Tuesday, December 28, 2010

In defence of omnivory

A key concept reoccurring in my environmental studies degree at KU was the 10% rule.  For every step in a food chain (such as from grain to mice to hawks) only 10% of the energy required to grow the prey is passed to the predator.  In other words, the top predators in a food chain are the least efficient at using the energy that comes ultimately from the sun.  A logical extension of this concept is that feeding people on plants is more efficient than feeding plants to animals and eating the animals.  Think of the additional people that could be fed on existing world food supplies by cutting animals out of the plan.

Bluestem Farm organic pasture
Bluestem Farm conventional crop land leased to neighbors
I struggled with this as an young omnivore until I realized people foods (mainly grain) do not need to be fed to livestock.  If animals can make use of food sources that are unusable to humans (grass, weeds, bugs, etc.) then they can provide people with a high quality diet without subtracting from calories available elsewhere. That's why our goal at Bluestem Farm is to grow all our livestock on grass.  We're not there yet.  Some animals are an easy fit; cows, sheep, and goats are all ruminants that thrive on grass.  Others require an omnivorous diet; chickens and pigs have simple stomachs and need more protein in their diets than grass can provide.  One possible solution is to feed grass-fed cow or goat milk to chickens and pigs. 

The moral justification of eating meat can be summed up for me by these two views of our farm in winter.  The first is the habitat created by grass-fed beef production.  This land supports bugs, birds, snakes, rodents, deer, coyotes, and a host of soil-dwelling microbes.  The second is the habitat created by soybean monoculture.  It is devoid of life in winter, offering neither food nor shelter to wildlife.

1 comment:

Don said...

I absolutely LOVE your blog and what you are doing! Kim and I have always subscribed the the exact same practices!