Table 4 Effects of xylooligosaccharides (XOS), exogenous enzyme (EXE) and their combinations on gas production and methane emission intensities in lactating Jersey cows

CH₄, g/d

399.8 ± 22.79^a

364.1 ± 31.42^b

374.9 ± 26.81^b

371.3 ± 32.20^b

0.03

CO₂ production, g/d

7,624 ± 1,665.2^c

9,055 ± 1,797.6^b

10,104 ± 1,982.5^a

11,042 ± 2,009.2^a

0.03

O₂ consumption, g/d

7,242 ± 1,558.0^c

8,905 ± 1,667.8^b

9,330 ± 1,792.9^a

10,884 ± 1,299.4^a

< 0.01

CH₄/DM intake, g/kg

22.8 ± 1.96^a

20.3 ± 2.21^b

21.2 ± 3.57^b

21.3 ± 2.19^b

< 0.01

CH₄/Milk yield, g/kg

21.7 ± 2.20^a

18.6 ± 3.11^c

19.9 ± 3.52^b

19.1 ± 2.69^b

0.03

CH₄/ECM, g/kg

17.8 ± 1.05^a

14.8 ± 1.77^c

16.0 ± 2.10^b

16.0 ± 2.51^b

< 0.01

RQ_metab ²

0.58 ± 0.012

0.60 ± 0.09

0.65 ± 0.013

0.62 ± 0.014

0.07