What the cows eat. Cows, mainly, eat grass, hay and silage (fermented grass, alfalfa or grain). Cows also eat a lot of waste, which usually remain after people. Wastes include soybean meal, beet pulp, cotton seeds, citrus pulp and bakery waste (making bread).
In summer cows eat mostly fresh grass. In the winter, they switch to hay, silage and root crops harvested by the farmer.
Grass is the cheapest and most useful food for cows, so in summer they are simply driven out to the pasture and left to graze for their own pleasure. Usually grass grows larger than cows can eat, so it is mowed and dried to feed animals in winter.
The grass can be harvested in the form of silage or hay. Silage is a short, juicy grass that is mowed, left for 24 hours, and then shredded and folded into large plastic bags. After three months, silage is ready for consumption. Hay is made from a long grass, mowing it and leaving to dry on the field before being transported to the hay store. Cooking hay is more difficult than silage, because here you are totally dependent on the weather.
In winter, cows are kept indoors so that they do not spoil their wet hooves with their wet pastures.