Effect of propionic acid on the storage stability of high moisture purple prairie clover (Dalea purpurea) hay

Purple prairie clover (PPC; Dalea purpurea) is an important legume that grows naturally on rangeland and has a feeding value similar to alfalfa. Baling hay with high moisture content is beneficial to shorten the field drying period and thereby reduce the risks of losses, but high-moisture hay is difficult to store as the high moisture content may result in degradation, loss of nutritive value, and sometimes toxic fungal growth in the stack. The effect of propionic acid on the stability of PPC hay bales with high moisture content was studied. The results indicated that PPC hay baled at high moisture content (28%) had similar chemical composition to those baled at low moisture content (17%). However, PPC hay baled at high moisture content was perishable and not easily stored. Inclusion of buffered propionic acid with at an appropriate rate in PPC hay bales baled at high moisture content was observed to significantly reduce the temperature in storage and forage pH, the neutral and acid detergent fibre levels, and numbers of bacteria, fungi and yeasts, especially after longer periods of storage (P<0.05), while at the same time increasing the crude protein and water soluble carbohydrate content of bales during storage. In summary, adding propionic acid to high moisture PPC hay bales, enhances their nutritional value, feeding safety and storage stability.