Table 6.
The DHI changes of Holstein cows at different lactation stages.
| Items | Peak Lactation Stage |
Middle Lactation Stage |
End Lactation Stage |
|---|---|---|---|
| somatic cell score | 2.3 ± 0.31 b | 3.1 ± 0.25 ab | 3.1 ± 0.19 a |
| milk yield (kg/d) | 33.2 ± 2.09 a | 38.9 ± 1.19 a | 32.1 ± 0.93 b |
| Protein (%) | 3.4 ± 0.05 a | 3.4 ± 0.03 a | 3.4 ± 0.03 a |
| Lactose (%) | 5.2 ± 0.04 a | 5.2 ± 0.03 a | 5.2 ± 0.02 a |
| fat (%) | 4.4 ± 0.15 a | 4.1 ± 0.11 a | 4.0 ± 0.08 a |
| dry matter (%) | 13.7 ± 0.14 a | 13.4 ± 0.12 a | 13.3 ± 0.08 a |
| urea nitrogen (mg/dL) | 12.1 ± 0.51 a | 12.5 ± 0.50 a | 11.8 ± 0.33 a |
All data are expressed by the mean ± standard error, (n = 21 during peak lactation, n = 54 during middle lactation and end lactation: n = 98). Different letters in the same rows are significant (p < 0.05), and the same letters are not significant (p > 0.05).