Anna
This is a fascinating issue, regarding which I have taken great delight in
offending vegetarian/vegan enthusiasts over many years!
Ignoring the ethical dimension for a moment, my argument is that it is
informative to consider this in terms of the efficiency of production of
human food. Efficiency has a numerator and a denominator, and if (as is
so often done by vegetarians) the denominator is chosen as feed input to
the animal, and the numerator as human food produced, then we get the
familiar <10% efficiency of the animal system. IF (and it's a big if),
that feed input to the animals is suitable/acceptable as food for humans,
then the place of animals in the food chain is definitely questionable.
But, as others have pointed out, much of what animals, and particularly
ruminants, eat is either inedible or unacceptable to humans. And much of
the land that is available is, for topographic or climatic reasons, best
suited to the production of grass and other primarily cellulosic material
useful only to ruminants. So if we start to consider efficiency in terms
of food produced per area of available land, then achieving some
production (however "inefficiently" by the preceding calculation) has to
make sense. A similar argument also applies to food wastes, rejected by
humans but still acceptable to pigs and poultry - why waste these items
when they can be converted into highly desirable foods?
The organic/non-organic aspect is not specially relevant here, although
the potentially enhanced recycling of nutrients via the animal actually
reinforces the argument.
There is a futher subtlety that has interested me for some time, but which
it has not been possible to quantify. For good physiological reasons, the
basic feed conversion efficiency of the animal (feed to food) is higher
the faster the animal grows or the more milk it produces per day.
Simplifying considerably, high growth rates require high energy density in
the feeds, but such feeds (cereals etc) may valuable to feed humans
directly. However, a small diversion of such feed/foods to the animal
industries <<might>> make sense if it were thereby possible to increase
the efficiency of feed conversion of those industries enough to compensate
for the diversion.
The ethical dimension regarding slaughtering is possibly unanswerable
except from a particular moral position, but from experience, old animals
don't always die nice, peaceful deaths. Just maybe, slaughter is often
inevitable. So is it then sensible/ethical not to consume the carcase?
Dick Morris
Senior Lecturer in Systems
Open University
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