Table 4.

Effects of breeding pigeon dietary supplementation with dl-Met or dl-Met-Met on the antioxidant activity of the breast muscle of squabs^1,2.

Items3	Met Source	Met Dose	CAT (U/mg-prot)	T-SOD (U/mg-prot)	GSH-Px (U/mg-prot)	T-AOC (U/mg-prot)	MDA (nmol/mg-prot)
1	BD	0	0.71d	18.94e	30.57c	0.35	0.86a
2	dl-Met	0.15%	0.77c	23.15d	35.88bc	0.41	0.70b
3	dl-Met	0.30%	0.81abc	28.43ab	38.34ab	0.46	0.59b
4	dl-Met	0.45%	0.81abc	26.68abcd	37.54ab	0.45	0.61b
5	dl-Met	0.60%	0.80abc	25.77bcd	38.01ab	0.44	0.56b
6	dl-Met-Met	0.15%	0.79bc	24.54cd	36.18b	0.41	0.64b
7	dl-Met-Met	0.30%	0.85a	25.77a	42.66a	0.44	0.59b
8	dl-Met-Met	0.45%	0.84ab	27.83abc	39.38ab	0.42	0.64b
9	dl-Met-Met	0.60%	0.84ab	28.20ab	40.51ab	0.44	0.65b
SEM			0.009	0.641	0.765	0.012	0.021
P-values
treatment effects			<0.001	<0.001	0.008	0.604	0.013
Met source			0.032	0.159	0.117	0.636	0.653
main effect of the Met source
dl-Met			0.80b	26.01	37.44	0.44	0.61
dl-Met-Met			0.83a	27.54	39.69	0.43	0.63
linear effect4
dl-Met			0.003	<0.001	0.013	0.111	<0.001
dl-Met-Met			<0.001	<0.001	<0.001	0.068	0.027
quadratic effect4
dl-Met			0.041	0.002	0.083	0.204	0.041
dl-Met-Met			0.003	0.002	0.009	0.276	0.017

¹ Values without the same small letters in the column indicate a significant difference (p < 0.05, n = 8). The data are presented as the mean ± standard error; ² CAT: catalase; T-SOD: total superoxide dismutase; GSH-Px: glutathione peroxidase; T-AOC: total antioxidant capacity; MDA: malonaldehyde; ³ 1: BD; 2: 0.15% dl-Met; 3: 0.30% dl-Met; 4: 0.45% dl-Met; 5: 0.60% dl-Met; 6: 0.15% dl-Met-Met; 7: 0.30% dl-Met-Met; 8: 0.45% dl-Met-Met; 9: 0.60% dl-Met-Met. (BD: basal diet; dl-Met: dl-methionine; dl-Met-Met: dl-methionyl- dl-methionine); ⁴ Trend analysis for BD and BD with 0.15%, 0.30%, 0.45% and 0.60% dl-Met or dl-Met-Met.