Table 1.
Fertility performance of each bull expressed as conception rate after fixed-time artificial insemination (FTAI). Pronuclei visualization, cleavage rates, and blastocyst formation rates (means ± SD) observed at 12, 72, and 168 hours after in vitro fertilization, respectively.
| Bull | Inseminated cows | Conception rate after FTAI (%)* | Total oocytes | Analyzed zygotes | Pronuclei (%) | Cleavage** (%) | Blastocyst** (%) |
|---|---|---|---|---|---|---|---|
| V | 149 | 54.4 | 344 | 40 | 52.5 ± 1.7 | 77.9 ± 1.0b | 27.9 ± 0.5 |
| T | 109 | 54.1 | 341 | 40 | 40.0 ± 1.6 | 57.4 ± 0.4a | 22.8 ± 0.4 |
| G | 234 | 63.3 | 312 | 30 | 40.0 ± 1.8 | 78.1 ± 1.8b | 30.5 ± 0.5 |
a,bValues with different superscripts in the same column are significantly different (P < .05).
*Percentage calculated based on the number of pregnant cows in relation to the total number of inseminated cows.
**Percentage calculated based on the total number of oocytes minus the zygotes removed for pronuclei evaluation.