Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2004
Publication Date: 8/1/2004
Citation: Muck, R.E. 2004. Effects of corn silage inoculants on aerobic stability. Transactions of the ASAE 47(4):1011-1016. Interpretive Summary: Unlike us, cattle do not like hot food. So the heating of corn silage caused by spoilage microorganisms can be a major problem for farmers. Farmers have increasingly been using silage inoculants (lactic acid bacteria) to make high quality corn silage, but these products have not been effective at keeping corn silage from spoiling when exposed to air. Inoculant manufacturers have been investigating new approaches to make corn silage less susceptible to heating. We tested many of these new products as well as standard ones over a three year period. Compared to corn silage made without an inoculant, the four standard inoculants caused the silage to heat on average 17 hours faster. A new inoculant made with new strains of the same types of lactic acid bacteria found in standard inoculants kept the silage cooler in one year of three. A standard inoculant plus sodium benzoate, a chemical used in human foods to prevent spoilage, was effective, but this product is not currently being marketed. We also tested a different type of lactic acid bacteria from those in standard inoculants, Lactobacillus buchneri. These bacteria can produce acetic acid, which inhibits the growth of many spoilage microorganisms. Silages made with Lactobacillus buchneri consistently spoiled more slowly than silage made with no inoculant. Overall, the Lactobacillus buchneri inoculants appear to be most reliable at keeping corn silage from spoiling and heating. These inoculants provide farmers with a good biological alternative to chemicals such as propionic acid or anhydrous ammonia for keeping silages cool at feeding time.
Technical Abstract: Aerobic stability of corn silage can be a major problem for farmers particularly in warm weather. Silage inoculants, while the most common type of silage additive, have not been consistently effective at improving aerobic stability. This study investigated new and proposed inoculant products over three years on corn silage in mini-silos. Three new approaches were tested: enhanced homofermentative inoculants, a standard inoculant plus sodium benzoate, and heterofermentative lactic acid bacteria (Lactobacillus buchneri). These approaches were compared with untreated as well as four standard homofermentative lactic acid bacterial inoculants. The standard inoculants on average reduced aerobic stability 17 h relative to that in untreated silage. The best enhanced inoculant increased stability one year in three. The standard inoculant plus sodium benzoate increased stability but was only tested in one year. The L. buchneri inoculants improved stability consistently all three years except in one case where one of these products had low viability. Overall, the L. buchneri products appear to be most consistent at improving the aerobic stability of corn silage of those commercially available.