Enzymes are proteins that help speed up metabolism, or the chemical reactions in our bodies. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A “substrate” is the portion of the feed that the enzyme will break down to release the nutrients bound to it. It is similar to a “lock and key” concept, where the substrate is the lock, and the enzyme is the key. If there is no lock, then it becomes absolutely pointless to buy a key! Therefore, it is important to consider what substrates (i.e. ingredients) are prevalent in your diets to best determine which enzyme(s) you should include for optimal results. In the field of nutrition and applied feeding programs, one area in which producers have adopted improved technology is the use of feed enzymes. The advantages of using commercial enzymes in poultry feeds include improved productive performance and feed utilization, minimized environmental pollution due to reduced nutrient of manure.