Table 2 Lactation curve parameters of lactations with calving season July to September, average of 8.69 MJ to 12.83 MJ of daily energy from concentrates and no records of veterinary treatments throughout lactation, of Norwegian dairy cattle during the period 2005 to 2007.
Early conception (from 43 to 93 DIM) | Late conception (after 93 DIM) | |||
|---|---|---|---|---|
Estimate | SE 4 | Estimate | SE 4 | |
First parity (12,758 lactations and 121,552 test days) | ||||
Intercept (kg) | 12.83*** | 0.11 | 13.94*** | 0.11 |
Ascending slope (kg/days) | 3.42*** | 0.03 | 2.96*** | 0.03 |
Descending slope (kg/days) | -0.0643*** | 0.0004 | -0.0519*** | 0.0004 |
Peak day1 | 53.19 (51.57-54.85)3** | 57.13 (55.05-59.27) 3** | ||
Peak yield2 (kg) | 23.01 (22.51-23.51) 3 | 22.96 (22.43-23.50) 3 | ||
Second parity (5,651 lactations and 53,779 test days) | ||||
Intercept (kg) | 19.13*** | 0.14 | 20.23*** | 0.15 |
Ascending slope (kg/days) | 3.17*** | 0.04 | 2.71*** | 0.04 |
Descending slope (kg/days) | -0.0814*** | 0.0005 | -0.0689*** | 0.0005 |
Peak day1 | 38.95 (37.45-40.48) 3 | 39.33 (37.51-41.21) 3 | ||
Peak yield2 (kg) | 27.57 (26.95-28.19) 3 | 27.48 (26.83-28.13) 3 | ||
Third or later parity (4,640 lactations and 44,207 test days) | ||||
Intercept (kg) | 19.81*** | 0.15 | 20.91*** | 0.16 |
Ascending slope (kg/days) | 3.89*** | 0.05 | 3.43*** | 0.05 |
Descending slope (kg/days) | -0.0984*** | 0.0006 | -0.0859*** | 0.0006 |
Peak day1 | 39.53 (38.18-40.90) 3 | 39.92 (38.35-41.54) 3 | ||
Peak yield2 (kg) | 30.22 (29.55-30.89) 3 | 30.13 (29.44-30.82) 3 | ||