Agriculture Reference
In-Depth Information
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The average for all three meats is about 7.2:1; if we were to include eggs, milk and fish the average ratio would
be lower still. Since 1993 the feeding of grain to pork and poultry has increased much faster than the feeding of grain to
beef so the average feed conversion ratio for all meat is dropping. Sheep, goats and other ruminants are omitted because
they represent a comparatively small proportion of the global meat industry, and their performance is broadly similar to
that of cattle. Source: Figures derived from tables 4.17 to 4.24 in CAST, Animal Agriculture and Food Supply, 1999.
)
Although CAST's feed conversion ratios are higher than CIWF's, it is what each does
with them that makes the difference. Both sides use them to support their ideological posi-
tions, and in both cases they misrepresent the real state of affairs.
CIWF present their figures in a table with a comment in the main text, that 'from table 3
it is evident that to promote vast increases in meat production as an answer to world hunger
has one overriding limitation - it depends upon an inefficient (and also a relatively expens-
ive) product.' While this is true, the report fails to note that there are a number of other
factors which combine to lower the ratio between meat and grain, to the point where it is a
good deal more slender than their table suggests.
CAST, on the other hand, adjust their conversion ratio downwards by whatever means
they can find, fair or foul. Mostly these means are quite reasonable; but by a statistical
sleight of hand, which I shall come to in due course, they manage to conclude that there
is no practical difference in performance between meat and grain consumption, and 'thus
diverting grains from animal production to direct human consumption would, in the long
term, result in little increase in food protein.' This is a flagrant lie.
To understand how both sides have applied the figures, it is necessary to examine in
some detail the main ways by which the feed conversion ratios in the table above have to
be adjusted downwards, and under what circumstances. There are three subsidiary reasons
for reducing the ratios (relating to the nutritive value of meat, the byproducts of meat, and
the superior yields of some animal feed crops) and one overriding reason - the ability of
animals to consume food that humans can't eat.
Nutritional Value
The nutritional value of meat is different from that of grain, and varies according to the
proportion of muscle to fat. Weight for weight, lean meat tends to have more protein than
grain, but slightly less energy, while very fatty meat can have more energy than grain, but
less protein.
The quality of most meat protein is generally regarded as higher than that of some veget-
able protein, for example rice which is low in lysine. According to Pimentel, meat protein
is '1.4 times more nutritious for humans than the comparable amount of plant protein,' and
CAST agrees 'the biological value of protein in foods from animals is about 1.4 times that
