Using barley in poultry diets-a review

Barley can be included in poultry feed as an energy source. The carbohydrates in barley, however, are not as easily digested as those in corn because of the presence of nonstarch polysaccharides (NSP). The carbohydrates in corn grains are typically 65 to 70% starch and 11 to 14% fiber. The fiber in corn contains low levels of NSP, such as β-glucans, lignin, and cellulose. In contrast, barley grain typically contains 60% starch and 22% fiber. In addition, barley fiber contains higher levels of NSP than corn. Although the starch in barley is not as easily digested as that in corn, barley does have higher protein content. Nutritionists use nutrient composition tables to formulate least-cost rations that meet the nutrient requirements of animals. The energy content of barley can vary widely, and this variation is not reflected in the table values. Levels of β-glucans in barley are affected by the cultivar, growing conditions, geographic location, condition at harvest, and storage conditions. The age of the animal being fed is also important. The digestive tract undergoes changes and becomes more efficient at digesting ingredients as the animal ages. Older birds are more able to utilize barley than are young chicks. The ME values for viscous cereals, such as barley, obtained with adult birds do not appear to be applicable to young chickens. The use of feed enzymes in barley-based diets reduces intestinal viscosity, improving the feeding value of barley. Enzyme supplementation also reduces the variation noted for the feeding value seen with unsupplemented barley-based diets. Feeding barley cultivars with widely different β-glucan levels gives similar growth performance when supplemented with dietary enzymes. Enzymes also improve the litter quality of poultry raised on barley-based diets.