Effects of Adding Molasses and Lactic Acid Bacteria on the Fermentation Quality of Mixed Silage of Oat Straw and Perennial Ryegrass

To improve the fermentation quality of mixed silage of oat straw and perennial ryegrass and enhance the utilization efficiency of oat straw resource in Tibet,the mixture of oat straw and perennial ryegrass(4:6) were ensiled with different additives.The treatments were designed as follows;control,lactic acid bacteria(LAB,1×10~6 cfu ? g~(-1)FW),molasses(4%FW) and LAB + molasses,six reduplicate silos per treatment.The fermentation quality was analyzed after ensiling 60 days.Molasses or/and LAB additives significantly decreased the pH value,ammonia/total N(AN/TN),propionic and butyric acid contents of mixed silage(P0.05),while significantly increased the lactic/acetic acid ratio and lactic acid contents of mixed silage compared to control silage(P0.05).The silage added with molasses had higher lactic acid and water soluble carbohydrate(WSC) contents than the one added with LAB.However,there was no significantly different fermentation quality between the silage added with molasses and the one added with LAB + molasses.Therefore,it was suggested that 4%molasses additive was suitable to improve the fermentation quality of mixed silage of oat straw and perennial ryegrass in Tibet.