Tecnically, the Sun, because the Sun transfers it's energy to plants through sunlight and plants transfer energy to cows through digestion.
Cows actually do not make food. Humans are responsible for that sector of the economy.
Cows can get food on their own when they are out on pasture. The act to which they are able to do so is called "grazing."
The same type of food that all other cows eat.
the probing of cows
Cows make milk from eating grass.
Cows and dogs have different feedstuff requirements, thus there is no one food that contains vitamins (or any other nutrient) for both cows and dogs.
No.
the cows digestion takes 8 hours to digest the food or cud
Hay.
No, they are herbivores.
Food Production
Digesting food.