Raw Soybeans: Raw soybeans should not be fed to poultry. When feeding soybeans to poultry, soybeans must be heattreated to destroy a trypsin inhibitor that disrupts digestion. The presence of the trypsin inhibitors will also cause an enlarged pancreas (a 50%-100% increase). The side affects will occur at inclusion levels as low as 5%. Soybean Roasting Soybeans are roasted to breakdown the trypsin inhibitor. A urease test is done afterwards to determine if breakdown is sufficient. There are many different opinions on the methods and temperatures required for this process. The most common recommendation is heating to 270o for 20 minutes when roasting whole soybeans. From http://ucanr.edu/sites/placernevadasmallfarms/files/102993.pdf
How about this discussion? Does it mean that chicken can consume fermented soybeans? http://www.naturalnews.com/025513_soy_food_soybeans.html
Fermented soy is good stuff. We eat a lot of tempeh and miso. Occasionally I have some natto. Our chickens love leftover tempeh. I don't know what traditional methods (ie, methods from 3000 years ago) did to the soybeans before fermenting them, but all the recipes I have seen for fermented soy products involve cooking the beans first. If you find recipes for fermenting soy for livestock use, in which the soy has never been heated, do let us know.