Table 7.
Pregnancy and calving percentages of heifers that achieved puberty before the start of the breeding season (pubertal) and heifers that were prepubertal at the start of the breeding season but achieved puberty before the end of the breeding season
| Puberty status at the start of the breeding season1 | P-value | |||||
|---|---|---|---|---|---|---|
| Item1 | Non-pubertal | Pubertal | P-value2 | SEM | Supp. amount × puberty status | Supp. frequency × puberty status |
| Pregnant heifers, % of total | ||||||
| Supplement at 1.25% of BW | 10.3 | 76.0 | <0.0001 | 12.4 | 0.07 | 0.52 |
| Supplement at 1.75% of BW | 58.8 | 87.7 | 0.07 | 12.4 | ||
| P-value3 | 0.015 | 0.18 | ||||
| Calving, % of heifers that calved | ||||||
| Supplement at 1.25% of BW | 6.17 | 65.8 | 0.001 | 15.8 | 0.10 | 0.87 |
| Supplement at 1.75% of BW | 56.4 | 73.5 | 0.22 | 15.8 | ||
| P-value3 | 0.05 | 0.53 |
1Heifers grazed bahiagrass pastures and were randomly assigned, in a 2 × 2 factorial design, to receive concentrate DM supplementation at 1.25% or 1.75% of BW offered either daily or 3× weekly (Monday, Wednesday, and Friday) from days 0 to 168 (2 yr; 64 heifers/yr; 4 pastures/treatment combination/yr). At the start of the breeding season, 12 and 7 heifers were considered prepubertal in years 1 and 2, whereas 52 and 57 heifers attained puberty before the start of the breeding season in years 1 and 2, respectively.
2 P-value for the comparison of puberty status within supplementation amount.
3 P-value for the comparison of supplementation amount within puberty status.