Table 3.

Effects of MCE on egg quality of Xuefeng black-bone chicken.¹

Item	Groups (MCE mg/kg)				SEM	P-value
	0	100	150	200
Week 8
Eggshell strength (N/m2)	3.53	3.78	3.64	3.93	0.10	0.483
Egg weight (g)	54.79	51.81	53.14	53.28	0.56	0.322
Haugh unit	61.62	63.22	60.72	62.46	1.16	0.896
Yolk index	0.43	0.42	0.44	0.46	0.01	0.080
Eggshell thickness (mm)	0.33b	0.33b	0.34a,b	0.35a	0.01	0.019
Week 12
Eggshell strength (N/m2)	3.36b	3.63b	4.06a	3.68a,b	0.08	0.011
Egg weight (g)	52.67	52.04	51.67	53.08	0.43	0.667
Haugh unit	62.21	58.93	60.05	60.11	0.75	0.498
Yolk index	0.37	0.37	0.38	0.38	0.01	0.319
Eggshell thickness (mm)	0.31B	0.33A	0.33A	0.33A	0.01	0.006

^a,bMeans within a row with different superscripts for each factor are significantly different (P < 0.05).

^A,BMeans within a row with no common superscripts indicate a highly significant difference (P < 0.01).

Abbreviation: MCE, Macleaya cordata extract.

¹Group means were represented as the mean of the corresponding data from 6 replicates (4 eggs per replicate).