. 2019 Jul 2;5(3):241–247. doi: 10.1016/j.aninu.2019.06.007

Table 4.

Effects of 2 sources and levels of methionine on the antioxidant property in serum and liver of broilers on d 21.

Source	Level, %	Serum	Liver
Source	Level, %	GPx, U/mL	GPx, U/mg protein	T-GSH, nmol/g	GSSG, nmol/g	GSH, nmol/g	GSH:GSSG
DLM	0.05	1,665.89	30.74	1,733.23^a	428.81^a	875.61	4.10
DLM	0.25	2,639.79	34.96	2,132.34^b	635.82^b	860.70	3.35
HMTBa	0.05	1,699.77	32.47	1,512.09^a	423.15^a	665.79	3.63
HMTBa	0.25	2,457.07	35.63	1,720.89^a	422.82^a	715.79	3.32
SEM		59.22	0.80	63.37	23.94	32.80	0.06
Main effect
Source	DLM	2,152.84	33.35	1,932.79^b	532.32^b	868.15^b	3.73
Source	HMTBa	2,078.42	33.93	1,475.47^a	427.66^a	620.14^a	3.48
Level, %	0.05	1,682.83^a	31.99	1,622.66	425.98^a	770.70	3.86^b
Level, %	0.25	2,548.43^b	35.29	1,785.60	534.00^b	717.60	3.35^a
P-value
Source		0.540	0.724	<0.001	0.002	<0.001	0.079
Level		<0.001	0.054	0.095	0.002	0.332	0.001
Source × Level		0.374	0.955	0.019	0.004	0.484	0.100

GPx = glutathione peroxidase; T-GSH = total glutathione; GSSG = glutathione disulfide; GSH = glutathione; DLM = DL-methionine; HMTBa = DL-2-hydroxy-4-methylthio-butanoic acid.

^{a, b} Within a column, means sharing the same superscripts are not significantly different from each other at P < 0.05.