ARS | Publication request: Improving alfalfa silage quality with inoculants and silo management

Submitted to: Cornell Nutrition Conference for Feed Manufacturers
Publication Type: Proceedings
Publication Acceptance Date: October 21, 2008
Publication Date: October 21, 2008
Citation: Muck, R.E. 2008. Improving alfalfa silage quality with inoculants and silo management. In: Proceedings of 2008 Cornell Nutrition Conference, October 21-23, 2008, Syracuse, NY. p. 137-146.

Technical Abstract: Two areas of silage management are addressed: silage inoculants and plastic film quality. Inoculants are the most common silage additives in the United States. These products contain lactic acid bacteria to supplement the lactic acid bacteria naturally on the crop and help insure a consistent fermentation in the silo. The standard type of silage inoculant that has been marketed for several decades contains one or more homofermentative species of lactic acid bacteria. Recently, a heterofermentative species, Lactobacillus buchneri, has begun to be marketed alone or in combination with homofermentative species. The homofermentative inoculants shift fermentation toward lactic acid, lower pH, improve dry matter recovery from the silo and can increase milk production in lactating cows or gain in growing cattle. Lactobacillus buchneri shifts fermentation toward acetic acid, which helps inhibit yeasts and molds that spoil silage aerobically. Combination inoculants seek to provide the best traits of both types of inoculant species, but published research has only confirmed the changes in silage fermentation, not effects on animal performance. Choice of inoculant type should depend on the primary goal for using an additive: avoiding a clostridial fermentation, improving aerobic stability or making a good silage better. In alfalfa silage, homofermentative inoculants are the best choice for all three goals with the exception of improving aerobic stability in alfalfa ensiled at drier than recommended levels. A plastic film, Silostop, is now available in the U.S. with an oxygen permeability that is only 5% of that in normal polyethylene. When used as a part of the Silostop system, this film provides substantial reductions in losses at the shoulders of bunker silos compared to normal polyethylene film and tires. In the middle of the top surface, the Silostop system and a well-anchored, 8 mil white polyethylene provide similar losses, but silage quality under the Silostop film is slightly better. This new system provides farmers with an alternative to plastic and tires for sealing bunker and pile silos.