Table 2.
Egg quality of high- and low-productivity hens

Item	HEP	PEP	SEM1	P-values
Haugh units	80.01	80.05	0.51	0.861
Albumin height (mm)	6.74	6.81	0.06	0.620
Egg shell color	29.53a	25.76b	0.81	0.008
Egg yolk color	5.76b	7.03a	0.26	0.016
Egg shell breaking strength (kgf)	3.42b	4.07a	0.15	0.001
Egg shell thickness (mm)	0.42b	0.45a	0.007	0.005
Egg shell weight (g)	6.92b	7.57a	0.13	<0.001

SEM, standard error of the mean.
Means in same rows with different superscripts are significantly different (P<0.05).
HEP, layers with a laying rate of over 80%; PEP, layers with a laying rate of below 50%.