Table 3.

Effects of dietary Se sources on egg quality of laying hens.

Itemsa	Ctrl	Norm	SS	SEY	SEIP	SEM	P-value
Week 6
Albumen ratio, %	64.70	64.90	64.59	64.91	64.29	0.28	0.52
Yolk ratio, %	24.48	24.24	24.58	24.48	24.92	0.25	0.45
Shell ratio, %	10.82	10.87	10.83	10.62	10.79	0.17	0.85
Egg shape index	1.33	1.32	1.31	1.31	1.32	0.01	0.19
Shell thickness, mm	0.455	0.447	0.448	0.453	0.453	0.01	0.90
Shell stiffness, N/mm	77.16	78.62	78.43	79.10	79.00	0.57	0.15
Shell strength, N	45.59	46.23	45.84	46.41	45.87	0.90	0.97
Albumen height, mm	7.46	7.73	7.14	7.61	7.50	0.20	0.32
Yolk color	5.58	5.63	5.53	5.43	5.43	0.15	0.84
Haugh units	86.11	87.77	83.89	87.04	86.8	1.22	0.24
Week 12
Albumen ratio, %	64.39	64.82	64.44	64.88	64.43	0.39	0.83
Yolk ratio, %	25.33	24.82	25.25	24.76	25.36	0.36	0.64
Shell ratio, %	10.28	10.36	10.32	10.36	10.21	0.11	0.85
Egg shape index	1.32	1.31	1.32	1.31	1.32	0.01	0.39
Shell thickness, mm	0.455	0.443	0.442	0.455	0.455	0.01	0.40
Shell stiffness, N/mm	77.81	75.62	77.45	78.93	78.61	1.92	0.77
Shell strength, N	44.45	42.95	44.13	45.54	46.02	1.08	0.31
Albumen height, mm	7.39	7.75	7.51	7.67	7.91	0.15	0.15
Yolk color	7.13	7.17	7.27	7.97	7.17	0.31	0.30
Haugh units	86.13	88.04	86.77	87.79	89.17	0.94	0.21

^aData are the mean of eight replicates; SEM, standard error of mean; Ctrl, the birds fed the basal diet; Norm, the birds fed 0.3 mg/kg of Se provided by sodium selenite; SS, SEY, and SEIP, the birds fed 2 mg/kg of Se provided by sodium selenite, Se yeast, and Se-enriched insect protein powder, respectively.