Agriculture Reference
In-Depth Information
lowed me in examining all the above mitigating factors and circumstances are now in a bet-
ter position to appreciate how the feed conversion ratios that we began with (ranging from
around 4:1 for poultry and milk to around 13:1 for beef) translate into the FAO's global ag-
gregate of 1.4:1. In fact the FAO authors go on to argue the ratio may be near enough one
to one: 'While input is higher than output, if cereal preparation losses on the input side and
improved protein quality on the output side are considered, a reasonable balance emerges.'
They might also have added leather and other animal byproducts into the equation.
We are also now in a position to examine how both CIWF and CAST have used the fig-
ures to support their particular causes. Mark Gold, for the CIWF, in the section entitled
'The Inefficiency of Animal Foods - Food Conversion Rates' simply omits to mention the
superior nutritional value of meat, or the value of animal byproducts, or the possibility that
animal feed crops may be more productive than human crops; and he fails to acknowledge
the service which ruminants and pigs provide by turning inedible vegetation and waste into
human food. Grazing is only mentioned in a favourable light in the section entitled 'The
Value of Livestock to Poor Communities', as if it were acceptable in poor countries, but
not in wealthy ones.
The authors of the CAST report do refer to all these factors, although (being North
American) they play down pig waste, and emphasise ruminant use of grassland:
Poultry and pork production are the most efficient on the basis of total food pro-
duced from total food intake but, on average, ruminants return more human food per
unit of human-edible feed consumed because most of their feed is obtained from ma-
terials that cannot be consumed directly by humans. This fact has been overlooked in
some assessments of the role. On a global basis, less than three kilograms of grain are
required to produce a kilogram of meat from any of the species.
So far so good, but then a few lines later they continue:
It has been estimated that, on a global basis, animals produce a kilogram of human
protein for each 1.4 kilograms of human food protein consumed. The biological value
of protein in foods from animals is about 1.4 times that of foods from plants. Thus
diverting grains from animal production to direct human consumption would, in the
long term, result in little increase in total food protein.
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These paragraphs come from the 'Interpretative Summary'— the only part of the report
which can be viewed on the internet. Perhaps it was written and then grafted on to the
report by someone other than the scientists who drew up the main document. If the second
paragraph seems to make sense to you, read it again, it is worth dissecting in detail.
