Soybean hulls are a by-product of soybean processing for oil and meal production. Soybean hulls have urease activity, which can be a problem in rations containing urea. Heat treatment destroys the urease activity. Soybean hulls which have been heat treated are referred to as soybean mill run.
Soybean mill run is a palatable feedstuff for cows and calves. It contains a high level of very digestible fiber. It has slightly more TDN than beet pulp and oats, 93 percent of the TDN value of barley, and 88 percent of the TDN value of corn.
Also, great as a mushroom substrate!