Once every 11 to 12 months, accounting for the period of rest a cow gets after being bred (which will last from 2 to 3 months), and the gestation period for that cow after she has conceived.
The same as any other cow that lives elsewhere in the world: one year in between calvings.
A cow that is very close to calving or which calving is imminent.
Calving.
A breaching cow could mean a cow that is calving out a backwards calf.
Yes, always.
A cow that is close to calving, and is far along in her gestation period.
Parturition or calving, just like with any other cow.
the cow will get restless and will isolate itself from other cows.
A calving pen, or out on the pasture.
For one cow, it's usually 11 to 12 months in between each calving. For a cow-calf operation with defined breeding and calving seasons, it's always 12 months in between the start of one season to the start of the next.
Absolutely nothing. A pig doesn't care nor cannot help a calving cow.
It means that a cow is giving birth to a newborn baby calf.