Comparative studies on chemical composition and fermentation characteristics of corn silage

Abstract

A commercial bunker silo and three types of experimental silos were used for determination of chemical composition and fermentation characteristics of corn silage (27.3% DM and 8.4% CP) ensiled in two different densities (400 or 600kg of silage/m³): 1) commercial bunker silo sampled at 0, 50 and 100 cm from the top; 2) plastic silo with bulsen valve; 3) plastic bag; and 4) concrete pipe. Dry matter and CP concentration showed larger variation among different levels in the commercial silos and were intermediate in the experimental ones. This indicated that water and nutrients translocation were greater in the commercial than in the experimental silos. Experimental silos well represented the commercial ones concerning cell wall, starch, water-soluble carbohydrates and IVDDM. In commercial bunker silo, pH value was low in the middle extract and higher on the top. Silage obtained from the middle extract presented greater values of NH3-N and lactic acid concentrations, while silage obtained from deep extract had higher acetic acid concentrations. Fermentation (pH, concentration of ethanol, acetic, propionic, butyric, lactic and ammoniacal N) in the experimental silos was similar to the commercial silos. Variation in fermentation in different extracts of commercial silos was greater than in different types of experimental silos