 ± 0.10	4.49	<0.0001