Pet Food Terminology
Meal: A ground or pulverized composite of animal feed-grade ingredients.
Rendering: Rendering is "to process as for industrial use: to render carcasses and to extract oil from fat, blubber, etc., by melting." To reduce, convert, or melt down (fat) by heating.
Extruding: The term used to describe a heat and pressure system used to "puff" dry foods into nuggets or kibbles.
Gluten: The dried residue from corn or wheat after removal of the starch, germ and bran. Used as a source of protein.
Meat & Poultry By-products: By definition a by-product is "An ingredient produced in the course of making a primary food ingredient; a secondary or incidental product." These ingredients are pressure cooked until they are an edible gel. Typically these meats are derived from the "4 Ds": dead, dying, diseased or decayed animals. Byproducts are composed of meats unfit for human consumption, this includes horns, beaks, feathers, feces, urine, pus, tumors, etc. These may also include animals which have excess levels of drugs (antibiotics, pesticides, etc).
Beet pulp: A rather controversial product, many think that it is an excellent additive and source of fiber and that all sugar has been completely extracted before being added as a pet food ingredients. If this is the only "problem" ingredient in a kibble, other factors will have to help you decide.
Brewer's dried yeast: Left over from the beer brewing industry.
Brewer's rice: A byproduct of the beer brewing industry. It may also contain pulverized dried hops. This is a low quality rice product that is missing many of the nutrients found in ground rice & brown rice. No nutritional value.
Copper sulfate: This substance is highly corrosive to steel, iron and galvanized pipes.
Corn gluten meal: Dried residue from corn after the removal of starch, germ and bran. No nutritional value.
Dried whole eggs: Rejects from hatcheries which are unfit for human consumption.
Ferrous sulfate: Made up of elemental iron which depletes vitamin A.
Ground yellow corn: Ground or chopped yellow corn. No nutritional value. This food is actually thought to be a common cause of food allergies in dogs and cats.
Iron oxide: Rust, like that found on cars.
Rice bran: Is "an inexpensive source of fiber that is considered a filler ingredient". No nutritional value.
Rice flour: This is a highly pre-processed ingredient. All of the naturally occurring vitamins have been leeched out by the processing. Ground Rice with its natural nutrients intact would be preferable.
Sodium Nitrate: The FDA has stated that this chemical is hazardous to human health. It adds a rosy color to pet food, however.
Vegetable Fiber: May contain ground up corn husks, peanut shells and sawdust.