Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 2/13/1997
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: In making silage, the farmer must decide if an additive is warranted and if so, which product is best for the circumstances. This review discusses the principal types of silage additives in the U.S., focusing on how they affect silage quality and when each type may be utilized most effectively. The most common silage additive is the bacterial inoculant which supplies selected strains of lactic acid bacteria (LAB) to the crop. These products help guarantee a fast and efficient silage fermentation, improve dry matter (DM)recovery from the silo, may improve DM digestibility but have little effect on aerobic stability. These products are not always effective, primarily because they must compete with the LAB naturally on the crop. A simple system for estimating LAB numbers on alfalfa makes it possible for farmers to know when an inoculant will be most profitable in making alfalfa silage. Nonprotein nitrogen (NPN) additives (anhydrous ammonia, urea) are used in parts of the U.S., most often in making corn, sorghum and small grain silages. These products increase the crude protein content and aerobic stability of the silage. They increase pH and the level of fermentation products in most silages and may reduce dry matter recovery from the silo slightly. NPN additives are not recommended for hay crop silages. Enzyme additives are used to reduce fiber and increase sugar contents of crops. They are most effective in fiber breakdown in grasses of less than 40% DM. They increase effluent problems in wet silages and are best targeted for grass silage in the 30 to 40% DM range. In this DM range, fiber breakdown enhances silage compaction, reducing DM losses. Propionic acid is most often applied to heating silages but some products are applied at ensiling, primarily to improve aerobic stability.