Table 2.
Effect of sulfur and urea levels on feed intake and nutrient digestibility in dairy cows.
| Items | Sulfur-1 | Sulfur-2 | SEM | P value | ||||
|---|---|---|---|---|---|---|---|---|
| Urea-1 | Urea-2 | Urea-1 | Urea-2 | Sulfur | Urea | Sulfur ∗ urea | ||
| RS intake | ||||||||
| kg DM/d | 3.75 | 3.85 | 3.82 | 3.87 | 0.035 | 0.488 | 0.305 | 0.727 |
| % BW | 0.83 | 0.85 | 0.85 | 0.86 | 0.007 | 0.412 | 0.222 | 0.683 |
| g/kg BW0.75 | 38.25 | 39.28 | 39.02 | 39.54 | 0.277 | 0.372 | 0.186 | 0.655 |
|
| ||||||||
| Concentrate intake | ||||||||
| kg DM/d | 5.62 | 5.62 | 5.62 | 5.62 | 0.130 | 1.000 | 1.000 | 1.000 |
| % BW | 1.24 | 1.24 | 1.24 | 1.24 | 0.024 | 0.979 | 0.996 | 0.985 |
| g/kg BW0.75 | 57.34 | 57.32 | 57.36 | 57.40 | 1.139 | 0.982 | 0.997 | 0.989 |
| Fresh cassava root intake, kg DM/d | 6.82 | 6.82 | 6.82 | 6.82 | 0.062 | 1.000 | 1.000 | 1.000 |
| HCN intake, mg/d | 713.89 | 713.89 | 713.89 | 713.89 | 6.537 | 1.000 | 1.000 | 1.000 |
| Urea intake, g/d | 56.25 | 56.25 | 112.50 | 112.50 | 1.960 | <.0001 | 1.000 | 1.000 |
|
| ||||||||
| Sulfur intake | ||||||||
| g/d | 56.25 | 56.25 | 112.50 | 112.50 | 1.960 | <.0001 | 1.000 | 1.000 |
|
| ||||||||
| Total DM intake | ||||||||
| kg DM/d | 16.20 | 16.30 | 16.27 | 16.32 | 0.197 | 0.901 | 0.852 | 0.950 |
| % BW | 3.58 | 3.60 | 3.60 | 3.61 | 0.026 | 0.811 | 0.746 | 0.931 |
| g/kg BW0.75 | 165.21 | 166.22 | 166.00 | 166.56 | 1.283 | 0.829 | 0.765 | 0.932 |
|
| ||||||||
| Digestibility | ||||||||
| DM, g/kg | 652.3a | 662.1a | 685.1b | 686.3b | 1.02 | 0.013 | 0.078 | 0.064 |
| OM, g/kg DM | 698.4a | 700.5a | 712.4b | 715.6b | 1.12 | 0.034 | 0.094 | 0.087 |
| CP, g/kg DM | 616.5a | 621.7b | 613.7a | 631.3b | 0.160 | 0.309 | 0.004 | 0.076 |
| NDF, g/kg DM | 594.2 | 596.1 | 598.0 | 596.4 | 2.40 | 0.094 | 0.085 | 0.095 |
| ADF, g/kg DM | 385.4 | 392.5 | 394.5 | 387.6 | 1.58 | 0.092 | 0.124 | 0.093 |
Sulfur-1 and sulfur-2 = sulfur addition into concentrates at 10 g/kg DM and 20 g/kg DM. Urea-1 and urea-2 = urea addition into concentrates at 10 g/kg DM and 20 g/kg DM; SEM = standard error of mean; BW = body weight; BW0.75 = metabolic body weight; DM = dry matter; OM = organic matter; CP = crude protein; NDF = neutral detergent fiber; ADF = acid detergent fiber; sulfur ∗ urea = interaction effect between sulfur and urea; a, bmeans in the same row with different superscript letters are accepted as significantly different (p < 0.05).