It really depends on where you live and what major threats with predators and cattle theft you have in your area. If you are that concerned about your cattle getting killed or injured by predators or having them stolen, then there's nothing wrong with putting them in at night. However, if you know your animals are big enough to look after themselves, you don't have a significant threat of predator damage and/or theft, then don't bother.
cows
Hawks, roosters, snakes, cows, and some forms of elephants
Yes they do.
Not referee cows.
In one of the pens, put two cows.
milk duds
You should start calving season by March 16.
The night before St.Patricks day.
Yes, most do.
Maybe you should tell us where you are located first before we can answer this question.
A couple months after the cows have calved.
you should of asked they're mother last night!