Endocrine and morphological events in peripubertal heifers are similar to the resumption of cyclicity post partum in mature cows.
Puberty is attained with the first behavioural oestrus that is accompanied by ovulation and development of a corpus luteum with a typical lifespan.
Factors that can influence the pubertal rise in release of LH pulses are:
There are slight differences in the age at which heifers reach puberty and start cycling. Body weight is one of the factors which strongly influence the onset of puberty in cattle.
| Breed | Age at puberty (months) | Weight at puberty (kg) |
|---|---|---|
| Holstein Frisian – US type | 12-13 | 265-289 |
| HF – Australian type | 8-12 | 200-230 |
| Jersey | 8-10 | 160-180 |
| Brown Swiss | 10-11 | 280-300 |
| Charolais | 12-13 | 320-355 |
| Angus | 13-14 | 300-310 |
| Hereford | 14-15 | 300-310 |
| Simmental | 11-12 | 320-330 |
| Zebu type | 17-27 | 330-350 |
