Not all calves, but most. They need to keep the cows lactating, so they need to keep having calves. There is some work on selectively breeding to produce female

Not all calves, but most. They need to keep the cows lactating, so they need to keep having calves. There is some work on selectively breeding to produce females, but even then there are more females born than are useable for milk production. They are separated from their mothers as early as 1 day after birth and are normally sold at 2 weeks of age. Veal is meat from calves that are only weeks old, anywhere from a few weeks to about 8 months old. There's varied opinions on if this is acceptable animal welfare. But basically, calves are a byproduct of milk production.