I was checking out on “Greaves Meal” listed as an Ingredient in a Pet Food world-widely distributed and I learnt about “Rendering” which is a provocative thought especially when one looks from the perspective of what is in Commercial Pet Foods.
Materials which are processed are majorly from slaughterhouses and can include fatty tissue, bones, and offal. Other sources include Grease from restaurants, Trimmings from butchers, Expired Meat from grocery stores, and Carcasses of Euthanized and/or Dead Animals from Animal Shelters, Zoos and Veterinarians and include entire carcasses of animals condemned at slaughterhouses, and those which have died on farms, in transit, and so forth.
The Rendering Process simultaneously dries the Materials and separates the Fat from the bone yielding a Fat Commodity (Yellow Grease, Choice White Grease, Bleachable Fancy Tallow, etc.) and Protein producing a Protein Meal (Meat & Bone MEAL, Poultry by-product Meal, etc.).
Rendering, one of the oldest RECYCLING industry, was in fact, developed to make useful what would otherwise had been waste materials, at the same time resolving prominent animal-material-waste disposal issues, especially in industrial-scale-slaughtering areas, costs of which would had been sky-high, detrimental to the economy and environment, and relinquished all earnings; and from that, a profitable massive Meat Food Industry was birthed, making food more economical for consumers.
(It was also due Upton Sinclair’s expose in 1906 in relation to the Chicago Meat Industry in US which led to public outrage, thereon the introduction of the Pure Food and Drug Act of 1907 and later the passageway to FDA’s formation.)
Edible rendering processes, done mostly by Meat packing or processing companies, are basically Meat Processing Operations to produce Lard or edible Tallow for Food Industry use, whereby the finely-chopped edible Fat-materials (generally fat trimmings from meat cuts) are heated with or without added steam, then put through stages of Centrifugal Separation (2 or more):
1. Fat & Liquid Mixture separated from the Solids, then followed by
2. Fat being separated from the Liquid
The separated Solids are used in Food Products, Pet Foods, etc., dependent upon the original materials. The separated Fat may be used in Food Products, or if in surplus, for Soap making.
GREAVE, which is the remaining unmeltable residue, is one edible product.
There is yet another alternative rendering process which cooks Slaughterhouse Offal to produce a Thick, Lumpy “STEW” which is then sold to the Pet Food Industry to be used principally as Tinned Cat and Dog Foods. (Such rendering plants are notable for the offensive odour they produce and are often located well away from human habitation!)
INEDIBLE Fat Waste, done mostly by independent rendering companies, was originally used to make soaps for both domestic and industrial washing until after WWII, when synthetic detergents were brought out, subsequently diverted to make ANIMAL FEEDS and eventually largely constituted for the ANIMAL FEED production.
Therefore, the same LOW-COST fat-waste raw material which is used to make, soap, grease, candle, biodiesel, and feed-stock for the chemical industry, is also used to make ANIMAL FEED; and previously been fed to cattle but ceased for fear of BSE (mad-cow disease), is still being fed to non-ruminant Animals and Domestic Pets (eg. Pedigree) in the form of Meat & Bone Meal (MBM).
MBM are mostly made from dry rendering (dry, ground state), however, some through wet rendering where the materials are heated with added steam, thereon pressed to remove a Water-Fat mixture which is then separated into Fat, Water and fine Solids through stages of Centrifuging and/or Evaporation, whereof then the solids from the press are Dried and subsequently Ground into MBM.
In the earlier days, Solids from “Tanking” (previous wet-rendering process), were used to make fertilizers, and the remaining “Tank Water” (after the free fat is “Tanked” (“run off”)) either ran into a sewer or evaporated to make Glue or Protein Concentrate which is then adding into fertilizers.
What are your thoughts??
And, if BSE is fatal to human, how safe is it to other animals being fed with the similar ANIMAL FEED?
Abstracted from Wikipedia Sources: