Table 1. Metabolizable and net energy requirements for pregnant Holstein × Gyr cows.
| Days of pregnancy | Net energy for pregnancy (kcal/day) | Metabolizable energy for pregnancy (kcal/day) | ||
|---|---|---|---|---|
| This study1 | Ferrell et al. (1976)2 | This study1 | Ferrell et al. (1976)2 | |
| 100 | 87 | 36 | 620 | 257 |
| 130 | 133 | 74 | 947 | 527 |
| 160 | 204 | 143 | 1445 | 1021 |
| 190 | 311 | 263 | 2206 | 1879 |
| 220 | 475 | 457 | 3368 | 3264 |
| 250 | 725 | 752 | 5141 | 5371 |
| 280 | 1107 | 1167 | 7848 | 8336 |
1 Energy requirements for pregnancy calculated according to the estimated equation in this study. Efficiency of utilization of metabolizable energy for pregnancy = 14.1%. Net energy for pregnancy denotes energy retained in gravid uterus and mammary gland.
2 Energy requirements for pregnancy adapted from Ferrell et al. [1]. Efficiency of utilization of metabolizable energy for pregnancy = 14%. Net energy for pregnancy denotes energy retained in gravid uterus and mammary gland.