I came across this,and hope this helps someone, Do a search for [ Hawaii odorless pigs ] Very informative, almost like building a hugelculture berm in a building.Look for hawaii dept of agricuture [There is a lot of none english vidioes]
There is no big secret to it. Just keep them out on pasture and do rotational grazing. Then they naturally spread their manure and the pastures improve. Works great. We've been doing it for over a decade and have about 400 pigs on pasture.
Understand where you are coming from!! This is applicable to a very small acreage.The area is built with a none permiable bottom,then biochar, next wood logs then green matter,then finished with sawdust.this system may last 10 years!!! No flies No smell!!!
I have one managed rotational grazing setup that is only one quarter of an acre. That is 100' x 100' which is subdivided into 10 paddocks. That's enough to raise up from weaner to finisher three pigs using rotational grazing. You can do managed rotational grazing on very small parcels.
Reading further on the material it was said that the pasture system is the best!!!.This system was developed in Korea 40 years ago, because of lack of space.Also the need for odor and fly control. The similarity to making a hugelkulter mound and this housing system caught my attention !!! The system is in use in Asia and was even used in China because of the Olympics. [the security solders had brought their own pigs and needed odor control ]