Potential of fodder trees and shrubs as animal feeds in the Mediterranean areas of Europe.

Fodder trees and shrubs are indispensable sources of animal feed in southern Europe, particularly in areas with dry to semi-dry Mediterranean climate. This is because they can alleviate the feed shortages or even fill up the feed gaps in the winter and especially in the summer period when grassland growth is limited or dormant, due to unfavourable weather conditions. They are spontaneous species, essential components of natural communities. They cover large areas and constitute grazing lands for all domestic animals, mainly goats. Productivity and nutritive value vary widely among species and provenances. In general, they have low protein content, high fiber and ash and low to moderate digestibility. Their feeding value however does not always relate to their chemical composition due to the presence in most species of anti-nutritional factors such as tannins, alkaloids, saponins, etc., which limit nutrient utilisation and reduce animal performance. A number of native and exotic species have been selected for artificial plantations. The most important of them include Medicago arborea L., Atriplex halimus L., A. nummularia Lindl., Chamaecytisus proliferus Link subsp. palmensis (Christ.) G. Kunkel, Amorpha fruticosa L., Colutea arborescens L., Morus alba L., Robinia pseudoacacia L. and Gleditsia triacanthos L. All these species are nutritionally superior to most spontaneous species and are recommended as strategic resources to complement natural grasslands.