(M)eat production depends upon a system of protein-components-in and far-less-protein-out. As well as protein that is not absorbed but is excreted, livestock animals need a substantial bone-structure, hoof, horn and all the body parts that we don’t eat. This is where a good deal of the nutritional contents of grains and soy ends up when it is fed to livestock. Some of this can be recycled in various ways but much of it is straightforwardly lost. Feeds also have to sustain animal movement and that involves energy loss of a more straightforwardly unrecovarable sort.
We may then wonder why humans ever farmed animals at all but the answer to this is simple. Some nutrients are difficult to access or to process (such as the acorns that pigs love to eat). But more fundamentally, we lacked any other way to access the nutrients in certain kinds of grasses. Cattle can eat what we find indigestible. (..)
|Vaca e vitelos da raça Maronesa na serra; terreno inacessível para cultivo. Imagem de http://autoctones.ruralbit.com/|
The simple model of cattle eating grass and humans then eating cattle is an efficient solution to tap into the available natural resources. But once cattle are fed on grains and pulses instead of grass or difficult-to-access nutrients, that is on foods that humans can without any great difficulty eat (and enjoy and be creative with), meat production becomes grossly inefficient. (…) The only merit of meat produced in this way is that it continues to supply us with complete proteins and relieves us of the daily burden of having a more varied diet. Contemporary meat-eating may not be a dietary formula for gluttony but it is a formula for a certain kind of dietary laziness that has little in common with the meat-eating of our ancestors.