It all depends on your point of view. That is because everyone must produce ONE thing and that’s it. Everything else is BI oh By..by product by catch bye bye. So we consume the world tossing half of it to the side. Why?

http://en.wikipedia.org/wiki/By-product

A by-product is a secondary or incidental product deriving from a manufacturing process, a chemical reaction or a biochemical pathway, and is not the primary product or service being produced. A by-product can be useful and marketable, or it can have negative ecological impact. :}

Some of which include:

Animal sources

• dried blood and blood meal – from slaughterhouse operations
• chicken by-product meal – clean parts of the carcass of slaughtered chicken, such as necks, feet, undeveloped eggs, and intestines.
• chrome shavings – from a stage of leather manufacture
• collagen and gelatin – from the boiled skin and other parts of slaughtered livestock
• feathers – from poultry processing
• lanolin – from the cleaning of wool
• manure – from animal husbandry
• meat and bone meal – from the rendering of animal bones and offal
• poultry byproduct and poultry meal – made from unmarketable poultry bones and offal
• poultry litter – swept from the floors of chicken coops
• whey – from cheese manufacturing
• fetal pigs

 Vegetation

• acidulated soap stock – from the refining of vegetable oil
• bran and germ – from the milling of whole grains into refined grains
• brewer’s yeast – from ethanol fermentation
• corn stover – residual plant matter after harvesting of cereals
• distillers grains – from ethanol fermentation
• glycerol – from the production of biodiesel
• grape seed oil – recovered from leftovers of the winemaking process
• molasses – from sugar refining
• orange oil and other citrus oils – recovered from the peels of processed fruit
• pectin – recovered from the remains of processed fruit
• sawdust and bark- from the processing of logs into lumber
• straw- from grain harvesting

Minerals and petro chemicals

• asphalt – from the refining of crude oil
• fly ash – from the combustion of coal
• slag – from ore refining
• gypsum – from Flue gas desulfurization
• ash and smoke – from the combustion of fuel
• mineral oil – from refining crude oil to produce gasoline
• salt – from desalination

 Other

• sludge – from wastewater treatmen

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