Table 5.

Effects of dietary Moutan cortex radicis on serum antioxidant indexes in growing pigs.

Items2	Diets1				P-value	Regression analysis
	CON	LMC	MMC	HMC		Liner effect	Quadratic effect
T-AOC, U/mL	1.96 ± 0.20a	1.85 ± 0.08a	3.28 ± 0.25b	3.72 ± 0.26b	<0.01	0.682	0.671
CAT, U/mL	23.06 ± 2.45a	38.94 ± 3.89bc	32.42 ± 2.92ab	54.47 ± 5.06c	<0.01	0.834	0.927
SOD, U/mL	40.44 ± 1.88	48.94 ± 1.68	50.50 ± 4.87	52.22 ± 5.25	0.184	0.796	0.826
GSH-Px, U/mL	1238.78 ± 39.91b	933.63 ± 52.70a	946.55 ± 89.92a	934.80 ± 54.35a	<0.01	0.145	0.122
MDA, nmol/mL	10.35 ± 2.22b	5.11 ± 0.70a	2.81 ± 0.55a	2.53 ± 0.29a	<0.01	0.03	0.069

¹CON, control group, basal diet without antibiotics; LMC, the control diet + 2,000 mg/kg Moutan cortex radicis; MMC, the control diet + 4,000 mg/kg Moutan cortex radicis; HMC, the control diet + 8,000 mg/kg Moutan cortex radicis.

²T-AOC, total antioxidant capacity; CAT, catalase; SOD, superoxide dismutase; GSH-Px, glutathione peroxidase; MDA, malondialdehyde.

Data are expressed as means ± SEM (n = 8). Means within a row with different superscripts are significantly different (P < 0.05).