Table 3.

Effect of dietary natural astaxanthin level on quality of eggs stored at 4°C.¹

Item	Natural astaxanthin (mg/kg)					SEM	P-value
	0	20	40	80	160		ANOVA	Linear	Quadratic
Yolk index	0.46	0.46	0.47	0.47	0.48	0.003	0.457	0.080	0.496
Yolk color	9.61d	12.37c	13.50b	14.66a	14.98a	0.168	<0.001	<0.001	<0.001
Yolk pH	6.28	6.29	6.29	6.28	6.28	0.017	1.000	0.958	0.925
Weight loss (%)	1.86	1.90	1.83	1.89	1.86	0.090	0.999	0.991	0.986
Haugh unit	78.11	78.31	79.03	78.53	81.01	0.442	0.226	0.054	0.366
Eggshell strength (N/cm2)	41.06	40.32	41.78	40.58	41.86	0.299	0.373	0.383	0.577

^a–dMean values within a row without common superscripts differ significantly (P < 0.05).

¹Data were analyzed by 1-way ANOVA with orthogonal linear and quadratic contrasts.