Enzymes in Silage

Some silage additives include enzymes.
What are they and what do they do?

The use of enzymes is well established in a broad range of industries.  The food and beverage industry uses enzymes since thousands of years in processes such as the production of sauerkraut or fermented soy products, or for the production of alcoholic beverages.  Enzymes are produced by bacteria and fungi, or during the germination of seedlings and grains. Making malt from barley basically means to provide a complete natural enzyme package for the brewer that enables him to convert sugars into alcohol. Enzymes basically are little protein particles that show the capability of breaking down larger molecular structures like carbohydrates into smaller fractions. By doing this they are very specific: like a key that fits to a specific lock enzymes are designed (by nature) to fulfill a specific task. There name is made up of the structure they work on plus the ending “–ase”. A hemicellulase breaks down  hemicellulose (fiber), a protease breaks proteins, and an amylase breaks amylose which is starch, and so on. Since the early 80s feed industry uses enzymes as feed additives to enhance the digestibility of certain feedstuffs and increase feed conversion, especially for monogastric diets. Over the past few years, enzymes have now also found their way into modern silage additives. But why?

The purpose of silage production is to preserve as many nutrients as possible and to maintain the quality of the harvested roughage.  This is mainly achieved through the exclusion of air and the achievement of a fast pH drop to quickly stop microbial detoriation or the growth of molds.  Traditional silage additives were made of a combination of acids or acid producing bacteria.  These bacteria live on available sugars and stop their activity once their nutrients are chewed up.  The result can be that now harmful bacteria take an advantage or that the pH value of the silage may not have dropped as far as it should.  Therefore, the idea came up of feeding the beneficial bacteria with sugars, for example, through the addition of molasses.  At a first glance, this looked like a good idea, but the problems that were observed were an uncontrolled growth of unwanted bacteria and a fast growth of molds after the opening of the silage pit.  Modern silage producers therefore looked for a more controlled form of feeding the acid-producing bacteria and found an answer in the food and alcohol industry.

The addition of defined enzyme combinations parallely to the inoculation with lactic acid producing bacteria allows a controlled and continuous release of available sugars for the bacteria.  The beneficial bacteria always find an ideal feed stock and are never over feed or starved to death. Like spoon-feeding a baby, the enzymes provide just as much food to the bacteria as these can digest.  The advantages are to control the need of the cultured bacteria and not to leave any feedstuffs for harmful bacteria or the growth of molds.  The most valuable result to the farmer is that the less of nutrients in the silage is minimized.

Michael Spandern

When choosing biological silage inocculants the farmer should therefore ask the salesperson or the consultant: 1) Which combination of bacteria is in the product? , 2) What do they do? 3) How are they fed? When clean, high quality roughage is harvested and the silage pit managed well, then modern silage additives made of a combination of lactic acid producing bacteria and enzymes, can eventually save nutrients and in this way of course money.