Fodder shrub and tree species in the Highlands of southern Mexico

The purpose of this investigation was to recognize, to select and to evaluate shrub and tree species with forage potential as a way to promote their systematic use as food for sheep. This research took place in five indigenous communities of Chiapas, Mexico. By means of interviews with producers, a list of 37 species was obtained, of which 14 were selected for evaluation based upon: a) their frequency of use; b) presence of foliage during the drought season (winter); c) local abundance and d) chemical composition and concentration of toxic substances. Among the 14 selected species, six were shrubs and eight were trees. All these species were available all year round. The 14 species showed invasive tendencies and different quantities outside the communities than inside the communities. The values of ecological importance (1.9–4.4) were similar or higher to those found (1.96) in oaks (Quercus spp.), which is the dominant tree species in the region. The foliage of the 14 species contained crude protein (CP) levels of 7.2–22.3%, gross energy (GE) between 2.9–4.5 kcal/g; neutral detergent fiber (NDF) of 21–59%; acid detergent fiber (ADF) of 18–51%; tannic acid 0.42–0.69 g/100 g, absence or low content of cyanogenic glucosides and low, moderated or high contents of alkaloids. Based on the distribution patterns, abundance, frequency of use and chemical composition, Rapanea juergensenii, Buddleia sp., Eupatorium semialatum and Ostrya virginiana, are considered as feasible to be incorporated into the diet of the sheep in the area studied and as a result, it is necessary to make later diet and agronomic evaluations.