Table 4.
Effects of xylooligosaccharides (XOS), exogenous enzyme (EXE) and their combinations on gas production and methane emission intensities in lactating Jersey cows
| Item | CON1 | XOS | EXE | XOS + EXE | P-value |
|---|---|---|---|---|---|
| CH4, g/d | 399.8 ± 22.79a | 364.1 ± 31.42b | 374.9 ± 26.81b | 371.3 ± 32.20b | 0.03 |
| CO2 production, g/d | 7,624 ± 1,665.2c | 9,055 ± 1,797.6b | 10,104 ± 1,982.5a | 11,042 ± 2,009.2a | 0.03 |
| O2 consumption, g/d | 7,242 ± 1,558.0c | 8,905 ± 1,667.8b | 9,330 ± 1,792.9a | 10,884 ± 1,299.4a | < 0.01 |
| CH4/DM intake, g/kg | 22.8 ± 1.96a | 20.3 ± 2.21b | 21.2 ± 3.57b | 21.3 ± 2.19b | < 0.01 |
| CH4/Milk yield, g/kg | 21.7 ± 2.20a | 18.6 ± 3.11c | 19.9 ± 3.52b | 19.1 ± 2.69b | 0.03 |
| CH4/ECM, g/kg | 17.8 ± 1.05a | 14.8 ± 1.77c | 16.0 ± 2.10b | 16.0 ± 2.51b | < 0.01 |
| RQmetab 2 | 0.58 ± 0.012 | 0.60 ± 0.09 | 0.65 ± 0.013 | 0.62 ± 0.014 | 0.07 |
1CON Control (no feed additives), XOS 25 g/d per cow, EXO 15 g/d per cow, and XOS + EXE Combination of XOS and EXE. Data are given as mean ± standard error of means
2RQmetab = metabolic respiratory quotient, calculated as metabolic CO2 production/O2 consumption on a volume basis according to Derno et al. [32]
a–c Means within a row with different superscripts are significantly different (P < 0.05)