Table 7.

Effect of dietary Met:Lys ratio in the lactation diet on oxidative stress parameters of sows

Items	Met:Lys				SEM	P-value
	0.27	0.37	0.47	0.57		Linear	Quadratic	Feed
No. of sows1
At parturition
GSH-Px, U/mL3	843.73	800.09	768.65	811.04	16.33	0.38	0.28	0.44
T-AOC, U/mL3	0.77	0.59	0.98	0.95	0.06	0.07	0.44	0.08
ROS, U/mL	36.49	30.83	41.48	41.65	2.27	0.44	0.62	0.30
8-OHdG, ng/mL	37.44	33.07	37.72	33.26	1.83	0.66	0.91	0.70
TBARS, nmol/mL	3.08	3.1	2.81	2.71	0.16	0.35	0.60	0.79
At day 7
GSH-Px, U/mL2,3	672.88B	811.65A	763.09A	621.40B	16.91	0.19	0.00	0.00
T-AOC, U/mL2,3	0.30C	0.58B	1.00A	0.50BC	0.06	0.04	0.00	0.00
ROS, U/mL	34.66	32.54	39.11	38.22	1.87	0.21	0.41	0.12
8-OHdG, ng/mL2	50.05a	43.08ab	38.47b	38.78b	1.60	0.01	0.01	0.03
TBARS, nmol/mL2	3.82b	3.78b	4.51ab	4.73a	0.15	0.01	0.02	0.04
At weaning
GSH-Px, U/mL2,3	632.84C	895.69A	773.88B	799.85B	17.92	0.03	0.00	0.00
T-AOC, U/mL2,3	0.36B	0.62B	1.27A	1.36A	0.10	0.00	0.00	0.00
ROS, U/mL	46.20	37.92	39.79	40.64	1.79	0.64	0.54	0.45
8-OHdG, ng/mL2	50.56a	40.58b	49.15a	50.42a	1.37	0.58	0.31	0.02
TBARS, nmol/mL	2.47	2.24	2.67	3.65	0.19	0.03	0.02	0.17

¹The number of samples of sows in each group was more than 9 but not equal; SEM, standard error of the mean;

²Means in the same row with different letters differ significantly; the different lowercase letters represent P < 0.05, and the different capital letters represent P < 0.01;

³There was a treatment × sampling day interaction for plasma GSH-Px and T-AOC concentrations (P < 0.01), and the levels of GSH-Px and T-AOC in plasma at parturition and weaning were significantly higher than those at day 7 (P < 0.001);

GSH-Px glutathione peroxidase, T-AOC total antioxidant capacity, ROS reactive oxygen species; 8-OHdG 8-hydroxy-deoxyguanosine; TBARS thiobarbituric acid reactive substances