👉 Calving is a physiological process in cows, where their mammary glands release milk from the cow's milk-producing glands. It occurs when the mammary glands start producing more milk than they can produce and the cow needs to stop pumping milk. The process of calving involves several stages: the first stage, also known as calving day, is when the mammary glands begin to produce more milk; the second stage is the "calving" stage, during which the mammary glands release their