Table 3.

Effects of different zinc sources on plasma variables in lactating dairy cows.

Item	Treatment			SEM	P-value
	Control	Zinc-Met	Nano-sized zinc		Treat	Week	Treat × week
Zinc, mg/L	1.21c	1.25b	1.29a	0.012	<0.01	0.44	0.31
MDA, nmol/mL	2.66	2.57	2.66	0.096	0.75	0.83	0.66
SOD, U/mL	107.3	107.6	111.9	2.71	0.40	0.75	0.45
GSH-Px, U/mL	128.6	124.6	125.9	3.05	0.62	0.10	0.88
T-AOC, U/mL	3.76	3.88	3.98	0.115	0.39	0.60	0.84
Lactose, μmol/L	113.4	113.2	109.9	1.93	0.35	0.41	0.78

MDA = malondialdehyde; SOD = superoxide dismutase; GSH-Px = glutathione peroxidase; T-AOC = total antioxidant capacity.

^{a, b, c} Within a row, values with a different superscript suggested a statistical difference across the different treatment groups.