We studied the effect of a lactic acid bacterial additive on the quality of silage made of grass-legume mixtures in the forest steppe zone of Mongolia. The use of lactic acid bacterial ferment positively influenced the diet digestion and the cows silage consumption. The cows ate well the silage treated with this method. They consumed it better by 10.6 percent and the organic matter digestion of the diet was higher by 6.1 percent (n = 6, P < 0.1) than the control group. Thus, as we accounted, due to the dairy cows effective utilization of fodder, it is possible to save 103.5 ton silage from 1000 ton.