To prevent bad quality silage, mixes of formic and propionic acid and their salts are used to improve the ensilage process. Good silage needs a fermentation that is in an anaerobic environment, reaching the right pH and thereby saving nutritional value and dry matter content. Our acids and their salts help that process in the right direction for our customers.
The first organic acid to be used to improve silage quality is still a staple in most acid based silage additives.
• decreases pH
• saves nutritional value
• kills unwanted bacteria
Formic acid decreases pH and stops the plant cell respiration. It also kills unwanted bacteria such as Clostridium before they convert into spores. A fast decrease of pH maintains the content of crude protein in the feed by killing the crop and in doing so causes the plant enzymes to cease their proteolytic activity. The process in which the plant uses its own protein as an energy source results in the formation of ammonia. Ammonia lowers the palatability in the feed and also decreases the crude protein quality.
Formic acid preserves the energy in the feed by instantly decreasing the pH and thereby saving energy that otherwise would have been used by the lactic acid bacteria to lower the pH.
Propionic acid is added to silage additives for other benefits than formic acid. The two work in synergy, as propionic acid:
• inhibits mold and yeast growth
• prevents heating processes
Propionic acid inhibits molds and yeasts. This prevents heating of the silage. Week acids can penetrate the cell wall of e.g. a fungal cell. The cell tries to repair itself and uses a lot of energy for this. Eventually the cell will have used all its energy and dies. Week acids can also bind to e.g. a yeast cell’ mem-brane protein and change its characteristics so that it loses its function. Even if the feed has a storage stable pH, there is a risk of yeast growth if oxygen is available. Yeast uses lactic acid as a nutritional source, which results in a higher pH in the silage and other unwanted microorganisms can start to grow and spoil the silage. Silage with a high dry matter content and a high sugar content has an in-creased risk of yeast and mold growth when the silo is opened. This can be prevented by propionic acid. Indication of yeast growth is measured in ethanol.
Sodium formate and sodium propionate
Sodium formate is the salt from the formic acid and it is effective against unwanted bacteria such as Clostridium. Sodium propionate is the salt of propionic acid. Just like propionic acid it is effective against molds and yeast. The latest generation of silage additives uses these salts with great success to improve the safety of handling and transport.