Preservation of high-moisture hay in storage through the use of forage additives

Abstract

Two inoculants, a buffered propionic acid formulation and anhydrous ammonia were compared for use as hay preservatives. Alfalfa forage was baled at three moisture levels: 15–20%, identified as low (L); 20–25%, identified as medium (M); 25–30% identified as high (H). Hay baled at the M and H moisture levels was treated with no forage additive (Con); anhydrous ammonia (NH3) applied to forage placed in the stack; buffered propionic acid (63% acid, Acid); two strains of Pediococcus pentosaceus (A) or a mixture of Pediococcus acidilactici and Lactobacillus plantarum (B) applied at the time of baling. Due to precipitation (34.1 mm), hay baled at the L moisture level had greater (P < 0.05) acid detergent fiber (ADF), acid insoluble nitrogen and chitin levels at the time of stacking than hay baled at M and H moisture levels. Storage conditions for hay baled at the M moisture level resulted in high dry matter (DM), crude protein (CP) and ADF retention and relatively moderate increases in chitin levels during storage for all treatments. Storage of hay baled at the H moisture level without use of a forage additive resulted in poor DM and nutrient retention, and marked increases in chitin concentrations during the storage period. H-NH3 and H-B improved (P < 0.05) DM, CP and ADF retention relative to H-Con. H-Acid improved (P < 0.05) CP retention whereas H-A had no positive effect on DM and nutrient retention. All forage additives improved (P < 0.05) the visual assessment of H moisture bales for mold and dust relative to H-Con; however, extent of fungal invasion as measured by chitin analysis was not reduced with the use of forage additive. Key words: Anhydrous ammonia, propionic acid, bacterial inoculants, hay preservation