▁When ▁a ▁sil o ▁is ▁filled , ▁fine ▁dust ▁particles ▁in ▁the ▁air ▁can ▁become ▁explos ive ▁because ▁of ▁their ▁large ▁aggregate ▁surface ▁area . ▁Also , ▁fer ment ation ▁presents ▁resp ir atory ▁ha z ards . ▁The ▁ens iling ▁process ▁produces ▁" s ilo ▁gas " ▁during ▁the ▁early ▁stages ▁of ▁the ▁fer ment ation ▁process . ▁Sil age ▁gas ▁contains ▁nit ric ▁ox ide ▁( NO ), ▁which ▁will ▁react ▁with ▁o xygen ▁( O 2 ) ▁in ▁the ▁air ▁to ▁form ▁nit ro gen ▁dio x ide ▁( NO 2 ), ▁which ▁is ▁to xic . ▁L ack ▁of ▁o xygen ▁inside ▁the ▁sil o ▁can ▁cause ▁as phy xi ation . ▁M olds ▁that ▁grow ▁when ▁air ▁reaches ▁c ured ▁sil age ▁can ▁cause ▁organ ic ▁dust ▁to xic ▁synd rome . ▁Col laps ing ▁sil age ▁from ▁large ▁b unker ▁sil os ▁has ▁caused ▁death s . ▁Sil age ▁itself ▁pos es ▁no ▁special ▁danger . ▁ ▁N ut r ition ▁Ens il age ▁can ▁be ▁subst it uted ▁for ▁root ▁cro ps . ▁ ▁Bul k ▁sil age ▁is ▁commonly ▁fed ▁to ▁da iry ▁cattle , ▁while ▁b aled ▁sil age ▁tends ▁to ▁be ▁used ▁for ▁be ef ▁cattle , ▁sheep ▁and ▁horses . ▁The ▁advantages ▁of ▁sil age ▁as ▁animal ▁feed ▁are ▁several : ▁ ▁During ▁fer ment ation , ▁the ▁sil age ▁b acter ia ▁act ▁on ▁the ▁cell ul ose ▁and ▁car bo h yd r ates ▁in ▁the ▁for age ▁to ▁produce