TABLE 4.

Effect of dietary Bopu powder supplementation on serum antioxidant capacity of laying hens.

Item	Bopu powder, mg/kg						SEM	p value
	0	25	50	100	200	400		ANOVA	Linear	Quadratic
T-AOC, mmol/L	1.10	1.21	1.20	1.40	1.20	1.33	0.040	0.362	0.238	0.407
T-SOD, U/ml	722.32	682.78	703.92	712.93	736.85	649.18	12.94	0.475	0.238	0.172
GSH-Px, U/ml	175.86a	219.36 ab	240.00b	257.49b	227.52 ab	256.12b	88.17	0.042	0.062	0.086
GSH, umol/L	40.11	44.23	41.80	40.71	44.43	45.51	1.034	0.634	0.170	0.403
CAT, U/ml	3.8b	8.0a	7.9a	7.6a	8.8a	8.1a	0.110	0.001	0.032	0.585
MAD, nmol/ml	8.66	8.33	7.50	8.26	8.15	6.79	0.804	0.993	0.557	0.837

^a,bMeans in the same row with different superscript letters indicate differences (p < 0.05).

T-AOC, total antioxidative capacity; T-SOD, total superoxide dismutase; GSH-Px, glutathione peroxidase; GSH, glutathione; CAT, catalase; MAD, malondialdehyde.