Agriculture Reference
In-Depth Information
fibrous materials such as grass, straws and stalks, and it is fed mainly to cows and other
ruminants who have gastric systems designed to turn fibrous matter into protein.
The food we choose not to eat consists mainly of (a) surplus and spoilt grains and roots
(b) residues arising from food processing (c) kitchen waste, and (d) slaughterhouse waste.
These usually contain high levels of nutrients and are better fed to pigs or to poultry whose
gastric systems have evolved to digest highly concentrated food. Pigs, like humans, are
omnivores who have difficulty digesting significant amounts of fibrous matter and require
high concentrate foods to thrive. Cows are able to eat high protein foods such as grains but
they metabolize them inefficiently compared to pigs or poultry. However they can make up
for this by providing milk more efficiently than meat. That is why in Britain during the Se-
cond World War, the small amounts of animal feed at the country's disposal were directed
into increasing the number and performance of dairy cows, while the number of grain-fed
pigs and poultry were drastically reduced.
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Some idea of the amount of waste that is or could be going into the global pig bucket can
be gained from a more detailed examination of these four categories:
(a) Spoilt produce, and crops that fail to sell often never leave the farm so it is difficult to make any estimate
of their importance. Substandard produce is normally fed by mixed farmers to whatever stock they have on the
farm - whereas specialist arable farmers do not have this option to recoup some of their losses.
(b) According to California University food analyst J G Fadel, the processing byproducts of six major crop
classes (vegetable oil, sugar beet pulp, grain, citrus fruits, almonds and cotton) in 1993 amounted to about a quarter
of a billion tonnes of dry matter, which if fed to animals would supply enough energy to produce 435 million
metric tonnes of milk - more than the entire world's milk supply at the time, or about a quarter of a litre per person
per day.
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Milk provides over a quarter of all the nutrients provided by livestock in the world.
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These figures do
not include some other significant sources of waste such as potato or banana residues.
However, about a third of Fadel's figure consists of residues left over after making vegetable oils - mainly from
soybeans but also from groundnuts, sunflower and sesame seeds. These seeds can all be eaten whole by humans,
and in the case of soybeans the value of the meal for animal feed is as high as the value of the oil. There is therefore
doubt as to whether these oilseed meals should be regarded as a co-product, or a by product - a matter which is so
convoluted that it requires coverage in a separate chapter (Chapter 6). Even so, the other residues and co-products
identified by Fadel represent a prodigious quantity of nutrients which for the most part are already consumed by
animals. The production of oil and ethanol for energy purposes also leaves behind a substantial volume of meal
or of distillers' waste that can most profitably be used for animal feed; but using grains and oilseeds for biofuel is
highly inefficient and there are widespread calls for it to be discontinued.
(c) In the industrial countries, oil seed residues are probably dwarfed by the domestic waste stream. According
to a report from the government sponsored organization WRAP, UK households now throw away around a third,
by weight, of all the food they buy, somewhere between 6.7 and 8.3 million tonnes. A further 8.7 million tonnes is
thrown away by manufacturers, retailers and restaurants.
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Quite a high proportion of this is high value foodstuffs
- for example about 25 per cent of all bread and bakery products are wasted.
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The Labour government's food
