Soybeans do not "pass through" a cow.   They are VERY easily digested.   Too easily.   Let cows get into soybeans "free choice" and you will quickly have some very over-inflated cows.  BTDT.   Antidote is  pepto-bismal by the gallon along with  vinegar  and mineral oil and in more severe cases, a knife in the side to relieve the pressure.  Make sure you are holding your breath.