Enzymes in Animal NutritionGrains play a major role in animal feed as energy sources. However, their use is limited to few choices like maize, wheat and rice when compared to other grains like barley, oats or rye. The initial reason attributed for this was their fiber content. This school of thought is now outdated and the most recent pointer is the nature of bonding in the sugars in feed, like beta-glucans in barley for example. For decades the use of enzymes in beverages was practiced, but the application of the enzymes in animal feeds has been brought to limelight only with the advent of biotechnology. The methodology for extraction enzymes from of microbes have been standardized making it easier for the feed manufacturers and nutritionist to incorporate substrate-specific enzymes for using economic ingredients without compromising their nutrient values. The application of the exogenous enzymes in animal diet has improved their digestion and performance both in healthy young ones and sick animals or animals under stress.