Integrating woody species into livestock feeding in the Mediterranean areas of Europe

Woody species are indispensable sources-of animal feed in southern Europe, particularly in areas with dry to semi-dry Mediterranean climates. Such species can alleviate feed shortages, or even fill feed gaps in the winter and especially in the summer, when grassland growth is limited or dormant due to unfavourable weather conditions. These include several spontaneous shrubs and trees, which are essential components of natural communities such as shrublands and woodlands. They cover large areas and constitute grazing lands for all domestic animals, mainly goats. Forage production and nutritive value vary widely among species and varieties. In general, they have a low content of CP and are high in fiber and ash. These nutrients vary greatly according to season, with a higher concentration of fiber and ash and a lower content of CP during summer. Their nutritive value, however, does not always relate to their chemical composition due to the presence, in most species, of secondary compounds such as tannins, alkaloids, saponins and oxalates which limit nutrient utilisation and reduce animal performance. In contrast, a number of native and introduced species have been selected for artificial plantations. The most important of them include tree medic (Medicago arborea L.), Mediterranean saltbush (Atriplex halimus L.), old man saltbush (A. nummularia Lindl.), tagasaste (Chamaecytisus proliferus Link subsp. palmensis [Christ.] G. Kunkel), false indigo (Amorpha fruticosa L.), bladder senna (Colutea arborescens L.), white mulberry (Morus alba L.), black locust (Robinia pseudoacacia L.) and honey locust (Gleditsia triacanthos L.). All these species are nutritionally superior to most spontaneous species and methods of strategically integrating them into Mediterranean production systems are discussed. (c) 2007 Published by Elsevier B.V.