Table 4.

Breast, fatpad, liver, heart, gastrointestinal tract (GIT), ovary, and oviduct weight as percentage of live BW, and number of large yellow follicles (LYF) of hens at 55 wk fed to achieve a High or Standard BW¹ curve and reared to week 21 on an 8L:16D, 10L:14D, or 12L:12D photoschedule (RPS) and that either commenced egg production (laid) or did not commence egg production (not laid) before week 55.²

	BW	RPS	Breast (%)	SEM	Fatpad (%)	SEM	Liver (%)	SEM	Heart (%)	SEM	GIT (%)	SEM	Ovary (%)	SEM	Oviduct (%)	SEM	LYF	SEM
BW	High		25.8b	0.64	2.4a	0.26	1.7a	0.09	0.36	0.017	4.8	0.15	1.6a	0.22	0.9	0.12	4.4a	0.47
	Standard		27.5a	0.48	1.5b	0.19	1.6b	0.07	0.34	0.013	4.9	0.11	0.9b	0.17	0.9	0.09	2.9b	0.37
RPS		8L:16D	26.1	0.68	2.1	0.27	1.9a	0.09	0.38a	0.018	5.0	0.15	1.3	0.24	0.9	0.13	3.8	0.49
		10L:14D	27.2	0.62	1.7	0.25	1.7b	0.08	0.35a,b	0.016	4.8	0.14	1.1	0.22	0.9	0.11	3.9	0.46
		12L:12D	26.6	0.58	2.1	0.23	1.4c	0.08	0.32b	0.015	4.7	0.13	1.3	0.20	0.9	0.11	3.3	0.44
BW × RPS	High	8L:16D	25.6	0.85	2.5	0.34	2.0	0.12	0.39	0.022	5.0	0.19	1.6	0.30	0.9	0.16	4.7	0.61
		10L:14D	26.6	0.85	2.2	0.34	1.7	0.12	0.37	0.022	4.7	0.19	1.4	0.30	0.9	0.16	4.8	0.61
		12L:12D	25.3	0.85	2.7	0.34	1.4	0.12	0.32	0.022	4.7	0.19	1.8	0.30	0.9	0.16	3.8	0.61
	Standard	8L:16D	26.6	0.82	1.6	0.33	1.8	0.11	0.38	0.021	5.1	0.19	1.1	0.29	0.8	0.15	3.0	0.57
		10L:14D	27.9	0.73	1.3	0.29	1.6	0.10	0.34	0.019	5.0	0.17	0.7	0.26	0.9	0.14	3.1	0.55
		12L:12D	28.0	0.70	1.5	0.28	1.3	0.10	0.32	0.018	4.6	0.16	0.8	0.25	1.0	0.13	2.7	0.53
Laid			24.8b	0.30	2.4a	0.12	1.8a	0.04	0.36	0.008	4.7	0.07	1.8a	0.11	1.6a	0.06	5.6a	0.21
Not laid			28.5a	0.93	1.5b	0.37	1.5b	0.13	0.34	0.024	5.0	0.21	0.7b	0.32	0.2b	0.17	1.8b	0.72
Source of variation			–––––––––––––––––––––––––––––––––––––––––––––––– P-value –––––––––––––––––––––––––––––––––––––––––––––––––––
BW			0.006		<0.001		0.044		0.379		0.587		0.001		0.912		0.001
RPS			0.253		0.347		<0.001		0.002		0.064		0.556		0.930		0.323
BW × RPS			0.423		0.703		0.768		0.608		0.396		0.633		0.717		0.774
Laid			<0.001		0.036		0.005		0.347		0.274		0.004		<0.001		<0.001

^a–cLSMeans within a column and treatment group lacking a common superscript differ (P ≤ 0.05).

¹Hens followed either the breeder-recommended BW curve (Standard) or an accelerated BW curve reaching the 21 wk BW at 18 wk (High).

² The effect of whether hens had commenced egg production or not before week 55 on body composition did not depend on rearing photoschedule.