Ideally, during the right season of the year, cows should calve out on pasture. There should be shade and no bodies of low standing water in which the calf can drown. A catch pen is essential if assistance needs to be provided. The latter should be equipped with a source of clean water, cover against the weather and a light source for night time deliveries. The pasture should be large enough to keep it from becoming a contaminated mud hole with repeated use.
Drost M (2009)