Table 5.
Mean ruminal pH, ammonia-N (mg/L), total volatile fatty acid (VFA) concentrations mmol/L), and individual VFA molar proportions (%) in Merino sheep fed pelleted diets containing varying levels of (industrial) hemp stubble
| Parameter | Diet | P value | ||
|---|---|---|---|---|
| Control (0% hemp stubble) | Hemp 1 (28% hemp stubble) | Hemp 2 (56% hemp stubble) | ||
| Rumen pH | 6.87 (± 0.112) | 6.89 (± 0.105) | 6.84 (± 0.123) | 0.9446 |
| Ammonia-N | 154 (± 34.4) | 270 (± 34.4) | 270 (± 34.4) | 0.0558 |
| Total VFA | 69.10 (± 3.158) | 79.89 (± 3.158) | 76.28 (± 3.158) | 0.0651 |
| Acetic acid | 63.15 (± 1.194) | 62.39 (± 1.143) | 63.85 (± 1.278) | 0.6310 |
| Propionic acid | 24.19 (± 1.135) | 22.03 (± 1.135) | 20.69 (± 1.135) | 0.1087 |
| Butyric acid | 11.62 (± 0.566) | 13.20 (± 0.566) | 12.84 (± 0.566) | 0.1352 |
| Iso-butyric acid | 0.30 (± 0.028)b | 0.57 (± 0.028)a | 0.65 (± 0.028)a | <0.0001 |
| Valeric acid | 0.62 (± 0.081)b | 0.97 (± 0.074)a | 1.12 (± 0.093)a | <0.0001 |
| Iso-valeric acid | 0.51 (± 0.095)b | 0.97 (± 0.085)a | 1.20 (± 0.110)a | <0.0001 |
| Hexanoic acid | 0.07 (± 0.034)b | 0.22 (± 0.034)a | 0.24 (± 0.034)a | 0.0025 |
| Heptanoic acid | 0.001 (± 0.0035)b | 0.014 (± 0.0035)a | 0.011 (± 0.0035)a | 0.0247 |
| Pr:Ac 2 × Bua | 0.28 (± 0.017) | 0.25 (± 0.017) | 0.24 (± 0.017) | 0.1233 |
| Acetic:propionic | 2.74 (± 0.263) | 2.90 (± 0.251) | 3.38 (± 0.282) | 0.1524 |
Values are least squares means ± standard errors of the least squares means.
a Pr:Ac 2 × Bu = ratio of propionic acid to acetic acid + 2 × butyric acid.
Different superscripts within rows for each parameter indicates that there is a significant difference (P ≤ 0.05).