An omnivore's dilemma

Tonight I re-watch the documentary Food, Inc. It advocates a reduction in factory farming of all types, especially animal farming, and an increase in organic farming in lieu of commercial fertilizers.

But here's a question that pops up in my mind....

How do you increase organic farming, which requires manure, while decreasing animal farming – which is what produces manure?

An 'omnivore's dilemma' indeed.