Table 3.
Chemical composition (mean ± SD) and trace minerals of the control (free of supplemental Mn, Zn and Cu) and mineral-supplemented diets fed to the cows before or after calving.
| Item | Feeding phase1 |
|||
|---|---|---|---|---|
| Far-off | Close-up | Fresh | Lactation | |
| Chemical composition, g/kg DM2 | ||||
| Crude protein | 110 ± 3.13 | 137 ± 4.99 | 178 ± 6.30 | 169 ± 5.86 |
| Organic matter | 926 ± 6.31 | 906 ± 6.45 | 920 ± 7.57 | 909 ± 7.29 |
| Neutral detergent fibre | 475 ± 5.00 | 329 ± 5.60 | 285 ± 4.28 | 319 ± 6.91 |
| Ether extract | 25.6 ± 0.30 | 29.0 ± 0.83 | 36.5 ± 0.61 | 44.8 ± 0.98 |
| NEL, Mcal/kg DM | 1.27 ± 0.03 | 1.57 ± 0.02 | 1.85 ± 0.04 | 1.64 ± 0.03 |
| Mn, mg/kg DM | ||||
| Control diet | 20.0 | 22.9 | 23.6 | 21.9 |
| Mineral-sulphate diet3 | 35.1 | 38.0 | 35.6 | 28.0 |
| Mineral-glycine diet3 | 35.6 | 37.7 | 35.5 | 27.5 |
| Mineral-methionine diet3 | 35.3 | 37.7 | 35.9 | 27.5 |
| Zn, mg/kg DM | ||||
| Control diet | 20.1 | 24.4 | 28.7 | 27.2 |
| Mineral-sulphate diet3 | 44.3 | 45.2 | 126 | 101 |
| Mineral-glycine diet3 | 44.8 | 45.0 | 122 | 102 |
| Mineral-methionine diet3 | 44.6 | 45.5 | 128 | 104 |
| Cu, mg/kg DM | ||||
| Control diet | 5.48 | 5.98 | 7.30 | 8.72 |
| Mineral-sulphate diet3 | 26.8 | 26.7 | 26.9 | 22.3 |
| Mineral-glycine diet3 | 26.7 | 27.0 | 26.4 | 22.7 |
| Mineral-methionine diet3 | 26.5 | 26.5 | 26.3 | 22.2 |
NEL = net energy for lactation.
1
Far-off: d 60 to 22 prepartum; close-up: d 21 to 1 prepartum; fresh: d 1 to 21 postpartum; lactation: d 22 to 100 postpartum.
2
The chemical composition and trace minerals of the diets were determined using the standard chemical procedures, as described in the Materials and methods section.
3
The trace mineral-supplemented diets contained Mn as MnSO4·H2O, Mn-methionine or Mn-glycine, Zn as ZnSO4·2H2O, Zn-methionine or Zn-glycine, and Cu as CuSO4·7H2O, Cu-methionine or Cu-glycine.