Effects of Temperature, Moisture, and Aeration on Fermentation of Alfalfa Silage

Abstract

Effects of temperature, aeration, and DM on fermentation of alfalfa were evaluated. Third cutting alfalfa at 46 and 62% DM was ensiled for 21 d in laboratory silos maintained at 38 and 65°C, and subjected to aerated and anaerobic conditions. Samples were withdrawn at d 1, 2, 7, and 21 and analyzed for DM, pH, VFA, lactic acid, NDF, ADF, ADIN, lignin, ash, total N, NPN, and NH3N. Dry matter loss, calculated from ash content, ranged from .2% DM for d 1 to 2.7% DM on d 21. Low DM silages contained more lactate and acetate than high DM silages. High ensiling temperatures reduced production of organic acids. Slight molding took place in most of the silages at low temperature. Analysis of the fiber fractions revealed an increase in NDF and ADF, particularly in high temperature silages. The percentage increase was greater for NDF than ADF in high DM, high temperature silages. Concentrations of NPN were greater in low DM silages than high DM silages, but high DM silages contained the most ADIN. Lignin and ADIN increased in high temperature silages, but the latter was not greater than .4% of DM after 21 d in the silo.