The purpose of this investigation was to recognize, to select and to e
valuate shrub and tree species with forage potential as a way to promo
te their systematic use as food for sheep. This research took place in
five indigenous communities of Chiapas, Mexico, By means of interview
s with producers, a list of 37 species was obtained, of which 14 were
selected for evaluation based upon: a) their frequency of use; b) pres
ence of foliage during the drought season (winter); c) local abundance
and d) chemical composition and concentration of toxic substances, Am
ong the 14 selected species, six were shrubs and eight were trees. All
these species were available all year round. The 14 species showed in
vasive tendencies and different quantities outside the communities tha
n 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 ene
rgy (GE) between 2.9-4.5 kcal/g; neutral detergent fiber (NDF) of 21-5
9%; 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, abu
ndance, frequency of use and chemical composition, Rapanea juergenseni
i, Buddleia sp., Eupatorium semialatum and Ostrya virginiana, are cons
idered as feasible to be incorporated into the diet of the sheep in th
e area studied and as a result, it is necessary to make later diet and
agronomic evaluations. (C) 1997 Elsevier Science B.V.