As I understand, in the UK, nearly all male calves born to dairy cattle are slaughtered and disposed of as waste currently. Very few are raised for veal (iirc traditional white veal no longer produced here due to cruelty?).
You have to look at these things holistically - once agriculture was developed, but before industrialization, there was no real need to eat animals. Milk was an excellent nutritional resource and bullocks could be raised as work animals. However the circumstances are continuously changing - we have developed specialized breeds, use engines for work and transport and so on... so even obtaining milk means animals being bred and, wastefully, killed .
Even as a vegan it is difficult to claim that you don't contribute to animal deaths, just in planting, growing and reaping vegetable foods millions of animals may be killed. Just as an individual operating in the overall economy, where most other people eat meat, you support animal deaths; it's more a question of how closely or directly you want to be involved in them, and which choices you can make that will have the biggest effect in making the meat industry less economic.
