@johnnynull I'm afraid cows humans tend to eat don't grow on natural grass, rainfall and sunshine. So whatever resources required for today's live stock is undoubtedly _more_ than the original requirements of resources for feeding animals which are not bred explicitly for slaughtering (mainly since there'd be fewer cows etc. bred then).

Of course one may wish to argue that the laws of thermodynamics (when output > input) are outdated and that today's efficient industrialization laughs in the face of puny scientific reasoning!

(PS. cows stuffed with antibiotics reasonably produce pretty useless poop for fertilizing etc, so there is little possible reuse of waste products in the process of growing a cow up to the point of slaughtering).