When a cow is slaughtered, about half of its weight is not eaten by humans; the intestines and their contents, the head , hooves, and horns, as well as bones and blood. These are dumped into giant grinders at rendering plants, as are the entire bodies of cows and other farm animals known to be diseased. Rendering is a 2.4 billion a year industry, processing forty billion pounds of dead animals a year. There is simply no such thing in America as an animal too ravaged by disease, too cancerous, or too putrid to be welcomed by the all embracing arms of the renderer. Another staple of the renderer's diet, in addition to farm animals, is euthanized pets - six or seven million dogs, and cats that are killed in animal shelters , animal control agencies and road kill every year. When this gruesome mix is ground and steam cooked, the lighter, fatty material floating to the top gets refined for use in such products as cosmetics, lubricants, soaps, candles, and waxes. The heavier protein maerial is dried and pulverized into a brown powder- about a quarter of which is fecal material....
Animal excrement itself is also used to enrich these feed concentrates. Arkansas as example where the average cattle farmer feeds over fifty tons of chicken litter droppings to cattle every year. "One Arkansas cattle farmer was quoted in U.S. News and World Report as having recently purchased 745 tons of litter collected from the floors of local chicken-raising operations. After mixing it with small amounts of soy bran, he then feeds it to his eight hundred head of cattle, making them, in his words, "fat as butterballs".
Now if you are wondering whether this practice, other than sounding completely nauseating and revolting, can possibly be harmful to your health as a meat eater, the answer appears to be yes. Have you heard about mad cow disease which is now afflicting Great Britain? Some investigators believe that it originated with the feeding of ground-up, disease infected sheep to cows. The sheep disease is called scrapie, because intense itching makes sheep scrape off virtually all of their wool. Scrapie apparently manifests itself in cows as bovine spongiform encephalopathy (BSE) commonly reffered to as Mad Cow Disease.
The disturbing question is whether people who eat meat from such infected cows can suffer any health problems? While the British government has been busy assuring its citizens that Mad Cow disease is nontransmuterable to human beings, not everyone is convinced. Several researchers theorize that it is now appearing in humans as a slowly progressing brain disorder called Creutzfeldt-Jakob Disease (CID). At present, there is no treatment for CID and no test for its presence other than a biopsy of brain material at an autopsy.
According to Lyman's book the American rendering industry in 1989 voluntarily banned the use of sheep heads at rendering plants. An FDA survey three years later found that 15 of 19 rendering plants inspected were not observing the ban, and six of them were using the rendering sheep protein in cattle feed. "Unenforced safety regulations can do little more than lull us into a false sense of security," Lyman states.