Table 5 Heat stress-related variables, oxidative stress variables, and hypoxia variables in coccygeal vein of dairy cows during different heat stress

NO, μmol/L

5.43

7.19

6.78

0.74

0.32

0.28

0.28

iNOS, U/mL

15.0^a

13.4^b

12.3^b

0.31

 < 0.01

 < 0.01

0.42

eNOS, ng/mL

5.00

4.67

4.91

0.21

0.50

0.77

0.26

HO-1, ng/mL

17.7^b

18.6^b

23.4^a

0.93

 < 0.01

 < 0.01

0.09

VEGF, ng/L

263^b

262^b

313^a

10.4

 < 0.01

 < 0.01

0.02

MDA, nmol/mL

1.29^b

1.40^b

2.18^a

0.17

 < 0.01

 < 0.01

0.07

SOD, U/mL

171^a

167^a

152^b

4.1

 < 0.01

 < 0.01

0.08

GSH-Px, U/mL

40.9^b

55.9^a

42.1^b

2.09

 < 0.01

0.71

 < 0.01

T-AOC, mmol/L

0.32

0.34

0.31

0.01

0.04

0.34

0.02

HSF, ng/L

252

244

282

12.6

0.06

0.07

0.11

HIF-1α, ng/L

207^b

206^b

255^a

10.9

 < 0.01

 < 0.01

0.01

HSP27, ng/mL

4.38^ab

3.88^b

4.46^a

0.17

0.02

0.70

0.01

HSP70, ng/mL

5.12^b

4.83^b

6.21^a

0.24

 < 0.01

 < 0.01

 < 0.01

HSP90, ng/mL

19.2^b

19.6^b

22.8^a

0.76

 < 0.01

 < 0.01

0.06

Total bilirubin, μmol/L

2.31^b

2.06^b

3.83^a

0.12

 < 0.01

 < 0.01

 < 0.01