Table 5. Back-transformed least squares means for associations of underfloor heating and photoperiod regimen with welfare problems detected by transect sampling and production outcomes.

Variable	Underfloor heating										Photoperiod regimen
	Without				With				F1	P	18 h continuous				16 h intermittent				F1	P
	Mean	SE	Lower 95% CL	Upper 95% CL	Mean	SE	Lower 95% CL	Upper 95% CL			Mean	SE	Lower 95% CL	Upper 95% CL	Mean	SE	Lower 95% CL	Upper 95% CL
On-farm welfare assessment indicators
Walking difficulties (%)	0.23	0.03	0.17	0.31	0.29	0.03	0.23	0.37	1.66	0.221	0.27	0.03	0.21	0.35	0.25	0.04	0.18	0.33	0.27	0.616
Illness (%)	0.08	0.01	0.05	0.12	0.05	0.01	0.04	0.07	3.62	0.081	0.09	0.01	0.07	0.12	0.05	0.01	0.03	0.07	8.11	0.015
Skin wounds (%)	0.07	0.02	0.04	0.12	0.06	0.01	0.04	0.09	0.14	0.717	0.10	0.02	0.07	0.14	0.04	0.01	0.03	0.08	6.47	0.026
Small (%)	0.05	0.02	0.02	0.10	0.10	0.03	0.05	0.17	2.22	0.162	0.08	0.02	0.04	0.14	0.06	0.02	0.03	0.13	0.18	0.678
Welfare problems index (%)	0.44	0.07	0.32	0.62	0.51	0.06	0.40	0.70	0.55	0.472	0.57	0.07	0.44	0.74	0.40	0.06	0.29	0.56	3.10	0.104
Litter score	1.34	0.16	1.02	1.75	1.08	0.11	0.87	1.34	1.72	0.214	1.13	0.11	0.91	1.41	1.27	0.16	0.97	1.66	0.44	0.518
Production outcomes
Mortality (%)	3.22	0.51	2.29	4.53	2.86	0.37	2.17	3.77	0.33	0.578	3.98	0.50	3.03	5.23	2.31	0.37	1.63	3.26	6.71	0.022
Rejection due to perosis (%)	0.01	<0.01	0.01	0.02	<0.01	<0.01	<0.01	0.01	5.41	0.037	0.01	<0.01	<0.01	0.01	0.01	<0.01	<0.01	0.01	0.15	0.709
Rejection due to illness (%)	1.34	0.21	0.96	1.87	0.98	0.12	0.75	1.28	2.33	0.151	1.25	0.16	0.96	1.64	1.05	0.16	0.75	1.46	0.77	0.397
Rejection due to wounds (%)	0.06	0.03	0.02	0.15	0.07	0.03	0.03	0.15	0.12	0.739	0.09	0.03	0.04	0.18	0.05	0.02	0.02	0.13	0.80	0.387
Rejection because underweight (%)	0.08	0.03	0.03	0.19	0.09	0.03	0.04	0.18	0.05	0.823	0.11	0.04	0.05	0.24	0.06	0.03	0.02	0.15	1.37	0.263
Total rejections (%)	1.65	0.26	1.17	2.33	1.35	0.17	1.02	1.78	0.92	0.355	1.79	0.23	1.36	2.35	1.25	0.20	0.88	1.77	2.86	0.115
Footpad score (binary)	0.39	0.17	0.13	0.75	0.38	0.13	0.16	0.68	<0.00	0.962	0.51	0.14	0.24	0.77	0.28	0.15	0.08	0.65	1.02	0.331
Growth rate (g/day)	42.18	0.82	40.44	44.00	43.68	0.69	42.22	45.19	1.80	0.203	42.86	0.68	41.43	44.35	42.99	0.84	41.21	44.84	0.01	0.914
Feed conversion (ratio)	2.27	0.04	2.19	2.35	2.21	0.03	2.14	2.27	1.71	0.214	2.23	0.03	2.16	2.29	2.25	0.04	2.17	2.33	0.18	0.676
Production index (g/day)	39.93	0.81	38.22	41.72	41.54	0.68	40.09	43.04	2.13	0.168	40.19	0.66	38.79	41.64	41.27	0.84	39.50	43.13	0.95	0.346

¹F_{1, 12} for welfare assessment variables; F_{1, 13} for production variables. See Methods and Table 3 footnotes for explanation of variables.