| I | calve |
|---|---|
| you | calve |
| he/she/it | calves |
| we | calve |
| you | calve |
| they | calve |
| I | calved |
|---|---|
| you | calved |
| he/she/it | calved |
| we | calved |
| you | calved |
| they | calved |
| I | have | calved |
|---|---|---|
| you | have | calved |
| he/she/it | has | calved |
| we | have | calved |
| you | have | calved |
| they | have | calved |
| I | had | calved |
|---|---|---|
| you | had | calved |
| he/she/it | had | calved |
| we | had | calved |
| you | had | calved |
| they | had | calved |
单语范例（未经PONS编辑处理）
Lactation length is 350 days, calving interval is 465 days.
en.wikipedia.org Milk yield varies according to season of calving, lactations number, level of feeding, and length of lactation.
en.wikipedia.org The test station evaluates weight, growth, morphology, fertility, calving ability and milking ability in order to assess their maternal qualities.
en.wikipedia.org The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions.
en.wikipedia.org Following the breeding schedule, spring was calving and round up.
en.wikipedia.org