Look... For every animal you don't eat, I will eat 3.
Man is an omnivore and meant to be omnivorous. Crack a book if you don't think that one to be true. Mankind was not meant to survive on a vegan diet alone. Babies sure as heck can't, yet the messed up in the head vegan types get charged regularly for child abuse. Why? The believe the wrong things when it comes to their babies diets. Not condemning all vegans here so don't misread those last comments! I know a few vegans myself. 2 are messed up in the head. Hence my "For every animal you don't eat, I will eat 3" comment. The others do so for very good and sensible reasons (all health related by the way). I quite agree with them too.

Man is also smart and has come up with different ideas and comes up with a new menu regularly. cow --> milk--> strawberry ice cream for example

Man is also gluttonous. Too much is just that.. too much. And too much anything is usually bad for you diet-wise.