Whereas obtaining Milk and other animal bi-products often requires violence to be perpetrated on animals within the standard dairy and egg industry, which we should oppose, it does NOT require one to do so. This is evident in backyard-eggs, and Ahimsa farms where farmers treat their cows as family members, abstaining from industry standards like the rape of cows, separation of calves from their mothers and the shipping of these cows to slaughter. 

Whereas I promote Veganism, there is nothing inherently morally wrong with(Ovo/Lacto) vegetarianism. 
Many Vegans make generalisations by assuming animal bi-products can not be obtained from an animal without violence and animals cannot consent which is definitively false. 
Vegans that make this argument are making an appeal to potentiality fallacy by applying standard industry practices and assuming that's always the case which it is not. 

See Ahimsa farms https://youtu.be/iJrv4mw_QgI