Life cycle analysis in animal agriculture

In Reducing the environmental impact of farming, I talked about Nathan Pelliter’s work on Agricultural Life Cycle Analysis as a way to evaluate which farming methods have the least environmental impact. While the ideas apply to any type of farming (or really to the production of anything), his main work is actually on animal agriculture.

The return on investment of most types of animal agriculture is small compared to that of plant agriculture. For example, cattle require about 6 pounds of feed to produce 1 pound of muscle. All of the water, fertilizer, and pesticides required to grow 1 pound of plant material is thus multiplied by 6 to produce 1 pound of beef. Granted, it isn’t quite that simple, as parts of plants that aren’t used for human food can be fed to animals, but the point holds, even in organic systems.