Effects of propionic acid on preservation and quality of baled moist hay

At the Swiss Federal Research Station for Animal Production at Posieux, four conservation methods were compared and their impact on forage quality was investigated. The evaluation of propionic acid as preservative for moist hay was of particular interest. Three roughage types were harvested: a late first cut as well as an early and late third cut. Each cut was conserved according to the following procedures: moist hay without preservative, moist hay with preservative, big bale silage wrapped with stretch film, barn dried hay. In the three first variants the forage was pressed with a cubic baler. The evaluation of the efficacy of propionic acid as preservative for moist hay did not yield satisfying and clear results. Even though the classical analyses revealed some differences between treated and untreated hay, the extent is of no importance. In both cases, hay quality suffered from heat damage. The poor quality of treated hay is obviously attributable to technical problems. On the other hand, the strongly wilted big bale silage yielded good quality roughage.