Digestive enzymes have been one of ITPSA’s main lines of interest in recent years, due to their proven efficiency and natural structure. First to appear were the carbohydrase type enzymes, mostly based on ?-glucanase (designed for diets containing raw materials with a high content mainly on ?-glucans, such as barley, rye and oats and their byproducts) and xylanase (designed for diets with raw materials with high amounts of xylans and ?-glucans, such as wheat, rye, oats and other cereals). Their use makes it possible to increase the feed energy value, at no extra cost.