The data on assessment the preservative action of new enzymatic multisystem in combination with bacterial silage additive Silzak at alfalfa ensiling are presented in this study. It is known that alfalfa is a nonensiling legume grass because of excess moisture, sugar deficit and high content of crude protein. The experiments on alfalfa ensiling were conducted with application the enzymatic multisystem FM-1 under laboratory and research-and-production conditions. The multisystem was developed by the specialists of science-and-technical centre «Lecbiotech» in cooperation with scientists of Williams Fodder Research Institute. The optimal dose of FM-1 application and its preservative effectiveness in comparison with chemical conservant were determined in technological experiments. Obtained silage was evaluated on basic parameters: nutrients and organic acids content, ammonia, active acidity. The influence of the tested biological additive on the nutrients digestibility and energy value of alfalfa silage was estimated in experiments with hog lambs. Total results have shown the efficiency of the new development. Lucerne silage, prepared with application of mixture FM-1 and Silzak, was characterized by the better parameters of nutrients digestibility and energy value than at using a chemical conservant AIV 3 plus. The optimal dose of enzymatic multisystem application, as 90 gram per ton of fresh plant mass, was determined in the series of experiments.