Why do cows produce so much milk?

The milk production process is cruel. Matter is immortal, energy is conserved, and there will be no milk in the sky. Now we know that all the milk we drink comes from an animal called a cow. So, why do cows produce milk? Many people don't know this question, and I used to be very vague. Now I can finally confirm that the cow produces milk because it gave birth to calves. No female mammal drips milk from her breasts every day for no reason. So why do cows give birth to calves? Because it's pregnant. Why do cows get pregnant? Many people take it for granted that they know this problem-in fact, it is because it has been artificially fertilized! Furthermore, why do cows keep producing milk? Because it keeps giving birth to calves. Why do cows keep giving birth to calves? Because it has been pregnant. How can cows be pregnant all the time? Because it is constantly artificially fertilized. Like meat food, the milk we drink now comes from factory farming, not traditional animal husbandry. Cows on dairy assembly lines may never see a bull, but they keep giving birth to calves and being milked. Even in advanced dairy factories, cows can't see their children at all, and calves can't see their mothers, so they are separated from their mothers at birth. Some heifers were fed as cows, repeating her mother's fate; Some calves are sold as beef cattle, and they are lucky; There are also some calves that go directly into biochemical factories and become various serums, protein and enzymes! Excerpted from Reader 16, 2008. How much does it cost to drink milk?