Table 4.

Effects of dietary marigold extract on the antioxidant capacity of liver and thigh muscle in broiler chickens

Items	The level of marigold extract (%)					SEM	p value	Contrast
	0	0.075	0.15	0.30	0.60			Linear	Quadratic
Liver
T-AOC (U/mg of protein)	1.8c	2.2b	2.3b	3.2a	3.1a	0.10	<0.001	<0.001	0.721
SOD (U/mg of protein)	289.7c	329.9bc	337.5b	337.5b	398.3a	8.37	<0.001	<0.001	0.547
GSH-PX (U/mg of protein)	43.4c	48.6b	49.2b	52.7ab	57.6a	1.07	<0.001	<0.001	0.731
MDA (nmol/mg of protein)	1.8a	1.8a	1.6a	1.6a	1.2b	0.07	0.011	0.001	0.172
Muscle
T-AOC (U/mg of protein)	0.2b	0.2b	0.3ab	0.3a	0.3a	0.01	0.027	0.002	0.639
SOD (U/mg of protein)	20.3c	25.8b	25.4b	27.5b	35.9a	1.07	<0.001	<0.001	0.190
GSH-PX (U/mg of protein)	8.1	8.5	9.6	9.6	11.2	0.55	0.441	0.070	0.773
MDA (nmol/mg of protein)	1.2a	0.8b	0.9b	0.7b	0.7b	0.04	<0.001	<0.001	0.021

SEM, standard error of the means; T-AOC, total antioxidant capacity; SOD, superoxide dismutase; GSH-PX, glutathione peroxidase; MDA, malondialdehyde.

^a,b,cMeans within the same row with no common superscript differ significantly (p<0.05). n = 8.