Storage of small bale silage and haylage–influence of storage period on fermentation variables and microbial composition

Abstract

Abstract An experiment investigating changes in fermentation variables and microbial composition during storage of small‐bale silage and haylage was performed. Haylage was defined as silage with a dry‐matter (DM) content exceeding 500 g kg−1. Grass was wilted to three different DM contents, and baled into silage (350 g DM kg−1), haylage with a low DM content (550 g kg−1) and haylage with high DM content (700 g kg−1) in small rectangular‐shaped bales (0·80 m × 0·48 m × 0·36 m) that were individually wrapped. Bales were stored for short (2 months) or long (14 months) periods before opening and sampling. Silage had higher concentrations of fermentation products and a lower pH than either of the two haylage types. In general, long‐term storage influenced all fermentation variables except concentrations of butyric acid and succinic acid, and yeast counts were higher after 14 months than 2 months of storage. However, silage changed in more fermentation variables during storage than the two haylage types. Although differences between short‐ and long‐term stored silage were found, linear correlations between short‐ and long‐term stored bales were present for all chemical variables. Pearson's correlation coefficients were highest for lactic acid, followed by pH.