Table 2.
Effect of supplementing chitosan on milk yield and composition, and methane production.
| HF | BS | p-Value | ||||||
|---|---|---|---|---|---|---|---|---|
| CTR | CHI | CTR | CHI | SEM | Breed | Treat | Breed × Treat | |
| Yield, kg/d | ||||||||
| Milk | 25.8 | 26.2 | 26.0 | 27.3 | 1.52 | 0.718 | 0.562 | 0.756 |
| ECM | 26.7 | 24.0 | 28.3 | 29.3 | 2.25 | 0.160 | 0.709 | 0.406 |
| Fat | 1.22 | 0.757 | 1.13 | 1.16 | 0.1536 | 0.355 | 0.167 | 0.131 |
| Protein | 1.05 | 0.912 | 0.944 | 0.993 | 0.1048 | 0.921 | 0.664 | 0.365 |
| Lactose | 1.49 | 1.32 | 1.29 | 1.34 | 0.1233 | 0.539 | 0.627 | 0.358 |
| Composition, % | ||||||||
| Fat | 4.68 | 3.61 | 4.09 | 4.00 | 0.306 | 0.742 | 0.080 | 0.130 |
| Protein | 3.54 | 3.54 | 3.65 | 3.62 | 0.094 | 0.882 | 0.358 | 0.883 |
| Lactose | 4.83 | 4.73 | 4.73 | 4.90 | 0.069 | 0.588 | 0.640 | 0.056 |
| CH4 | ||||||||
| ppm | 1605 | 1770 | 2325 | 1924 | 329.2 | 0.271 | 0.727 | 0.461 |
| g/d | 214 | 206 | 290 | 234 | 45.3 | 0.337 | 0.498 | 0.642 |
| g/kg milk | 9.54 | 9.14 | 10.85 | 9.51 | 2.242 | 0.740 | 0.694 | 0.496 |
HF: Holstein Friesian; BS: brown Swiss; CTR: control; CHI: chitosan; SEM: standard error of the mean; Treat: treatment, and ECM: energy corrected milk.