An excellent question.

Did any one ask animals for permission to kill them.
What kind of after life do animals have after they are slaughtered?
Why animals have fears, feel pain and instinctively know how to survive?
Why do animals become what they are in the first place?
Why do hunters go crazy and die in the hunting ground?

If the answer is that animals are created for men's consumption, it is simply a brush off.
Would you like to sit on stove or in a frier with boiling oil.

Why some people behave like animal. Their conscious levels are lower than others.

Look around you and think deeper, you will find the answer.