EFFECT OF STORAGE-SYSTEM AND DRY-MATTER CONTENT ON THE COMPOSITION OFALFALFA SILAGE

The objectives of this study were to evaluate the effects of dry matte r (DM) content and three different storage systems on the quality of a lfalfa ensiled on commercial farms. Alfalfa silage samples were collec ted from 21 bunker silos, 20 silos that limited oxygen infiltration, a nd 19 tower silos on 43 commercial dairy farms. Storage system and DM content were confounded because silages from bunker silos generally we re wetter than silages from O-2-limiting and tower silos. There was no effect of storage system on crude protein content of the silages. How ever, silage from bunker silos had higher concentrations of nonprotein N, NH3 N, and acid detergent insoluble N than did silages from the ot her two storage systems. The proportion of total N in neutral detergen t insoluble N minus acid detergent insoluble N was greatest in silage from O-2-limiting silos. Fiber components were affected by storage sys tem; silage from bunker silos had the greatest concentration of acid d etergent fiber and neutral detergent fiber. Concentrations of acid det ergent fiber and neutral detergent fiber were higher in wetter silages from bunker silos, but DM content did not influence fiber content of silages from O-2-limiting and tower silos. Concentrations of total org anic acids, acetic acid, and butyric acid were highest in silages from bunker silos. The general effects of DM on the quality of silages obt ained from commercial dairy farms were similar to results obtained fro m laboratory-scale silos.