Table 6.

Effect of dietary natural astaxanthin levels on quality of eggs stored at 25°C.¹

Item	Natural astaxanthin (mg/kg)					SEM	P-value
	0	20	40	80	160		ANOVA	Linear	Quadratic
Yolk index	0.28	0.28	0.29	0.29	0.30	0.011	0.990	0.606	0.990
Yolk color	10.24d	12.28c	13.56b	14.71a	15.96a	0.205	<0.001	<0.001	<0.001
Yolk pH	6.54	6.48	6.49	-∗	-∗	0.038	0.813	0.607	0.709
Weight loss (%)	6.92	6.78	6.85	6.72	6.82	0.508	1.000	0.944	0.950
Haugh unit	56.92	59.75	60.10	58.23	62.30	2.145	0.953	0.522	0.989
Eggshell strength (N/cm2)	41.95	41.86	42.20	42.29	42.03	0.288	0.990	0.776	0.809

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

∗Not determined because the Haugh unit was very low (<25) and yolk breakage.

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