Enzymes are:
•  Proteins
•  Catalysts
•  Naturally
•  Highly specific

Enzymes are proteins with a highly complex three dimensional molecular structure. They only act under very specific reaction conditions (temperature, pH, and humidity) and only with their specific substrates. Enzymes are highly effective biological catalysts which can be found in all biological systems. They accelerate chemical reactions sometimes by as much as -fold which would otherwise, under the usual conditions prevailing in the organism, proceed only very slowly or not at all. Moreover, it is enzymes which make possible a controlled succession of chemical reactions in biological systems. They are not spent during the reaction, but catalyse and return to their original state once the reaction is complete. For this reason the amount of enzyme required is very small compared to substrate.

Enzymes are produced by all living organisms such as micro-organisms, plants and animals and thus are present in all cells as well as in extracellular spaces. Enzymes added to feedstuff are broken down in the digestive tract in the same way as other proteins. Hence there are not any residues to be found in the faeces or liquid manure, nor is it necessary to observe any withdrawal period before animals fed on enzyme supplemented diets can be slaughtered. Because enzymes are highly specific for the reaction they catalyse, it may be beneficial to add a mixture of different enzymes to the feed in order to be able to break down several unfavourable substances at the same time. When using an enzyme mix it has to be ensured that these enzymes will all act under the same reaction conditions. If this prerequisite is met, as for example in multi-enzyme systems, their application is often superior to that of using individual enzymes.