Non-living things protected??!?!?! what the hell are you talking 
about??? And why would cows eating grass be a problem? veggies,
vegans dont eat grass, surprisingly! As for an upset in the food
chain this is unsubstantiated bullshit, the reason there are so
many of these farm animals is becuase they are bred for food,
nature controls its own populations unless humans interfere.
We are not a part of the natural food chain as we manufacture 
our food ( farming?) to be a part of the food chain we would
take from the naturally occuring numbers of animals or plants
so as to maintain equilibrium. For someone who speaks about 
logic and common sense you dont half talk a load of bollocks!!