"Chicken by-product meal" "Meat and bone meal" and other similarly worded ingredients are commonly found on pet food lables. These meals are created at rendering plants.
Some rendering information:
This is about water usage in rendering plants, however if you read it it tells you what is actually being rendered in those plants
From this article "At issue is an organ slurry - a mixture of ground cattle offal, including liver and lungs that is commonly used in pet food."
This one is kind of gross "Mims Meat has strict protocols for waste management and disposal. According to Renfro, processing waste is placed in barrels marked “inedible,” and a green denaturing agent is poured on top so it cannot be used for anything else. The barrels are covered to minimize odors and prevent unwanted access; they are also stored in a cooler, where the controlled temperature serves as a deterrent to insects. A rendering company picks up the carefully contained waste once a week."
from the EPA website http://www.epa.gov/ttn/chief/ap42/ch09/final/c9s05-3.pdf
"Independent plants obtain animal by-product materials, including grease, blood, feathers, offal, and entire animal carcasses, from the following sources: butcher shops, supermarkets, restaurants, fast-food chains, poultry processors, slaughterhouses, farms, ranches, feedlots, and animal shelters."
What is 'chicken by-product meal' made of?? The answer from the same document:
Poultry Feathers And Hog Hair Processing —
The raw material is introduced into a batch cooker, and is processed for 30 to 45 minutes at temperatures ranging from 138° to 149°C (280° to 300°F) and pressures ranging from (40 to 50 psig). This process converts keratin, the principal component of feathers and hog hair, into amino acids. The moist meal product, containing the amino acids, is passed either through a hot air, ring-type dryer or over steam-heated tubes to remove the moisture from the meal. If the hot air dryer is used, the dried product is separated from the exhaust by cyclone collectors. In the steam-heated tube system, fresh air is passed countercurrent to the flow of the meal to remove the moisture. The dried meal is transferred to storage. The exhaust gases are passed through controls prior to discharge to the atmosphere.
"Materials used in rendering include slaughterhouse offal and inedible materials, deadstock, and/or restaurant grease and fat. Currently, modifications in rendering are under way so that these materials will be separated by species, or be absent of specified risk materials (SRMs). Those materials defined as SRMs include the skull, brain and the nerves attached to them, the spinal cord and nerves attached to it, eyes and tonsils in cattle aged 30 months and older."
And last but not least, here is a list of links about rendering. Some of the referenced articles are a bit 'green' for my taste, but some are very interesteing, especially the one called "How Dead Pets, Bad Brains, and Free Speech Landed Me in Amarillo" which is partially about the U.S. District Court case of Texas Beef Group vs. Oprah Winfrey.
Do I still feed kibble? Yup. Will I continue to feed it because I currently do not make the time to make my pets a home cooked diet? Yes. However, I know, and do not deny, exactly what is in the food I am feeding my dog.