From an animal nutrition point of view, legumes can be divided into two groups: fodder legumes (e. g. lucerne) mainly utilized in ruminant nutrition, and grain legumes (e. g. faba beans, peas, lupins) mainly used in bird and swine nutrition and, to a lesser extent, in ruminants. Grain legumes can partially or even totally replace traditional protein sources of animal origin such as meat, bone and fish meals. Moreover, they represent an alternative protein-rich feed ingredient for soybean meal and other oilseed meals. Their average protein content is variable but high (25-45 g / 100 g dry matter). However, the presence of secondary plant metabolites such as protease inhibitors, saponins, lectins, glycosides, tannins, and alkaloids, and their high levels of fiber (non- starch-polysaccharides) have restricted the use of legume-grains in monogastric (poultry and pigs) and ruminant feeding. In spite of this, the interest in, and the number of studies on, these resources as functional food products, especially in human, but also in animal, nutrition, are still on the increase. The ban on the use of animal proteins such as meat and bone meals, which took place in the EU as a consequence of the BSE crisis, has boosted the interest for the use of vegetable proteins, preferentially of local origin, in animal feeds. In order to establish the nutritional value of legumes, particular attention must be paid to their nutritional composition, energy content and amino acid digestibility. In ruminants, the degradability in the rumen of the protein, individual amino acids and carbohydrates are not well known and must be established. Approaches into the presence of tannins in ruminant feeds are currently changing due to their potential beneficial effects on nutrient degradation in the rumen, and on product quality or methane mitigation. Soybean is the raw material preferentially utilized as a protein source in animal feeds, but the great dependency on imported soybean and the fact that most is genetically modified are barriers to its utilization in the EU. In summary, environmental, health and productive considerations result in a growing interest in legume production in the EU.
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