The aim of study was the evaluation of influence of fertilization with manure on the nutritive value of meadow sward and their usefulness to silage production. In framework of study, mineral fertilization NPK (N-90 kgźha-1, P-22 kgźha-1, K-90 kgźha-1) and cattle manure (22 tźha-1) were compared. Cut and pre-wilted meadow sward was ensilaged in big bales. Bacterial inoculant Lactosil was added to a part of ensilaged material. In grass and silage samples the content of nutritive components, number of yeast, moulds, Enterobacteria and aerobic bacteria were evaluated. In silage samples additionally the dry matter content, pH, ammonium concentration and lactic and volatile fatty acids, content and aflatoxin B1 presence were analysed. Meadow sward fertilized with manure had higher protein and ash content and lower WSC content than sward from object fertilized with mineral fertilizer. The relation of WSC to protein was also adverse, that points at worse usefulness to ensilage of sward from abject fertilized with manure. Applied fertilization with manure had no negative effect on microbiological evaluation of herbage intended for silage. Silage made of sward fertilised with manure had worse values of indicators assessing chemical evaluation of silage than silages from sward fertilized with mineral fertilizers. Application of bacterial additive did not change significantly the parameters of chemical and microbiological assessment of silage. The results indicate the validity and usefulness of manure application as the natural fertilization of grasslands in the system of organic farming.