Dairy cows are raped. The calfs are immediately taken away from their mother.
The male calfs are intentionally malnourished for a few months and then killed. To make the meat tast better.
The mothers are stood up in the same spot and constantly milked until they can no longer stand. About 6 years. Then they are killed. They normally live about 15 years but the abuse is too much for them.
Well it's not as black and white as that when you have "vegetarians" who eat eggs, dairy, fish, and even some eat birds. And while some vegans are cult like many just don't have another way to describe their diet without using a couple of sentences.
Either way there is no doubt that not using or eating animal products is the best thing you can do if you want to help planet right now instead of in 200 years. It's going to go that way anyways at some point. I predict it will get very close to everyone avoiding animal products in 50 years, with only the very rich continuing to use animal products. Factory farming is just not sustainable in the long run. It's not even sustainable now.