A Model of Alfalfa Hay Storage

Abstract

ABSTRACT ALFALFA hay baled at various moisture contents and densities was placed into storage where dry matter loss, temperature and quality changes were measured. A two-way analysis of variance indicated that baling moisture (p < 0.01) and moisture times density (p < 0.02) significantly affected dry matter loss; storage temperatures were positively correlated with moisture and density (p < 0.01). Sensible heat generation rate during the first 30 days in storage was affected by baling moisture, density and moisture times density (p < 0.0001). From the data, semitheoretical models predicting storage changes in alfalfa hay were developed and validated. Dry matter loss was a function of the sensible heat generated and moisture lost during storage. A finite difference heat transfer model and storage temperature data were used to estimate heat generation rate over time. The rate increased during the first several days of storage and decreased thereafter. Total amounts of acid detergent fiber and ash did not change during storage; however, concentration increases occurred due to loss of non-fiber, non-ash dry matter. Crude protein loss was 40% of that of other dry matter which resulted in a small increase in protein concentration. The amount of acid detergent insoluble protein increased in proportion to the degree days for which stack temperature exceeded 35C..