Table 7.

Effects of dietary treatment on antioxidant capacity in 7- and 14-day-old broilers.

Items	GML levels (mg/kg feed)					SEM	P-value
	CON	300	600	900	1200		Linear	Quadratic
Serum, 7 d of age
MDA (nmol/ml)	5.88	5.29	5.99	5.67	5.08	0.19	0.353	0.506
SOD (U/ml)	67.41b	71.9ab	65.4b	82.87ab	93.84a	3.84	0.196	0.009
T-AOC (mmol/ml)	0.56	0.54	0.57	0.58	0.63	0.02	0.143	0.449
Serum, 14 d of age
MDA (nmol/ml)	6.55a	4.64b	4.07b	4.51b	4.95b	0.22	0.012	0.001
SOD (U/ml)	75.48b	84.33ab	89.43ab	101.29ab	116.44a	4.31	0.001	0.534
T-AOC (mmol/ml)	0.41b	0.47ab	0.49ab	0.52a	0.52a	0.01	0.002	0.272
Jejunum, 7 d of age
MDA (nmol/mgprot)	0.41	0.49	0.52	0.44	0.57	0.03	0.206	0.955
SOD (U/mgprot)	2.62c	3.35bc	3.84ab	3.6ab	4.23a	0.12	<0.001	0.225
T-AOC (mmol/mgprot)	0.08b	0.11ab	0.13ab	0.12ab	0.18a	0.01	0.010	0.898
Jejunum, 14 d of age
MDA (nmol/mgprot)	0.85a	0.6ab	0.56b	0.55b	0.56b	0.03	0.004	0.025
SOD (U/mgprot)	3.72	3.77	3.76	4.01	3.50	0.11	0.855	0.399
T-AOC (mmol/mgprot)	0.09	0.08	0.08	0.08	0.07	0.01	0.335	0.678

MDA, malondialdehyde; SOD, superoxide dismutase; T-AOC, total antioxidant capacity; mgprot, mg of protein; SEM, total standard error of mean.

Values were expressed as least squares means ± SEM (n = 12).

^a,b,cDifferent superscripts in the same line indicate significant differences according to Tukey’s multiple comparisons (P < 0.05).