Holy Bible - Genesis
1:29 - I have provided all kinds of grain and all kinds of fruit for you to eat;
1;30 - but for all the wild animals and for all the birds I have provided grass and leafy plants for food -and it was done.
While creating nature God clearly provided grains, fruits, grass and leafy plants as food for humans and animals. Hence He ordered them to be vegetarians.
I believe that too! I'm vegetarian.