Table 2.
Effect of BCS change (mean ± SEM) on pregnancies per AI (P/AI) for cows on farm 1 and 2 classified as losing, maintaining, or gaining BCS from parturition to 3 wk postpartum
| Item | BCS change1 | P-value | ||||
|---|---|---|---|---|---|---|
|
|
|
|||||
| Lost | Maintained | Gained | BCS change | Parity | BCS change × parity | |
| All cows | ||||||
| % of cows (n/total no.) | 41.8 (789/1,887) | 35.8 (675/1,887) | 22.4 (423/1,887) | |||
| P/AI at 40 d [% (no./total no.)] | 25.1 (198/789)c | 38.2 (258/675)b | 83.5 (353/423)a | <0.001 | <0.001 | 0.37 |
| P/AI at 70 d [% (no./total no.)] | 22.8 (180/789)c | 36.0 (243/675)b | 78.3 (331/423)a | <0.001 | <0.001 | 0.19 |
| Pregnancy loss [% (no./total no.)] | 9.1 (18/198) | 5.8 (15/258) | 6.2 (22/353) | 0.34 | 0.41 | 0.57 |
| BCS at parturition | 2.93 ± 0.01a | 2.89 ± 0.02b | 2.85 ± 0.02b | 0.005 | <0.001 | 0.05 |
| BCS at 21 DIM | 2.64 ± 0.01c | 2.89 ± 0.02b | 3.10 ± 0.02a | <0.001 | <0.001 | 0.06 |
| ECM2 (kg/d) | 30.9 ± 0.4 | 31.5 ± 0.4 | 28.7 ± 0.4 | 0.30 | 0.002 | 0.74 |
| Farm 1 | ||||||
| % of cows (n/total no.) | 42.5 (347/817) | 49.5 (405/817) | 8.0 (65/817) | |||
| P/AI at 40 d [% (no./total no.)] | 36.0 (125/347) | 37.5 (152/405) | 43.1 (28/65) | 0.60 | <0.001 | 0.95 |
| P/AI at 70 d [% (no./total no.)] | 32.3 (112/347) | 35.8 (145/405) | 41.5 (27/65) | 0.35 | <0.001 | 0.99 |
| Pregnancy loss [% (no./total no.)] | 10.4 (13/125) | 4.6 (7/152) | 3.6 (1/28) | 0.16 | 0.97 | 0.57 |
| BCS at parturition | 2.91 ± 0.02 | 2.89 ± 0.02 | 2.82 ± 0.02 | 0.26 | 0.001 | 0.33 |
| BCS at 21 DIM | 2.60 ± 0.02c | 2.89 ± 0.02b | 3.07 ± 0.02a | <0.001 | 0.002 | 0.38 |
| ECM2 (kg/d) | 34.2 ± 0.6 | 34.1 ± 0.5 | 33.9 ± 1.5 | 0.91 | 0.04 | 0.51 |
| Farm 2 | ||||||
| % of cows (n/total no.) | 41.3 (442/1,070) | 25.2 (270/1,070) | 33.5 (358/1,070) | |||
| P/AI at 40 d [% (no./total no.)] | 16.5 (73/442)c | 39.3 (106/270)b | 90.8 (325/358)a | <0.001 | 0.04 | 0.42 |
| P/AI at 70 d [% (no./total no.)] | 15.4 (68/442)c | 36.3 (98/270)b | 84.9 (304/358)a | <0.001 | 0.02 | 0.24 |
| Pregnancy loss [% (no./total no.)] | 6.8 (5/73) | 7.5 (8/106) | 6.5 (21/325) | 0.89 | 0.97 | 0.27 |
| BCS at parturition | 2.95 ± 0.02a | 2.88 ± 0.02ab | 2.85 ± 0.02b | 0.007 | <0.001 | 0.48 |
| BCS at 21 DIM | 2.67 ± 0.02c | 2.88 ± 0.02b | 3.10 ± 0.02a | <0.001 | <0.001 | 0.52 |
| ECM2 (kg/d) | 28.4 ± 0.4 | 27.7 ± 0.6 | 27.9 ± 0.5 | 0.37 | <0.001 | 0.52 |
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.
2
Average ECM from calving to 21 DIM.