The farmer is usually responsible for getting the beef to the slaughterhouse.
Specific types of meat, such as beef meal or chicken by-products, actually come from the type of animal listed but can be slaughterhouse rejects known as the 4d's - dead, dying, diseased, and disabled animals.
Bacteria - Bacteria makes its way into the pet food supply because animals that are sick or dying before they reach the slaughterhouse can be used in the food.
The law requires that slaughterhouse rejects be denatured before being sent to rendering plants to insure that they will not be sold for human consumption.
Gelatin, a by product of the slaughterhouse industry, is often used to make gel capsules.