Table 2.
Milk composition of lactating cows selected for high or low milk solid.
| Item | HS | LS | SEM | P-value |
|---|---|---|---|---|
| DMI, kg/d | 23.89 | 21.30 | 0.558 | 0.011 |
| CP intake, kg/d | 2.49 | 2.25 | 0.051 | 0.012 |
| NDF intake, kg/d | 13.78 | 12.28 | 0.322 | 0.011 |
| ADF intake, kg/d | 3.87 | 3.41 | 0.100 | 0.010 |
| Milk yield, kg/d | 33.66 | 33.55 | 0.639 | 0.932 |
| TMS yield, kg/d | 4.38 | 3.81 | 0.118 | 0.007 |
| Moisture, % | 86.99 | 88.62 | 0.271 | 0.001 |
| Milk fat, % | 4.41 | 2.77 | 0.269 | 0.000 |
| Milk protein, % | 3.34 | 2.99 | 0.066 | 0.002 |
| Milk fat-to-protein ratio | 1.32 | 0.93 | 0.072 | 0.001 |
| Lactose, % | 4.84 | 4.98 | 0.044 | 0.112 |
| TMS, % | 13.01 | 11.38 | 0.272 | 0.000 |
| Non-fat milk solid, % | 8.60 | 8.61 | 0.077 | 0.976 |
| Percentage to TMS, %rowhead | ||||
| Milk fat | 33.89 | 24.23 | 1.639 | 0.000 |
| Milk protein | 25.66 | 26.32 | 0.367 | 0.398 |
| Lactose | 37.21 | 43.86 | 1.064 | 0.000 |
| Non-fat milk solid | 56.11 | 75.77 | 1.639 | 0.000 |
HS = high total milk solid group; LS = low total milk solid group; SEM = standard error of the mean; DMI = dry matter intake; CP = crude protein; NDF = neutral detergent fiber; ADF = acid detergent fiber; TMS = total milk solid.