The dairy and beef industry are not sustainable, especially with the way water is these days.
Plants based sources of calcium are better for your bones than milk is. Can we all agree on that?
My gf drinks local raw goats milk and loves it.
I've made many posts on the environmental damage caused by the raising of 1.3 billion head of cattle on planet earth. Nothing else comes close to the scope of said damage. All the grain wasted to feed them, all the pesticides and fertilizers used to grow said grain, which end up in our oceans and all the deforestation for the purpose of growing more soy to feed cattle, not to mention the immense water use (50% of water in western U.S. used for cattle) all make dairy farming and cattle ranching our #1 environmental problem. I won't get preachy about it in this thread, but if you want to learn more, Google "environmental effects of cattle ranching". It's at once shocking and depressing.
By the way, supposedly the healthiest type of milk is camel's milk. It is very expensive, and not too much fun to try and milk a camel.