> what happens to dairy [calves] if there is no veal trade?

Veal is a by-product of the dairy industry. You can't make milk and cheese without making veal. To produce milk, cows must become pregnant. Half of the calves will be male, so cannot be used in the dairy industry. These calves are not beef cattle so cannot be raised for the beef industry either.

In countries where there is no consumer demand for veal, these male calves are killed and thrown in the bin. A waste of life, but one which happily most people choose to ignore.

If you choose to eat beef but not veal, you're causing the deaths of more cows, and the calves are killed whether you want to eat them or not. Killing an animal and eating it is fine with me, but it's indefensible to kill it and throw it away because it's cute.