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.

God ordered Vegetarians