Ethicist: On average, animals raised on grain must be fed sixteen pounds of grain to produce one pound of meat  A pound of meat is more nutritious for humans than a pound of grain, but sixteen pounds of grain could feed many more people than could a pound of meat
With grain yields leveling off, large areas of farmland going out of production each year, and the population rapidly expanding, we must accept the fact that consumption of meat will soon be morally unacceptable
Often, cattle or sheep can be raised to maturity on grass from pastureland that is unsuitable for any other kind of farming.