Table 3.
Effect of BCS change (mean ± SEM) from parturition to 3 wk postpartum on pregnancies per AI (P/AI) for primiparous and multiparous cows
| Item | BCS change1 | P-value | ||
|---|---|---|---|---|
|
| ||||
| Lost | Maintained | Gained | ||
| % Primiparous (no./total no.) | 47.3 (373/789)b | 52.7 (356/675)a | 55.1 (233/423)a | 0.02 |
| Primiparous | ||||
| P/AI at 40 d [% (no./total no.)] | 30.8 (115/373)c | 46.9 (167/356)b | 85.8 (200/233)a | <0.001 |
| P/AI at 70 d [% (no./total no.)] | 28.7 (107/373)c | 44.4 (158/356)b | 80.3 (187/233)a | <0.001 |
| Pregnancy loss [% (no./total no.)] | 7.0 (8/115) | 5.4 (9/167) | 6.5 (13/200) | 0.85 |
| BCS at parturition | 2.83 ± 0.02a | 2.84 ± 0.02a | 2.76 ± 0.02b | 0.01 |
| BCS at 21 DIM | 2.54 ± 0.02c | 2.84 ± 0.02b | 3.01 ± 0.02a | <0.001 |
| ECM from calving to 21 DIM (kg/d) | 31.3 ± 0.5 | 32.1 ± 0.5 | 28.1 ± 0.5 | 0.69 |
| ECM near TAI (kg/d) | 31.2 ± 0.3 | 31.4 ± 0.3 | 32.0 ± 0.4 | 0.47 |
| Multiparous | ||||
| P/AI at 40 d [% (no./total no.)] | 20.0 (83/416)c | 28.5 (91/319)b | 80.5 (153/190)a | <0.001 |
| P/AI at 70 d [% (no./total no.)] | 17.5 (73/416)c | 26.6 (85/319)b | 75.8 (144/190)a | <0.001 |
| Pregnancy loss [% (no./total no.)] | 12.0 (10/83) | 6.5 (6/91) | 5.9 (9/153) | 0.23 |
| BCS at parturition | 3.03 ± 0.02a | 2.94 ± 0.02b | 2.95 ± 0.02b | 0.02 |
| BCS at 21 DIM | 2.73 ± 0.02c | 2.94 ± 0.02b | 3.20 ± 0.02a | <0.001 |
| ECM from calving to 21 DIM (kg/d) | 30.6 ± 0.5 | 30.8 ± 0.6 | 29.5 ± 0.8 | 0.49 |
| ECM near TAI (kg/d) | 41.1 ± 0.4 | 41.6 ± 0.4 | 41.7 ± 0.5 | 0.40 |
a–c
Values within a row with different superscript letters differ at P < 0.05.
1
Cows had their BCS evaluated at calving and at 21 DIM using a 5-point scale with 0.25 increments.